what are the differences between ball mill and rod mill? | fote machinery

what are the differences between ball mill and rod mill? | fote machinery

Ball mill and rod mill are the common grinding equipment applied in the grinding process. They are similar in appearance and both of them are horizontal cylindrical structures. Their cylinders are equipped with grinding medium, feeder, gears, and transmission device.

The working principle of ball mill and rod mill machine is similar, too. That is, the cylinder drives the movement of the grinding medium (lifting the grinding medium to a certain height then dropping). Under the action of centrifugal force and friction, the material is impacted and ground to required size, so as to realize the operation of mineral grinding.

Grate discharge ball mill can discharge material through sieve plate, with the advantage of the low height of the discharge port which can make the material pass quickly so tha t to avoid over-grinding of material. Under the same condition, it has a higher capacity and can save more energy than other types of mills;

It is better to choose a grate discharge ball mill when the required discharge size is in the range of 0.2 to 0.3 mm. Grate discharge ball mill is usually applied in the first grinding system because it can discharge the qualified product immediately.

Overflow discharge ball mill can grind ores into the size under 0.2 mm, so it is very suitable for the second grinding system. The capacity of it is about 15% lower than grate discharge ball mill in the same specification, and the loaded grinding medium is also less than that one.

It can be divided into three types of rod mills according to the discharge methods, center and side discharge rod mill, end and side discharge rod mill and shaft neck overflow discharge rod mill.

It is fed through the shaft necks in the two ends of rod mill, and discharges ore pulp through the port in the center of the cylinder. Center and side discharge rod mill can grind ores coarsely because of its structure.

This kind of rod mill can be used for wet grinding and dry grinding. "A rod mill is recommended if we want to properly grind large grains, because the ball mill will not attack them as well as rod mills will."

It is fed through one end of the shaft neck, and with the help of several circular holes, the ore pulp is discharged to the next ring groove. The rod mill is mainly used for dry and wet grinding processes that require the production of medium-sized products.

The diameter of the shaft neck is larger than the diameter of the feeding port about 10 to 20 centimeters, so that the height difference can form a gradient for ore pulp flow. There is equipped with a spiral screen in the discharge shaft neck to remove the impurities.

It has high toughness, good manufacturability and low price. The surface layer of high manganese steel will harden rapidly under the action of great impact or contact. The harder index is five to seven times higher than other materials, and the wear resistance is greatly improved.

It has high toughness, good manufacturability and low price. The surface layer of high manganese steel will harden rapidly under the action of great impact or contact. The harder index is five to seven times higher than other materials, and the wear resistance is greatly improved.

It is made of several elements such as chromium and molybdenum, which has high hardness and good toughness. Under the same work condition, the service of this kind of ball is one time longer than the high manganese steel ball.

After the professional technology straightening and quenching processing process, a high carbon steel rod has high hardness, excellent performance, good wear resistance and outstanding quality.

The steel ball of ball mill and the mineral material are in point contact, so the finished product has a high degree of fineness, but it is also prone to over-grinding. Therefore, it is suitable for the production with high material fineness and is not suitable for the gravity beneficiation of metal ores.

The steel rod and the material are in line or surface contact, and most of the coarse particles are first crushed and then ground. Therefore, the finished product is uniform in quality, excellent in particle size, and high in qualification rate.

The cylinder shape of the rod mill and the ball mill is different: the cylinder of the rod mill is a long type, and the floor area is large. The ratio of the length to the diameter of the cylinder is generally 1.5 to 2.0;

The cylinder of the ball mill is a barrel or a cone. And the ratio of the length to the diameter of the cylinder is small, and in most cases the ratio is only slightly larger than 1, and the floor area is small, too.

The above is the main content of this article. The ball mill and the rod mill are the same type of machine on the appearance, but there are still great differences in the interior. It is very necessary to select a suitable machine for the production to optimize the product effect and maximize its efficiency.

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ball mills

ball mills

In all ore dressing and milling Operations, including flotation, cyanidation, gravity concentration, and amalgamation, the Working Principle is to crush and grind, often with rob mill & ball mills, the ore in order to liberate the minerals. In the chemical and process industries, grinding is an important step in preparing raw materials for subsequent treatment.In present day practice, ore is reduced to a size many times finer than can be obtained with crushers. Over a period of many years various fine grinding machines have been developed and used, but the ball mill has become standard due to its simplicity and low operating cost.

A ball millefficiently operated performs a wide variety of services. In small milling plants, where simplicity is most essential, it is not economical to use more than single stage crushing, because the Steel-Head Ball or Rod Mill will take up to 2 feed and grind it to the desired fineness. In larger plants where several stages of coarse and fine crushing are used, it is customary to crush from 1/2 to as fine as 8 mesh.

Many grinding circuits necessitate regrinding of concentrates or middling products to extremely fine sizes to liberate the closely associated minerals from each other. In these cases, the feed to the ball mill may be from 10 to 100 mesh or even finer.

Where the finished product does not have to be uniform, a ball mill may be operated in open circuit, but where the finished product must be uniform it is essential that the grinding mill be used in closed circuit with a screen, if a coarse product is desired, and with a classifier if a fine product is required. In most cases it is desirable to operate the grinding mill in closed circuit with a screen or classifier as higher efficiency and capacity are obtained. Often a mill using steel rods as the grinding medium is recommended, where the product must have the minimum amount of fines (rods give a more nearly uniform product).

Often a problem requires some study to determine the economic fineness to which a product can or should be ground. In this case the 911Equipment Company offers its complete testing service so that accurate grinding mill size may be determined.

Until recently many operators have believed that one particular type of grinding mill had greater efficiency and resulting capacity than some other type. However, it is now commonly agreed and accepted that the work done by any ballmill depends directly upon the power input; the maximum power input into any ball or rod mill depends upon weight of grinding charge, mill speed, and liner design.

The apparent difference in capacities between grinding mills (listed as being the same size) is due to the fact that there is no uniform method of designating the size of a mill, for example: a 5 x 5 Ball Mill has a working diameter of 5 inside the liners and has 20 per cent more capacity than all other ball mills designated as 5 x 5 where the shell is 5 inside diameter and the working diameter is only 48 with the liners in place.

Ball-Rod Mills, based on 4 liners and capacity varying as 2.6 power of mill diameter, on the 5 size give 20 per cent increased capacity; on the 4 size, 25 per cent; and on the 3 size, 28 per cent. This fact should be carefully kept in mind when determining the capacity of a Steel- Head Ball-Rod Mill, as this unit can carry a greater ball or rod charge and has potentially higher capacity in a given size when the full ball or rod charge is carried.

A mill shorter in length may be used if the grinding problem indicates a definite power input. This allows the alternative of greater capacity at a later date or a considerable saving in first cost with a shorter mill, if reserve capacity is not desired. The capacities of Ball-Rod Mills are considerably higher than many other types because the diameters are measured inside the liners.

The correct grinding mill depends so much upon the particular ore being treated and the product desired, that a mill must have maximum flexibility in length, type of grinding medium, type of discharge, and speed.With the Ball-Rod Mill it is possible to build this unit in exact accordance with your requirements, as illustrated.

To best serve your needs, the Trunnion can be furnished with small (standard), medium, or large diameter opening for each type of discharge. The sketch shows diagrammatic arrangements of the four different types of discharge for each size of trunnion opening, and peripheral discharge is described later.

Ball-Rod Mills of the grate discharge type are made by adding the improved type of grates to a standard Ball-Rod Mill. These grates are bolted to the discharge head in much the same manner as the standard headliners.

The grates are of alloy steel and are cast integral with the lifter bars which are essential to the efficient operation of this type of ball or rod mill. These lifter bars have a similar action to a pump:i. e., in lifting the product so as to discharge quickly through the mill trunnion.

These Discharge Grates also incorporate as an integral part, a liner between the lifters and steel head of the ball mill to prevent wear of the mill head. By combining these parts into a single casting, repairs and maintenance are greatly simplified. The center of the grate discharge end of this mill is open to permit adding of balls or for adding water to the mill through the discharge end.

Instead of being constructed of bars cast into a frame, Grates are cast entire and have cored holes which widen toward the outside of the mill similar to the taper in grizzly bars. The grate type discharge is illustrated.

The peripheral discharge type of Ball-Rod Mill is a modification of the grate type, and is recommended where a free gravity discharge is desired. It is particularly applicable when production of too many fine particles is detrimental and a quick pass through the mill is desired, and for dry grinding.

The drawings show the arrangement of the peripheral discharge. The discharge consists of openings in the shell into which bushings with holes of the desired size are inserted. On the outside of the mill, flanges are used to attach a stationary discharge hopper to prevent pulp splash or too much dust.

The mill may be operated either as a peripheral discharge or a combination or peripheral and trunnion discharge unit, depending on the desired operating conditions. If at any time the peripheral discharge is undesirable, plugs inserted into the bushings will convert the mill to a trunnion discharge type mill.

Unless otherwise specified, a hard iron liner is furnished. This liner is made of the best grade white iron and is most serviceable for the smaller size mills where large balls are not used. Hard iron liners have a much lower first cost.

Electric steel, although more expensive than hard iron, has advantage of minimum breakage and allows final wear to thinner section. Steel liners are recommended when the mills are for export or where the source of liner replacement is at a considerable distance.

Molychrome steel has longer wearing qualities and greater strength than hard iron. Breakage is not so apt to occur during shipment, and any size ball can be charged into a mill equipped with molychrome liners.

Manganese liners for Ball-Rod Mills are the world famous AMSCO Brand, and are the best obtainable. The first cost is the highest, but in most cases the cost per ton of ore ground is the lowest. These liners contain 12 to 14% manganese.

The feed and discharge trunnions are provided with cast iron or white iron throat liners. As these parts are not subjected to impact and must only withstand abrasion, alloys are not commonly used but can be supplied.

Gears for Ball-Rod Mills drives are furnished as standard on the discharge end of the mill where they are out of the way of the classifier return, scoop feeder, or original feed. Due to convertible type construction the mills can be furnished with gears on the feed end. Gear drives are available in two alternative combinations, which are:

All pinions are properly bored, key-seated, and pressed onto the steel countershaft, which is oversize and properly keyseated for the pinion and drive pulleys or sheaves. The countershaft operates on high grade, heavy duty, nickel babbitt bearings.

Any type of drive can be furnished for Ball-Rod Mills in accordance with your requirements. Belt drives are available with pulleys either plain or equipped with friction clutch. Various V- Rope combinations can also be supplied.

The most economical drive to use up to 50 H. P., is a high starting torque motor connected to the pinion shaft by means of a flat or V-Rope drive. For larger size motors the wound rotor (slip ring) is recommended due to its low current requirement in starting up the ball mill.

Should you be operating your own power plant or have D. C. current, please specify so that there will be no confusion as to motor characteristics. If switches are to be supplied, exact voltage to be used should be given.

Even though many ores require fine grinding for maximum recovery, most ores liberate a large percentage of the minerals during the first pass through the grinding unit. Thus, if the free minerals can be immediately removed from the ball mill classifier circuit, there is little chance for overgrinding.

This is actually what has happened wherever Mineral Jigs or Unit Flotation Cells have been installed in the ball mill classifier circuit. With the installation of one or both of these machines between the ball mill and classifier, as high as 70 per cent of the free gold and sulphide minerals can be immediately removed, thus reducing grinding costs and improving over-all recovery. The advantage of this method lies in the fact that heavy and usually valuable minerals, which otherwise would be ground finer because of their faster settling in the classifier and consequent return to the grinding mill, are removed from the circuit as soon as freed. This applies particularly to gold and lead ores.

Ball-Rod Mills have heavy rolled steel plate shells which are arc welded inside and outside to the steel heads or to rolled steel flanges, depending upon the type of mill. The double welding not only gives increased structural strength, but eliminates any possibility of leakage.

Where a single or double flanged shell is used, the faces are accurately machined and drilled to template to insure perfect fit and alignment with the holes in the head. These flanges are machined with male and female joints which take the shearing stresses off the bolts.

The Ball-Rod Mill Heads are oversize in section, heavily ribbed and are cast from electric furnace steel which has a strength of approximately four times that of cast iron. The head and trunnion bearings are designed to support a mill with length double its diameter. This extra strength, besides eliminating the possibility of head breakage or other structural failure (either while in transit or while in service), imparts to Ball-Rod Mills a flexibility heretofore lacking in grinding mills. Also, for instance, if you have a 5 x 5 mill, you can add another 5 shell length and thus get double the original capacity; or any length required up to a maximum of 12 total length.

On Type A mills the steel heads are double welded to the rolled steel shell. On type B and other flanged type mills the heads are machined with male and female joints to match the shell flanges, thus taking the shearing stresses from the heavy machine bolts which connect the shell flanges to the heads.

The manhole cover is protected from wear by heavy liners. An extended lip is provided for loosening the door with a crow-bar, and lifting handles are also provided. The manhole door is furnished with suitable gaskets to prevent leakage.

The mill trunnions are carried on heavy babbitt bearings which provide ample surface to insure low bearing pressure. If at any time the normal length is doubled to obtain increased capacity, these large trunnion bearings will easily support the additional load. Trunnion bearings are of the rigid type, as the perfect alignment of the trunnion surface on Ball-Rod Mills eliminates any need for the more expensive self-aligning type of bearing.

The cap on the upper half of the trunnion bearing is provided with a shroud which extends over the drip flange of the trunnion and effectively prevents the entrance of dirt or grit. The bearing has a large space for wool waste and lubricant and this is easily accessible through a large opening which is covered to prevent dirt from getting into the bearing.Ball and socket bearings can be furnished.

Scoop Feeders for Ball-Rod Mills are made in various radius sizes. Standard scoops are made of cast iron and for the 3 size a 13 or 19 feeder is supplied, for the 4 size a 30 or 36, for the 5 a 36 or 42, and for the 6 a 42 or 48 feeder. Welded steel scoop feeders can, however, be supplied in any radius.

The correct size of feeder depends upon the size of the classifier, and the smallest feeder should be used which will permit gravity flow for closed circuit grinding between classifier and the ball or rod mill. All feeders are built with a removable wearing lip which can be easily replaced and are designed to give minimum scoop wear.

A combination drum and scoop feeder can be supplied if necessary. This feeder is made of heavy steel plate and strongly welded. These drum-scoop feeders are available in the same sizes as the cast iron feeders but can be built in any radius. Scoop liners can be furnished.

The trunnions on Ball-Rod Mills are flanged and carefully machined so that scoops are held in place by large machine bolts and not cap screws or stud bolts. The feed trunnion flange is machined with a shoulder for insuring a proper fit for the feed scoop, and the weight of the scoop is carried on this shoulder so that all strain is removed from the bolts which hold the scoop.

High carbon steel rods are recommended, hot rolled, hot sawed or sheared, to a length of 2 less than actual length of mill taken inside the liners. The initial rod charge is generally a mixture ranging from 1.5 to 3 in diameter. During operation, rod make-up is generally the maximum size. The weights per lineal foot of rods of various diameters are approximately: 1.5 to 6 lbs.; 2-10.7 lbs.; 2.5-16.7 lbs.; and 3-24 lbs.

Forged from the best high carbon manganese steel, they are of the finest quality which can be produced and give long, satisfactory service. Data on ball charges for Ball-Rod Mills are listed in Table 5. Further information regarding grinding balls is included in Table 6.

Rod Mills has a very define and narrow discharge product size range. Feeding a Rod Mill finer rocks will greatly impact its tonnage while not significantly affect its discharge product sizes. The 3.5 diameter rod of a mill, can only grind so fine.

Crushers are well understood by most. Rod and Ball Mills not so much however as their size reduction actions are hidden in the tube (mill). As for Rod Mills, the image above best expresses what is going on inside. As rocks is feed into the mill, they are crushed (pinched) by the weight of its 3.5 x 16 rods at one end while the smaller particles migrate towards the discharge end and get slightly abraded (as in a Ball Mill) on the way there.

We haveSmall Ball Mills for sale coming in at very good prices. These ball mills are relatively small, bearing mounted on a steel frame. All ball mills are sold with motor, gears, steel liners and optional grinding media charge/load.

Ball Mills or Rod Mills in a complete range of sizes up to 10 diameter x20 long, offer features of operation and convertibility to meet your exactneeds. They may be used for pulverizing and either wet or dry grindingsystems. Mills are available in both light-duty and heavy-duty constructionto meet your specific requirements.

All Mills feature electric cast steel heads and heavy rolled steelplate shells. Self-aligning main trunnion bearings on large mills are sealedand internally flood-lubricated. Replaceable mill trunnions. Pinion shaftbearings are self-aligning, roller bearing type, enclosed in dust-tightcarrier. Adjustable, single-unit soleplate under trunnion and drive pinionsfor perfect, permanent gear alignment.

Ball Mills can be supplied with either ceramic or rubber linings for wet or dry grinding, for continuous or batch type operation, in sizes from 15 x 21 to 8 x 12. High density ceramic linings of uniform hardness male possible thinner linings and greater and more effective grinding volume. Mills are shipped with liners installed.

Complete laboratory testing service, mill and air classifier engineering and proven equipment make possible a single source for your complete dry-grinding mill installation. Units available with air swept design and centrifugal classifiers or with elevators and mechanical type air classifiers. All sizes and capacities of units. Laboratory-size air classifier also available.

A special purpose batch mill designed especially for grinding and mixing involving acids and corrosive materials. No corners mean easy cleaning and choice of rubber or ceramic linings make it corrosion resistant. Shape of mill and ball segregation gives preferential grinding action for grinding and mixing of pigments and catalysts. Made in 2, 3 and 4 diameter grinding drums.

Nowadays grinding mills are almost extensively used for comminution of materials ranging from 5 mm to 40 mm (3/161 5/8) down to varying product sizes. They have vast applications within different branches of industry such as for example the ore dressing, cement, lime, porcelain and chemical industries and can be designed for continuous as well as batch grinding.

Ball mills can be used for coarse grinding as described for the rod mill. They will, however, in that application produce more fines and tramp oversize and will in any case necessitate installation of effective classification.If finer grinding is wanted two or three stage grinding is advisable as for instant primary rod mill with 75100 mm (34) rods, secondary ball mill with 2540 mm(11) balls and possibly tertiary ball mill with 20 mm () balls or cylpebs.To obtain a close size distribution in the fine range the specific surface of the grinding media should be as high as possible. Thus as small balls as possible should be used in each stage.

The principal field of rod mill usage is the preparation of products in the 5 mm0.4 mm (4 mesh to 35 mesh) range. It may sometimes be recommended also for finer grinding. Within these limits a rod mill is usually superior to and more efficient than a ball mill. The basic principle for rod grinding is reduction by line contact between rods extending the full length of the mill, resulting in selective grinding carried out on the largest particle sizes. This results in a minimum production of extreme fines or slimes and more effective grinding work as compared with a ball mill. One stage rod mill grinding is therefore suitable for preparation of feed to gravimetric ore dressing methods, certain flotation processes with slime problems and magnetic cobbing. Rod mills are frequently used as primary mills to produce suitable feed to the second grinding stage. Rod mills have usually a length/diameter ratio of at least 1.4.

Tube mills are in principle to be considered as ball mills, the basic difference being that the length/diameter ratio is greater (35). They are commonly used for surface cleaning or scrubbing action and fine grinding in open circuit.

In some cases it is suitable to use screened fractions of the material as grinding media. Such mills are usually called pebble mills, but the working principle is the same as for ball mills. As the power input is approximately directly proportional to the volume weight of the grinding media, the power input for pebble mills is correspondingly smaller than for a ball mill.

A dry process requires usually dry grinding. If the feed is wet and sticky, it is often necessary to lower the moisture content below 1 %. Grinding in front of wet processes can be done wet or dry. In dry grinding the energy consumption is higher, but the wear of linings and charge is less than for wet grinding, especially when treating highly abrasive and corrosive material. When comparing the economy of wet and dry grinding, the different costs for the entire process must be considered.

An increase in the mill speed will give a directly proportional increase in mill power but there seems to be a square proportional increase in the wear. Rod mills generally operate within the range of 6075 % of critical speed in order to avoid excessive wear and tangled rods. Ball and pebble mills are usually operated at 7085 % of critical speed. For dry grinding the speed is usually somewhat lower.

The mill lining can be made of rubber or different types of steel (manganese or Ni-hard) with liner types according to the customers requirements. For special applications we can also supply porcelain, basalt and other linings.

The mill power is approximately directly proportional to the charge volume within the normal range. When calculating a mill 40 % charge volume is generally used. In pebble and ball mills quite often charge volumes close to 50 % are used. In a pebble mill the pebble consumption ranges from 315 % and the charge has to be controlled automatically to maintain uniform power consumption.

In all cases the net energy consumption per ton (kWh/ton) must be known either from previous experience or laboratory tests before mill size can be determined. The required mill net power P kW ( = ton/hX kWh/ton) is obtained from

Trunnions of S.G. iron or steel castings with machined flange and bearing seat incl. device for dismantling the bearings. For smaller mills the heads and trunnions are sometimes made in grey cast iron.

The mills can be used either for dry or wet, rod or ball grinding. By using a separate attachment the discharge end can be changed so that the mills can be used for peripheral instead of overflow discharge.

ball mill - an overview | sciencedirect topics

ball mill - an overview | sciencedirect topics

The ball mill accepts the SAG or AG mill product. Ball mills give a controlled final grind and produce flotation feed of a uniform size. Ball mills tumble iron or steel balls with the ore. The balls are initially 510 cm diameter but gradually wear away as grinding of the ore proceeds. The feed to ball mills (dry basis) is typically 75 vol.-% ore and 25% steel.

The ball mill is operated in closed circuit with a particle-size measurement device and size-control cyclones. The cyclones send correct-size material on to flotation and direct oversize material back to the ball mill for further grinding.

Grinding elements in ball mills travel at different velocities. Therefore, collision force, direction and kinetic energy between two or more elements vary greatly within the ball charge. Frictional wear or rubbing forces act on the particles, as well as collision energy. These forces are derived from the rotational motion of the balls and movement of particles within the mill and contact zones of colliding balls.

By rotation of the mill body, due to friction between mill wall and balls, the latter rise in the direction of rotation till a helix angle does not exceed the angle of repose, whereupon, the balls roll down. Increasing of rotation rate leads to growth of the centrifugal force and the helix angle increases, correspondingly, till the component of weight strength of balls become larger than the centrifugal force. From this moment the balls are beginning to fall down, describing during falling certain parabolic curves (Figure 2.7). With the further increase of rotation rate, the centrifugal force may become so large that balls will turn together with the mill body without falling down. The critical speed n (rpm) when the balls are attached to the wall due to centrifugation:

where Dm is the mill diameter in meters. The optimum rotational speed is usually set at 6580% of the critical speed. These data are approximate and may not be valid for metal particles that tend to agglomerate by welding.

The degree of filling the mill with balls also influences productivity of the mill and milling efficiency. With excessive filling, the rising balls collide with falling ones. Generally, filling the mill by balls must not exceed 3035% of its volume.

The mill productivity also depends on many other factors: physical-chemical properties of feed material, filling of the mill by balls and their sizes, armor surface shape, speed of rotation, milling fineness and timely moving off of ground product.

where b.ap is the apparent density of the balls; l is the degree of filling of the mill by balls; n is revolutions per minute; 1, and 2 are coefficients of efficiency of electric engine and drive, respectively.

A feature of ball mills is their high specific energy consumption; a mill filled with balls, working idle, consumes approximately as much energy as at full-scale capacity, i.e. during grinding of material. Therefore, it is most disadvantageous to use a ball mill at less than full capacity.

The ball mill is a tumbling mill that uses steel balls as the grinding media. The length of the cylindrical shell is usually 11.5 times the shell diameter (Figure 8.11). The feed can be dry, with less than 3% moisture to minimize ball coating, or slurry containing 2040% water by weight. Ball mills are employed in either primary or secondary grinding applications. In primary applications, they receive their feed from crushers, and in secondary applications, they receive their feed from rod mills, AG mills, or SAG mills.

Ball mills are filled up to 40% with steel balls (with 3080mm diameter), which effectively grind the ore. The material that is to be ground fills the voids between the balls. The tumbling balls capture the particles in ball/ball or ball/liner events and load them to the point of fracture.

When hard pebbles rather than steel balls are used for the grinding media, the mills are known as pebble mills. As mentioned earlier, pebble mills are widely used in the North American taconite iron ore operations. Since the weight of pebbles per unit volume is 3555% of that of steel balls, and as the power input is directly proportional to the volume weight of the grinding medium, the power input and capacity of pebble mills are correspondingly lower. Thus, in a given grinding circuit, for a certain feed rate, a pebble mill would be much larger than a ball mill, with correspondingly a higher capital cost. However, the increase in capital cost is justified economically by a reduction in operating cost attributed to the elimination of steel grinding media.

In general, ball mills can be operated either wet or dry and are capable of producing products in the order of 100m. This represents reduction ratios of as great as 100. Very large tonnages can be ground with these ball mills because they are very effective material handling devices. Ball mills are rated by power rather than capacity. Today, the largest ball mill in operation is 8.53m diameter and 13.41m long with a corresponding motor power of 22MW (Toromocho, private communications).

Planetary ball mills. A planetary ball mill consists of at least one grinding jar, which is arranged eccentrically on a so-called sun wheel. The direction of movement of the sun wheel is opposite to that of the grinding jars according to a fixed ratio. The grinding balls in the grinding jars are subjected to superimposed rotational movements. The jars are moved around their own axis and, in the opposite direction, around the axis of the sun wheel at uniform speed and uniform rotation ratios. The result is that the superimposition of the centrifugal forces changes constantly (Coriolis motion). The grinding balls describe a semicircular movement, separate from the inside wall, and collide with the opposite surface at high impact energy. The difference in speeds produces an interaction between frictional and impact forces, which releases high dynamic energies. The interplay between these forces produces the high and very effective degree of size reduction of the planetary ball mill. Planetary ball mills are smaller than common ball mills, and are mainly used in laboratories for grinding sample material down to very small sizes.

Vibration mill. Twin- and three-tube vibrating mills are driven by an unbalanced drive. The entire filling of the grinding cylinders, which comprises the grinding media and the feed material, constantly receives impulses from the circular vibrations in the body of the mill. The grinding action itself is produced by the rotation of the grinding media in the opposite direction to the driving rotation and by continuous head-on collisions of the grinding media. The residence time of the material contained in the grinding cylinders is determined by the quantity of the flowing material. The residence time can also be influenced by using damming devices. The sample passes through the grinding cylinders in a helical curve and slides down from the inflow to the outflow. The high degree of fineness achieved is the result of this long grinding procedure. Continuous feeding is carried out by vibrating feeders, rotary valves, or conveyor screws. The product is subsequently conveyed either pneumatically or mechanically. They are basically used to homogenize food and feed.

CryoGrinder. As small samples (100 mg or <20 ml) are difficult to recover from a standard mortar and pestle, the CryoGrinder serves as an alternative. The CryoGrinder is a miniature mortar shaped as a small well and a tightly fitting pestle. The CryoGrinder is prechilled, then samples are added to the well and ground by a handheld cordless screwdriver. The homogenization and collection of the sample is highly efficient. In environmental analysis, this system is used when very small samples are available, such as small organisms or organs (brains, hepatopancreas, etc.).

The vibratory ball mill is another kind of high-energy ball mill that is used mainly for preparing amorphous alloys. The vials capacities in the vibratory mills are smaller (about 10 ml in volume) compared to the previous types of mills. In this mill, the charge of the powder and milling tools are agitated in three perpendicular directions (Fig. 1.6) at very high speed, as high as 1200 rpm.

Another type of the vibratory ball mill, which is used at the van der Waals-Zeeman Laboratory, consists of a stainless steel vial with a hardened steel bottom, and a single hardened steel ball of 6 cm in diameter (Fig. 1.7).

The mill is evacuated during milling to a pressure of 106 Torr, in order to avoid reactions with a gas atmosphere.[44] Subsequently, this mill is suitable for mechanical alloying of some special systems that are highly reactive with the surrounding atmosphere, such as rare earth elements.

A ball mill is a relatively simple apparatus in which the motion of the reactor, or of a part of it, induces a series of collisions of balls with each other and with the reactor walls (Suryanarayana, 2001). At each collision, a fraction of the powder inside the reactor is trapped between the colliding surfaces of the milling tools and submitted to a mechanical load at relatively high strain rates (Suryanarayana, 2001). This load generates a local nonhydrostatic mechanical stress at every point of contact between any pair of powder particles. The specific features of the deformation processes induced by these stresses depend on the intensity of the mechanical stresses themselves, on the details of the powder particle arrangement, that is on the topology of the contact network, and on the physical and chemical properties of powders (Martin et al., 2003; Delogu, 2008a). At the end of any given collision event, the powder that has been trapped is remixed with the powder that has not undergone this process. Correspondingly, at any instant in the mechanical processing, the whole powder charge includes fractions of powder that have undergone a different number of collisions.

The individual reactive processes at the perturbed interface between metallic elements are expected to occur on timescales that are, at most, comparable with the collision duration (Hammerberg et al., 1998; Urakaev and Boldyrev, 2000; Lund and Schuh, 2003; Delogu and Cocco, 2005a,b). Therefore, unless the ball mill is characterized by unusually high rates of powder mixing and frequency of collisions, reactive events initiated by local deformation processes at a given collision are not affected by a successive collision. Indeed, the time interval between successive collisions is significantly longer than the time period required by local structural perturbations for full relaxation (Hammerberg et al., 1998; Urakaev and Boldyrev, 2000; Lund and Schuh, 2003; Delogu and Cocco, 2005a,b).

These few considerations suffice to point out the two fundamental features of powder processing by ball milling, which in turn govern the MA processes in ball mills. First, mechanical processing by ball milling is a discrete processing method. Second, it has statistical character. All of this has important consequences for the study of the kinetics of MA processes. The fact that local deformation events are connected to individual collisions suggests that absolute time is not an appropriate reference quantity to describe mechanically induced phase transformations. Such a description should rather be made as a function of the number of collisions (Delogu et al., 2004). A satisfactory description of the MA kinetics must also account for the intrinsic statistical character of powder processing by ball milling. The amount of powder trapped in any given collision, at the end of collision is indeed substantially remixed with the other powder in the reactor. It follows that the same amount, or a fraction of it, could at least in principle be trapped again in the successive collision.

This is undoubtedly a difficult aspect to take into account in a mathematical description of MA kinetics. There are at least two extreme cases to consider. On the one hand, it could be assumed that the powder trapped in a given collision cannot be trapped in the successive one. On the other, it could be assumed that powder mixing is ideal and that the amount of powder trapped at a given collision has the same probability of being processed in the successive collision. Both these cases allow the development of a mathematical model able to describe the relationship between apparent kinetics and individual collision events. However, the latter assumption seems to be more reliable than the former one, at least for commercial mills characterized by relatively complex displacement in the reactor (Manai et al., 2001, 2004).

A further obvious condition for the successful development of a mathematical description of MA processes is the one related to the uniformity of collision regimes. More specifically, it is highly desirable that the powders trapped at impact always experience the same conditions. This requires the control of the ball dynamics inside the reactor, which can be approximately obtained by using a single milling ball and an amount of powder large enough to assure inelastic impact conditions (Manai et al., 2001, 2004; Delogu et al., 2004). In fact, the use of a single milling ball avoids impacts between balls, which have a remarkable disordering effect on the ball dynamics, whereas inelastic impact conditions permit the establishment of regular and periodic ball dynamics (Manai et al., 2001, 2004; Delogu et al., 2004).

All of the above assumptions and observations represent the basis and guidelines for the development of the mathematical model briefly outlined in the following. It has been successfully applied to the case of a Spex Mixer/ Mill mod. 8000, but the same approach can, in principle, be used for other ball mills.

The Planetary ball mills are the most popular mills used in MM, MA, and MD scientific researches for synthesizing almost all of the materials presented in Figure 1.1. In this type of mill, the milling media have considerably high energy, because milling stock and balls come off the inner wall of the vial (milling bowl or vial) and the effective centrifugal force reaches up to 20 times gravitational acceleration.

The centrifugal forces caused by the rotation of the supporting disc and autonomous turning of the vial act on the milling charge (balls and powders). Since the turning directions of the supporting disc and the vial are opposite, the centrifugal forces alternately are synchronized and opposite. Therefore, the milling media and the charged powders alternatively roll on the inner wall of the vial, and are lifted and thrown off across the bowl at high speed, as schematically presented in Figure 2.17.

However, there are some companies in the world who manufacture and sell number of planetary-type ball mills; Fritsch GmbH (www.fritsch-milling.com) and Retsch (http://www.retsch.com) are considered to be the oldest and principal companies in this area.

Fritsch produces different types of planetary ball mills with different capacities and rotation speeds. Perhaps, Fritsch Pulverisette P5 (Figure 2.18(a)) and Fritsch Pulverisette P6 (Figure 2.18(b)) are the most popular models of Fritsch planetary ball mills. A variety of vials and balls made of different materials with different capacities, starting from 80ml up to 500ml, are available for the Fritsch Pulverisette planetary ball mills; these include tempered steel, stainless steel, tungsten carbide, agate, sintered corundum, silicon nitride, and zirconium oxide. Figure 2.19 presents 80ml-tempered steel vial (a) and 500ml-agate vials (b) together with their milling media that are made of the same materials.

Figure 2.18. Photographs of Fritsch planetary-type high-energy ball mill of (a) Pulverisette P5 and (b) Pulverisette P6. The equipment is housed in the Nanotechnology Laboratory, Energy and Building Research Center (EBRC), Kuwait Institute for Scientific Research (KISR).

Figure 2.19. Photographs of the vials used for Fritsch planetary ball mills with capacity of (a) 80ml and (b) 500ml. The vials and the balls shown in (a) and (b) are made of tempered steel agate materials, respectively (Nanotechnology Laboratory, Energy and Building Research Center (EBRC), Kuwait Institute for Scientific Research (KISR)).

More recently and in year 2011, Fritsch GmbH (http://www.fritsch-milling.com) introduced a new high-speed and versatile planetary ball mill called Planetary Micro Mill PULVERISETTE 7 (Figure 2.20). The company claims this new ball mill will be helpful to enable extreme high-energy ball milling at rotational speed reaching to 1,100rpm. This allows the new mill to achieve sensational centrifugal accelerations up to 95 times Earth gravity. They also mentioned that the energy application resulted from this new machine is about 150% greater than the classic planetary mills. Accordingly, it is expected that this new milling machine will enable the researchers to get their milled powders in short ball-milling time with fine powder particle sizes that can reach to be less than 1m in diameter. The vials available for this new type of mill have sizes of 20, 45, and 80ml. Both the vials and balls can be made of the same materials, which are used in the manufacture of large vials used for the classic Fritsch planetary ball mills, as shown in the previous text.

Retsch has also produced a number of capable high-energy planetary ball mills with different capacities (http://www.retsch.com/products/milling/planetary-ball-mills/); namely Planetary Ball Mill PM 100 (Figure 2.21(a)), Planetary Ball Mill PM 100 CM, Planetary Ball Mill PM 200, and Planetary Ball Mill PM 400 (Figure 2.21(b)). Like Fritsch, Retsch offers high-quality ball-milling vials with different capacities (12, 25, 50, 50, 125, 250, and 500ml) and balls of different diameters (540mm), as exemplified in Figure 2.22. These milling tools can be made of hardened steel as well as other different materials such as carbides, nitrides, and oxides.

Figure 2.21. Photographs of Retsch planetary-type high-energy ball mill of (a) PM 100 and (b) PM 400. The equipment is housed in the Nanotechnology Laboratory, Energy and Building Research Center (EBRC), Kuwait Institute for Scientific Research (KISR).

Figure 2.22. Photographs of the vials used for Retsch planetary ball mills with capacity of (a) 80ml, (b) 250ml, and (c) 500ml. The vials and the balls shown are made of tempered steel (Nanotechnology Laboratory, Energy and Building Research Center (EBRC), Kuwait Institute for Scientific Research (KISR)).

Both Fritsch and Retsch companies have offered special types of vials that allow monitoring and measure the gas pressure and temperature inside the vial during the high-energy planetary ball-milling process. Moreover, these vials allow milling the powders under inert (e.g., argon or helium) or reactive gas (e.g., hydrogen or nitrogen) with a maximum gas pressure of 500kPa (5bar). It is worth mentioning here that such a development made on the vials design allows the users and researchers to monitor the progress tackled during the MA and MD processes by following up the phase transformations and heat realizing upon RBM, where the interaction of the gas used with the freshly created surfaces of the powders during milling (adsorption, absorption, desorption, and decomposition) can be monitored. Furthermore, the data of the temperature and pressure driven upon using this system is very helpful when the ball mills are used for the formation of stable (e.g., intermetallic compounds) and metastable (e.g., amorphous and nanocrystalline materials) phases. In addition, measuring the vial temperature during blank (without samples) high-energy ball mill can be used as an indication to realize the effects of friction, impact, and conversion processes.

More recently, Evico-magnetics (www.evico-magnetics.de) has manufactured an extraordinary high-pressure milling vial with gas-temperature-monitoring (GTM) system. Likewise both system produced by Fritsch and Retsch, the developed system produced by Evico-magnetics, allowing RBM but at very high gas pressure that can reach to 15,000kPa (150bar). In addition, it allows in situ monitoring of temperature and of pressure by incorporating GTM. The vials, which can be used with any planetary mills, are made of hardened steel with capacity up to 220ml. The manufacturer offers also two-channel system for simultaneous use of two milling vials.

Using different ball mills as examples, it has been shown that, on the basis of the theory of glancing collision of rigid bodies, the theoretical calculation of tPT conditions and the kinetics of mechanochemical processes are possible for the reactors that are intended to perform different physicochemical processes during mechanical treatment of solids. According to the calculations, the physicochemical effect of mechanochemical reactors is due to short-time impulses of pressure (P = ~ 10101011 dyn cm2) with shift, and temperature T(x, t). The highest temperature impulse T ~ 103 K are caused by the dry friction phenomenon.

Typical spatial and time parameters of the impactfriction interaction of the particles with a size R ~ 104 cm are as follows: localization region, x ~ 106 cm; time, t ~ 108 s. On the basis of the obtained theoretical results, the effect of short-time contact fusion of particles treated in various comminuting devices can play a key role in the mechanism of activation and chemical reactions for wide range of mechanochemical processes. This role involves several aspects, that is, the very fact of contact fusion transforms the solid phase process onto another qualitative level, judging from the mass transfer coefficients. The spatial and time characteristics of the fused zone are such that quenching of non-equilibrium defects and intermediate products of chemical reactions occurs; solidification of the fused zone near the contact point results in the formation of a nanocrystal or nanoamor- phous state. The calculation models considered above and the kinetic equations obtained using them allow quantitative ab initio estimates of rate constants to be performed for any specific processes of mechanical activation and chemical transformation of the substances in ball mills.

There are two classes of ball mills: planetary and mixer (also called swing) mill. The terms high-speed vibration milling (HSVM), high-speed ball milling (HSBM), and planetary ball mill (PBM) are often used. The commercial apparatus are PBMs Fritsch P-5 and Fritsch Pulverisettes 6 and 7 classic line, the Retsch shaker (or mixer) mills ZM1, MM200, MM400, AS200, the Spex 8000, 6750 freezer/mill SPEX CertiPrep, and the SWH-0.4 vibrational ball mill. In some instances temperature controlled apparatus were used (58MI1); freezer/mills were used in some rare cases (13MOP1824).

The balls are made of stainless steel, agate (SiO2), zirconium oxide (ZrO2), or silicon nitride (Si3N). The use of stainless steel will contaminate the samples with steel particles and this is a problem both for solid-state NMR and for drug purity.

However, there are many types of ball mills (see Chapter 2 for more details), such as drum ball mills, jet ball mills, bead-mills, roller ball mills, vibration ball mills, and planetary ball mills, they can be grouped or classified into two types according to their rotation speed, as follows: (i) high-energy ball mills and (ii) low-energy ball mills. Table 3.1 presents characteristics and comparison between three types of ball mills (attritors, vibratory mills, planetary ball mills and roller mills) that are intensively used on MA, MD, and MM techniques.

In fact, choosing the right ball mill depends on the objectives of the process and the sort of materials (hard, brittle, ductile, etc.) that will be subjecting to the ball-milling process. For example, the characteristics and properties of those ball mills used for reduction in the particle size of the starting materials via top-down approach, or so-called mechanical milling (MM process), or for mechanically induced solid-state mixing for fabrications of composite and nanocomposite powders may differ widely from those mills used for achieving mechanically induced solid-state reaction (MISSR) between the starting reactant materials of elemental powders (MA process), or for tackling dramatic phase transformation changes on the structure of the starting materials (MD). Most of the ball mills in the market can be employed for different purposes and for preparing of wide range of new materials.

Martinez-Sanchez et al. [4] have pointed out that employing of high-energy ball mills not only contaminates the milled amorphous powders with significant volume fractions of impurities that come from milling media that move at high velocity, but it also affects the stability and crystallization properties of the formed amorphous phase. They have proved that the properties of the formed amorphous phase (Mo53Ni47) powder depends on the type of the ball-mill equipment (SPEX 8000D Mixer/Mill and Zoz Simoloter mill) used in their important investigations. This was indicated by the high contamination content of oxygen on the amorphous powders prepared by SPEX 8000D Mixer/Mill, when compared with the corresponding amorphous powders prepared by Zoz Simoloter mill. Accordingly, they have attributed the poor stabilities, indexed by the crystallization temperature of the amorphous phase formed by SPEX 8000D Mixer/Mill to the presence of foreign matter (impurities).

ball milling - an overview | sciencedirect topics

ball milling - an overview | sciencedirect topics

Ball milling is often used not only for grinding powders but also for oxides or nanocomposite synthesis and/or structure/phase composition optimization [14,41]. Mechanical activation by ball milling is known to increase the material reactivity and uniformity of spatial distribution of elements [63]. Thus, postsynthesis processing of the materials by ball milling can help with the problem of minor admixture forming during cooling under air after high-temperature sintering due to phase instability.

Ball milling technique, using mechanical alloying and mechanical milling approaches were proposed to the word wide in the 8th decade of the last century for preparing a wide spectrum of powder materials and their alloys. In fact, ball milling process is not new and dates back to more than 150 years. It has been used in size comminutions of ore, mineral dressing, preparing talc powders and many other applications. It might be interesting for us to have a look at the history and development of ball milling and the corresponding products. The photo shows the STEM-BF image of a Cu-based alloy nanoparticle prepared by mechanical alloying (After El-Eskandarany, unpublished work, 2014).

Ball milling, a shear-force dominant process where the particle size goes on reducing by impact and attrition mainly consists of metallic balls (generally Zirconia (ZrO2) or steel balls), acting as grinding media and rotating shell to create centrifugal force. In this process, graphite (precursor) was breakdown by randomly striking with grinding media in the rotating shell to create shear and compression force which helps to overcome the weak Vander Waal's interaction between the graphite layers and results in their splintering. Fig. 4A schematic illustrates ball milling process for graphene preparation. Initially, because of large size of graphite, compressive force dominates and as the graphite gets fragmented, shear force cleaves graphite to produce graphene. However, excessive compression force may damage the crystalline properties of graphene and hence needs to be minimized by controlling the milling parameters e.g. milling duration, milling revolution per minute (rpm), ball-to-graphite/powder ratio (B/P), initial graphite weight, ball diameter. High quality graphene can be achieved under low milling speed; though it will increase the processing time which is highly undesirable for large scale production.

Fig. 4. (A) Schematic illustration of graphene preparation via ball milling. SEM images of bulk graphite (B), GSs/E-H (C) GSs/K (D); (E) and (F) are the respective TEM images; (G) Raman spectra of bulk graphite versus GSs exfoliated via wet milling in E-H and K.

Milling of graphite layers can be instigated in two states: (i) dry ball milling (DBM) and (ii) wet ball milling (WBM). WBM process requires surfactant/solvent such as N,N Dimethylformamide (DMF) [22], N-methylpyrrolidone (NMP) [26], deionized (DI) water [27], potassium acetate [28], 2-ethylhexanol (E-H) [29] and kerosene (K) [29] etc. and is comparatively simpler as compared with DBM. Fig. 4BD show the scanning electron microscopy (SEM) images of bulk graphite, graphene sheets (GSs) prepared in E-H (GSs/E-H) and K (GSs/K), respectively; the corresponding transmission electron microscopy (TEM) images and the Raman spectra are shown in Fig. 4EG, respectively [29].

Compared to this, DBM requires several milling agents e.g. sodium chloride (NaCl) [30], Melamine (Na2SO4) [31,32] etc., along with the metal balls to reduce the stress induced in graphite microstructures, and hence require additional purification for exfoliant's removal. Na2SO4 can be easily washed away by hot water [19] while ammonia-borane (NH3BH3), another exfoliant used to weaken the Vander Waal's bonding between graphite layers can be using ethanol [33]. Table 1 list few ball milling processes carried out using various milling agent (in case of DBM) and solvents (WBM) under different milling conditions.

Ball milling of graphite with appropriate stabilizers is another mode of exfoliation in liquid phase.21 Graphite is ground under high sheer rates with millimeter-sized metal balls causing exfoliation to graphene (Fig. 2.5), under wet or dry conditions. For instance, this method can be employed to produce nearly 50g of graphene in the absence of any oxidant.22 Graphite (50g) was ground in the ball mill with oxalic acid (20g) in this method for 20 hours, but, the separation of unexfoliated fraction was not discussed.22 Similarly, solvent-free graphite exfoliations were carried out under dry milling conditions using KOH,23 ammonia borane,24 and so on. The list of graphite exfoliations performed using ball milling is given in Table 2.2. However, the metallic impurities from the machinery used for ball milling are a major disadvantage of this method for certain applications.25

Reactive ball-milling (RBM) technique has been considered as a powerful tool for fabrication of metallic nitrides and hydrides via room temperature ball milling. The flowchart shows the mechanism of gas-solid reaction through RBM that was proposed by El-Eskandarany. In his model, the starting metallic powders are subjected to dramatic shear and impact forces that are generated by the ball-milling media. The powders are, therefore, disintegrated into smaller particles, and very clean or fresh oxygen-free active surfaces of the powders are created. The reactive milling atmosphere (nitrogen or hydrogen gases) was gettered and absorbed completely by the first atomically clean surfaces of the metallic ball-milled powders to react in a same manner as a gas-solid reaction owing to the mechanically induced reactive milling.

Ball milling is a grinding method that grinds nanotubes into extremely fine powders. During the ball milling process, the collision between the tiny rigid balls in a concealed container will generate localized high pressure. Usually, ceramic, flint pebbles and stainless steel are used.25 In order to further improve the quality of dispersion and introduce functional groups onto the nanotube surface, selected chemicals can be included in the container during the process. The factors that affect the quality of dispersion include the milling time, rotational speed, size of balls and balls/ nanotube amount ratio. Under certain processing conditions, the particles can be ground to as small as 100nm. This process has been employed to transform carbon nanotubes into smaller nanoparticles, to generate highly curved or closed shell carbon nanostructures from graphite, to enhance the saturation of lithium composition in SWCNTs, to modify the morphologies of cup-stacked carbon nanotubes and to generate different carbon nanoparticles from graphitic carbon for hydrogen storage application.25 Even though ball milling is easy to operate and suitable for powder polymers or monomers, process-induced damage on the nanotubes can occur.

Ball milling is a way to exfoliate graphite using lateral force, as opposed to the Scotch Tape or sonication that mainly use normal force. Ball mills, like the three roll machine, are a common occurrence in industry, for the production of fine particles. During the ball milling process, there are two factors that contribute to the exfoliation. The main factor contributing is the shear force applied by the balls. Using only shear force, one can produce large graphene flakes. The secondary factor is the collisions that occur during milling. Harsh collisions can break these large flakes and can potentially disrupt the crystal structure resulting in a more amorphous mass. So in order to create good-quality, high-area graphene, the collisions have to be minimized.

The ball-milling process is common in grinding machines as well as in reactors where various functional materials can be created by mechanochemical synthesis. A simple milling process reduces both CO2 generation and energy consumption during materials production. Herein a novel mechanochemical approach 1-3) to produce sophisticated carbon nanomaterials is reported. It is demonstrated that unique carbon nanostructures including carbon nanotubes and carbon onions are synthesized by high-speed ball-milling of steel balls. It is considered that the gas-phase reaction takes place around the surface of steel balls under local high temperatures induced by the collision-friction energy in ball-milling process, which results in phase separated unique carbon nanomaterials.

Conventional ball milling is a traditional powder-processing technique, which is mainly used for reducing particle sizes and for the mixing of different materials. The technique is widely used in mineral, pharmaceutical, and ceramic industries, as well as scientific laboratories. The HEBM technique discussed in this chapter is a new technique developed initially for producing new metastable materials, which cannot be produced using thermal equilibrium processes, and thus is very different from conventional ball milling technique. HEBM was first reported by Benjamin [38] in the 1960s. So far, a large range of new materials has been synthesized using HEBM. For example, oxide-dispersion-strengthened alloys are synthesized using a powerful high-energy ball mill (attritor) because conventional ball mills could not provide sufficient grinding energy [38]. Intensive research in the synthesis of new metastable materials by HEBM was stimulated by the pioneering work in the amorphization of the Ni-Nb alloys conducted by Kock et al. in 1983 [39]. Since then, a wide spectrum of metastable materials has been produced, including nanocrystalline [40], nanocomposite [41], nanoporous phases [42], supersaturated solid solutions [43], and amorphous alloys [44]. These new phase transformations induced by HEBM are generally referred as mechanical alloying (MA). At the same time, it was found that at room temperature, HEBM can activate chemical reactions which are normally only possible at high temperatures [45]. This is called reactive milling or mechano-chemistry. Reactive ball milling has produced a large range of nanosized oxides [46], nitrides [47], hydrides [48], and carbide [49] particles.

The major differences between conventional ball milling and the HEBM are listed in the Table 1. The impact energy of HEBM is typically 1000 times higher than the conventional ball milling energy. The dominant events in the conventional ball milling are particle fracturing and size reductions, which correspond to, actually, only the first stage of the HEBM. A longer milling time is therefore generally required for HEBM. In addition to milling energy, the controls of milling atmosphere and temperature are crucial in order to create the desired structural changes or chemical reactions. This table shows that HEBM can cover most work normally performed by conventional ball milling, however, conventional ball milling equipment cannot be used to conduct any HEBM work.

Different types of high-energy ball mills have been developed, including the Spex vibrating mill, planetary ball mill, high-energy rotating mill, and attritors [50]. In the nanotube synthesis, two types of HEBM mills have been used: a vibrating ball mill and a rotating ball mill. The vibrating-frame grinder (Pulverisette O, Fritsch) is shown in Fig. 1a. This mill uses only one large ball (diameter of 50 mm) and the media of the ball and vial can be stainless steel or ceramic tungsten carbide (WC). The milling chamber, as illustrated in Fig. 1b, is sealed with an O-ring so that the atmosphere can be changed via a valve. The pressure is monitored with an attached gauge during milling.

where Mb is the mass of the milling ball, Vmax the maximum velocity of the vial,/the impact frequency, and Mp the mass of powder. The milling intensity is a very important parameter to MA and reactive ball milling. For example, a full amorphization of a crystalline NiZr alloy can only be achieved with a milling intensity above an intensity threshold of 510 ms2 [52]. The amorphization process during ball milling can be seen from the images of transmission electron microscopy (TEM) in Fig. 2a, which were taken from samples milled for different lengths of time. The TEM images show that the size and number of NiZr crystals decrease with increasing milling time, and a full amorphization is achieved after milling for 165 h. The corresponding diffraction patterns in Fig. 2b confirm this gradual amorphization process. However, when milling below the intensity threshold, a mixture of nanocrystalline and amorphous phases is produced. This intensity threshold depends on milling temperature and alloy composition [52].

Figure 2. (a) Dark-field TEM image of Ni10Zr7 alloy milled for 0.5, 23, 73, and 165 h in the vibrating ball mill with a milling intensity of 940 ms2. (b) Corresponding electron diffraction patterns [52].

Fig. 3 shows a rotating steel mill and a schematic representation of milling action inside the milling chamber. The mill has a rotating horizontal cell loaded with several hardened steel balls. As the cell rotates, the balls drop onto the powder that is being ground. An external magnet is placed close to the cell to increase milling energy [53]. Different milling actions and intensities can be realized by adjusting the cell rotation rate and magnet position.

The atmosphere inside the chamber can be controlled, and adequate gas has to be selected for different milling experiments. For example, during the ball milling of pure Zr powder in the atmosphere of ammonia (NH3), a series of chemical reactions occur between Zr and NH3 [54,55]. The X-ray diffraction (XRD) patterns in Fig. 4 show the following reaction sequence as a function of milling time:

The mechanism of a HEBM process is quite complicated. During the HEBM, material particles are repeatedly flattened, fractured, and welded. Every time two steel balls collide or one ball hits the chamber wall, they trap some particles between their surfaces. Such high-energy impacts severely deform the particles and create atomically fresh, new surfaces, as well as a high density of dislocations and other structural defects [44]. A high defect density induced by HEBM can accelerate the diffusion process [56]. Alternatively, the deformation and fracturing of particles causes continuous size reduction and can lead to reduction in diffusion distances. This can at least reduce the reaction temperatures significantly, even if the reactions do not occur at room temperature [57,58]. Since newly created surfaces are most often very reactive and readily oxidize in air, the HEBM has to be conducted in an inert atmosphere. It is now recognized that the HEBM, along with other non-equilibrium techniques such as rapid quenching, irradiation/ion-implantation, plasma processing, and gas deposition, can produce a series of metastable and nanostructured materials, which are usually difficult to prepare using melting or conventional powder metallurgy methods [59,60]. In the next section, detailed structural and morphological changes of graphite during HEBM will be presented.

Ball milling and ultrasonication were used to reduce the particle size and distribution. During ball milling the weight (grams) ratio of balls-to-clay particles was 100:2.5 and the milling operation was run for 24 hours. The effect of different types of balls on particle size reduction and narrowing particle size distribution was studied. The milled particles were dispersed in xylene to disaggregate the clumps. Again, ultrasonication was done on milled samples in xylene. An investigation on the amplitude (80% and 90%), pulsation rate (5 s on and 5 s off, 8 s on and 4 s off) and time (15 min, 1 h and 4 h) of the ultrasonication process was done with respect to particle size distribution and the optimum conditions in our laboratory were determined. A particle size analyzer was used to characterize the nanoparticles based on the principles of laser diffraction and morphological studies.

what's the difference between sag mill and ball mill - jxsc machine

what's the difference between sag mill and ball mill - jxsc machine

A mill is a grinder used to grind and blend solid or hard materials into smaller pieces by means of shear, impact and compression methods. Grinding mill machine is an essential part of many industrial processes, there are mainly five types of mills to cover more than 90% materials size-reduction applications.

Do you the difference between the ball mill, rod mills, SAG mill, tube mill, pebble mill? In the previous article, I made a comparison of ball mill and rod mill. Today, we will learn about the difference between SAG mill vs ball mill.

AG/SAG is short for autogenous mill and semi-autogenous mill, it combines with two functions of crushing and grinding, uses the ground material itself as the grinding media, through the mutual impact and grinding action to gradually reduce the material size. SAG mill is usually used to grind large pieces into small pieces, especially for the pre-processing of grinding circuits, thus also known as primary stage grinding machine. Based on the high throughput and coarse grind, AG mills produce coarse grinds often classify mill discharge with screens and trommel. SAG mills grinding media includes some large and hard rocks, filled rate of 9% 20%. SAG mill grind ores through impact, attrition, abrasion forces. In practice, for a given ore and equal processing conditions, the AG milling has a finer grind than SAG mills.

The working principle of the self-grinding machine is basically the same as the ball mill, the biggest difference is that the sag grinding machine uses the crushed material inside the cylinder as the grinding medium, the material constantly impacts and grinding to gradually pulverize. Sometimes, in order to improve the processing capacity of the mill, a small amount of steel balls be added appropriately, usually occupying 2-3% of the volume of the mill (that is semi-autogenous grinding).

High capacity Ability to grind multiple types of ore in various circuit configurations, reduces the complexity of maintenance and coordination. Compared with the traditional tumbling mill, the autogenous mill reduces the consumption of lining plates and grinding media, thus have a lower operation cost. The self-grinding machine can grind the material to 0.074mm in one time, and its content accounts for 20% ~ 50% of the total amount of the product. Grinding ratio can reach 4000 ~ 5000, more than ten times higher than ball, rod mill.

Ball mills are fine grinders, have horizontal ball mill and vertical ball mill, their cylinders are partially filled with steel balls, manganese balls, or ceramic balls. The material is ground to the required fineness by rotating the cylinder causing friction and impact. The internal machinery of the ball mill grinds the material into powder and continues to rotate if extremely high precision and precision is required.

The ball mill can be applied in the cement production plants, mineral processing plants and where the fine grinding of raw material is required. From the volume, the ball mill divide into industrial ball mill and laboratory use the small ball mill, sample grinding test. In addition, these mills also play an important role in cold welding, alloy production, and thermal power plant power production.

The biggest characteristic of the sag mill is that the crushing ratio is large. The particle size of the materials to be ground is 300 ~ 400mm, sometimes even larger, and the minimum particle size of the materials to be discharged can reach 0.1 mm. The calculation shows that the crushing ratio can reach 3000 ~ 4000, while the ball mills crushing ratio is smaller. The feed size is usually between 20-30mm and the product size is 0-3mm.

Both the autogenous grinding mill and the ball mill feed parts are welded with groove and embedded inner wear-resistant lining plate. As the sag mill does not contain grinding medium, the abrasion and impact on the equipment are relatively small.

The feed of the ball mill contains grinding balls. In order to effectively reduce the direct impact of materials on the ball mill feed bushing and improve the service life of the ball mill feed bushing, the feeding point of the groove in the feeding part of the ball mill must be as close to the side of the mill barrel as possible. And because the ball mill feed grain size is larger, ball mill feeding groove must have a larger slope and height, so that feed smooth.

Since the power of the autogenous tumbling mill is relatively small, it is appropriate to choose dynamic and static pressure bearing. The ball bearing liner is made of lead-based bearing alloy, and the back of the bearing is formed with a waist drum to form a contact centering structure, with the advantages of flexible movement. The bearing housing is lubricated by high pressure during start-up and stop-up, and the oil film is formed by static pressure. The journal is lifted up to prevent dry friction on the sliding surface, and the starting energy moment is reduced. The bearing lining is provided with a snake-shaped cooling water pipe, which can supply cooling water when necessary to reduce the temperature of the bearing bush. The cooling water pipe is made of red copper which has certain corrosion resistance.

Ball mill power is relatively large, the appropriate choice of hydrostatic sliding bearing. The main bearing bush is lined with babbitt alloy bush, each bush has two high-pressure oil chambers, high-pressure oil has been supplied to the oil chamber before and during the operation of the mill, the high-pressure oil enters the oil chamber through the shunting motor, and the static pressure oil film is compensated automatically to ensure the same oil film thickness To provide a continuous static pressure oil film for mill operation, to ensure that the journal and the bearing Bush are completely out of contact, thus greatly reducing the mill start-up load, and can reduce the impact on the mill transmission part, but also can avoid the abrasion of the bearing Bush, the service life of the bearing Bush is prolonged. The pressure indication of the high pressure oil circuit can be used to reflect the load of the mill indirectly. When the mill stops running, the high pressure oil will float the Journal, and the Journal will stop gradually in the bush, so that the Bush will not be abraded. Each main bearing is equipped with two temperature probe, dynamic monitoring of the bearing Bush temperature, when the temperature is greater than the specified temperature value, it can automatically alarm and stop grinding. In order to compensate for the change of the mill length due to temperature, there is a gap between the hollow journal at the feeding end and the bearing Bush width, which allows the journal to move axially on the bearing Bush. The two ends of the main bearing are sealed in an annular way and filled with grease through the lubricating oil pipe to prevent the leakage of the lubricating oil and the entry of dust.

The end cover of the autogenous mill is made of steel plate and welded into one body; the structure is simple, but the rigidity and strength are low; the liner of the autogenous mill is made of high manganese steel.

The end cover and the hollow shaft can be made into an integral or split type according to the actual situation of the project. No matter the integral or split type structure, the end cover and the hollow shaft are all made of Casting After rough machining, the key parts are detected by ultrasonic, and after finishing, the surface is detected by magnetic particle. The surface of the hollow shaft journal is Polished after machining. The end cover and the cylinder body are all connected by high-strength bolts. Strict process measures to control the machining accuracy of the joint surface stop, to ensure reliable connection and the concentricity of the two end journal after final assembly. According to the actual situation of the project, the cylinder can be made as a whole or divided, with a flanged connection and stop positioning. All welds are penetration welds, and all welds are inspected by ultrasonic nondestructive testing After welding, the whole Shell is returned to the furnace for tempering stress relief treatment, and after heat treatment, the shell surface is shot-peened. The lining plate of the ball mill is usually made of alloy material.

The transmission part comprises a gear and a gear, a gear housing, a gear housing and an accessory thereof. The big gear of the transmission part of the self-grinding machine fits on the hollow shaft of the discharge material, which is smaller in size, but the seal of the gear cover is not good, and the ore slurry easily enters the hollow shaft of the discharge material, causing the hollow shaft to wear.

The big gear of the ball mill fits on the mill shell, the size is bigger, the big gear is divided into half structure, the radial and axial run-out of the big gear are controlled within the national standard, the aging treatment is up to the standard, and the stress and deformation after processing are prevented. The big gear seal adopts the radial seal and the reinforced big gear shield. It is welded and manufactured in the workshop. The geometric size is controlled, the deformation is prevented and the sealing effect is ensured. The small gear transmission device adopts the cast iron base, the bearing base and the bearing cap are processed at the same time to reduce the vibration in operation. Large and small gear lubrication: The use of spray lubrication device timing quantitative forced spray lubrication, automatic control, no manual operation. The gear cover is welded by profile steel and high-quality steel plate. In order to enhance the stiffness of the gear cover, the finite element analysis is carried out, and the supporting structure is added in the weak part according to the analysis results.

The self-mill adopts the self-return device to realize the discharge of the mill. The self-returning device is located in the revolving part of the mill, and the material forms a self-circulation in the revolving part of the mill through the self-returning device, discharging the qualified material from the mill, leading the unqualified material back into the revolving part to participate in the grinding operation.

The ball mill adopts a discharge screen similar to the ball mill, and the function of blocking the internal medium of the overflow ball mill is accomplished inside the rotary part of the ball mill. The discharge screen is only responsible for forcing out a small amount of the medium that overflows into the discharge screen through the internal welding reverse spiral, to achieve forced discharge mill.

The slow drive consists of a brake motor, a coupling, a planetary reducer and a claw-type clutch. The device is connected to a pinion shaft and is used for mill maintenance and replacement of liners. In addition, after the mill is shut down for a long time, the slow-speed transmission device before starting the main motor can eliminate the eccentric load of the steel ball, loosen the consolidation of the steel ball and materials, ensure safe start, avoid overloading of the air clutch, and play a protective role. The slow-speed transmission device can realize the point-to-point reverse in the electronic control design. When connecting the main motor drive, the claw-type Clutch automatically disengages, the maintenance personnel should pay attention to the safety.

The slow drive device of the ball mill is provided with a rack and pinion structure, and the operating handle is moved to the side away from the cylinder body The utility model not only reduces the labor intensity but also ensures the safety of the operators.

types of end mills & difference between end mill and drill bit | what is end milling | cnclathing

types of end mills & difference between end mill and drill bit | what is end milling | cnclathing

Highly automated milling is a versatile machining process that is capable of producing components in almost any shape. There are a wide variety of CNC milling operations adopted for different manufacturing purposes. End milling mainly differs from other processes due to the type of tooling it is used for cutting materials. In this article, well outline the types of end mills, what is end milling, and also figure out the difference between end mill and drill bit.

End milling is a type of milling process that can be used to produce slots, shoulders, die cavities, contours, profiles, and other milling parts. End milling uses the end mill which is a cylindrical cutter with multiple cutting edges on both its periphery and its tip, permitting end cutting and peripheral cutting.

The end mill is a type of milling cutter designed to be able to cut axially and applicable in end milling, profile milling, tracer milling, face milling, and plunging. End mills and other cutting tools can be made from a host of materials, such as the carbide inserts (suitable for high production milling), high-speed steel (when a special tool shape needed), ceramics inserts (for high-speed machining with high volume), and diamond inserts (offer tight tolerances). High-speed steel (HSS) and tungsten carbide are two of the most common materials for making the end mill. End mills allow precision cutting to manufacture milled parts for broad applications, including jewelry, sign making, mold making, circuit boards, wood engravings, machine parts, and more. Endmills are available in varying lengths, diameters, flutes, and types.

1. End mills in different shapes Ball nose end mill: with a radius at the bottom which makes for a greater surface finish, produces a rounded pass, ideal for 3D contour work, shallow slotting, pocketing, and contouring applications. V-bits: with small angles and tips, produce a V-shaped pass, used for engraving, narrow cuts, and small, delicate engraving of lettering and lines, particularly for making signs, its also available for exceptionally sharp edges. The v-bit end mill comes in two forms- 60or 90V-bit. Fishtail end mill: with cutting edges on one end, which may be much thinner than the other end, fishtail end mills can plunge directly into your material and produce a flat surface, prevent any splintering or breakout, create clean edges on thin material and make pockets with flat bottoms, suitable for plunge routing and producing precise contours, like signs. With fishtail end mills, you can also have nice square corners at the bottom of any inset section of geometry. Square end mill: also known as flat end mills, are general-purpose mills that generate flat-surfaced cuts with perfect 90 corners in the workpiece, involves milling operations like side milling, face milling, and more. Square endmills can be used in the roughing or finishing stage. Bull-nose end mills: also called corner radius end mills, this type of cutter is a combination of fishtail and ball-nose, also a flat bottom but with rounded corners. Bull-nose end mills are often used to mill molds (plastic injection molds, die cast molds, etc.)

2. End mills in different number of flutesThe spiral-shaped cutting teeth on the end mill are flutes, which offer an empty path for cutting chip removal during the machining process. End mills available in 2, 3, or 4 flutes, 2 and 4 flutes end mill are more common. More flutes create a smoother surface finish, while fewer flutes are best at chip clearing and keep heat from building up. 2 Flute end Mill: suitable to work with wood and aluminum because they produce large chips 4 Flute end Mill: used to machine most other materials, cut harder materials than 2 flutes

3. End mills in different materials High-speed steel (HSS): cheaper than carbide tools but dull faster as well Carbide: is brittle and can shatter, provide better wear resistance and toughness. Carbide end mills are extremely heat-resistant and used for high-speed applications on some of the hardest materials. Solid Carbide end mills: considerably harder, rigid, and more wear-resistant than other types.

1. Rotary end mills cut side to side or in the horizontal direction, lots of mills can cut both axially and laterally, while drill bits that plunged directly into the material only move up and down and cut in vertically.

4. The tip of drill bits is often ground in cone-shape, the exception is diamond drill bits which have a flat end, end mills are available in various shapes and specifications, a regular end mill has a flat tip, and a ball nose end mill with a profile at the cutting end. You can choose a proper end mill according to the materials to be cut and surface finish required.

ball mill: operating principles, components, uses, advantages and

ball mill: operating principles, components, uses, advantages and

A ball mill also known as pebble mill or tumbling mill is a milling machine that consists of a hallow cylinder containing balls; mounted on a metallic frame such that it can be rotated along its longitudinal axis. The balls which could be of different diameter occupy 30 50 % of the mill volume and its size depends on the feed and mill size. The large balls tend to break down the coarse feed materials and the smaller balls help to form fine product by reducing void spaces between the balls. Ball mills grind material by impact and attrition.

Several types of ball mills exist. They differ to an extent in their operating principle. They also differ in their maximum capacity of the milling vessel, ranging from 0.010 liters for planetary ball mills, mixer mills, or vibration ball mills to several 100 liters for horizontal rolling ball mills.

Im grateful for the information about using a ball mill for pharmaceutical products as it produces very fine powder. My friend is working for a pharmaceutical company and this is a good article to share with her. Its good to know that ball mills are suitable for milling toxic materials since they can be used in a completely enclosed for. Thanks for the tips!

basic introduction of various types of milling cutters - mech4study

basic introduction of various types of milling cutters - mech4study

Types of Milling Cutters:1.End mill:It has both side teeth so it can be very successfully used in drilling operation. The word end mill is generally use to refer flat bottom cutters. The basic difference between drill bit and end mill cutter is that the drill bit can cut only in axial direction but this cutter can cut in all directions. This cutter has one or more flutes and mostly used in end milling operation. It is made by High speed steel or harder material. This cutters mainly available in two types. The first one is known as center cutting in which the cutter has cutting edges on both the side and the other one is non center cutting edge in which the cutting edge is only in one side.2.Roughing end mill:Roughing end mills are also knows as rippa cutters. This cutters gives superlative performance in hardest operating condition. As the name implies it is used to remove large amount of material. This kind of cutter utilizes a wavy tooth from. These cutters forms very small chips which results rough surface finish.

1.End mill:It has both side teeth so it can be very successfully used in drilling operation. The word end mill is generally use to refer flat bottom cutters. The basic difference between drill bit and end mill cutter is that the drill bit can cut only in axial direction but this cutter can cut in all directions. This cutter has one or more flutes and mostly used in end milling operation. It is made by High speed steel or harder material. This cutters mainly available in two types. The first one is known as center cutting in which the cutter has cutting edges on both the side and the other one is non center cutting edge in which the cutting edge is only in one side.2.Roughing end mill:Roughing end mills are also knows as rippa cutters. This cutters gives superlative performance in hardest operating condition. As the name implies it is used to remove large amount of material. This kind of cutter utilizes a wavy tooth from. These cutters forms very small chips which results rough surface finish.

2.Roughing end mill:Roughing end mills are also knows as rippa cutters. This cutters gives superlative performance in hardest operating condition. As the name implies it is used to remove large amount of material. This kind of cutter utilizes a wavy tooth from. These cutters forms very small chips which results rough surface finish.

Some features of Rough End Mill Cutter areOptimum performanceSuper QualityAnti-corrosiveHigh straight3.Ball nose cutters:Ball Nose Cutter is manufactured from qualitative carbide rods. As the name implies this cutter has ball like shape at its nose which make it able to cut three dimensional shapes very effectively.The main advantages of ball mill cutters are:Sturdy natureLow maintenanceRust resistanceLonger life serviceEasy to use4.Slab mill:This type of cutter is best in quality and can be bought from market with sharp edges. Moreover to this, these milling cutters are light in weight and can be used safely for longer years. This cutter is used to remove large material from a slab or machining a large surface. It can be used with both horizontal and vertical or universal milling machine.Various features of this cutter are:Available in different sizes.Hassle free installation.Sharp edges.5.Side & face cutter:Side or face cutters are manly used to cut slot. This cutter has teeth both its side and circumference. It is available in varying diameters and widths depend on application.6.Hob cutter:Hob is machine process of gear cutting. A cross section of the cutter tooth will generate the require shape on the work-piece. Hob cutter is specialist milling machine which is widely use in automobile industry. It is manufactured from prime grade material which insure high durability and functionality. These are manufactured with quality control process.7.Face mill:As the name implies, this tool is used to perform facing operation on any work piece. Facing is an operation in which large surface area machined to create large flat area. This tool has large diameter which is used to perform a facing operation. This device is manufactured by top quality component which ensure its high tensile strength robustness and maximum durability. Mostly 45 degree lead angle cutters are used for this purpose.There are some feature of this cutter:Dimensional accuracyCorrosion ResistantHigh strengthRobust ConstructionAbrasion Resistant8.Fly cutter:It is a cutting tool set transversely and revolving with the arbor of a lathe and acting upon work fed into its circular path.A fly cutter is composed of a body into which one or two tool bits are inserted. As the entire unit rotates, the tool bits take broad, shallow facing cuts. Face mills are more ideal in various respects , but tend to be expensive, whereas fly cutters are very inexpensive.9. Woodruff cutter:Woodruff cutters are used to make the seat. It is slightly hollow ground on the sides for relief and the teeth are not side cutting. The teeth come in both straight and staggered varieties. These qualitative cutters are widely use in order to make key seats in shaft of various shapes and sizes.Here are some feature about Woodruff Cutter:High performanceLong service lifeEase of use10. Hollow mill:Hollow milling cutters, more often called simply hollow mills, are essentially inside-out end mills. They are shaped like a piece of pipe, with their cutting edges on the inside surface. They are used on turret lathes and screw machines as an alternative to turning with a box tool, or on milling machines or drill presses to finish a cylindrical boss.This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

3.Ball nose cutters:Ball Nose Cutter is manufactured from qualitative carbide rods. As the name implies this cutter has ball like shape at its nose which make it able to cut three dimensional shapes very effectively.

The main advantages of ball mill cutters are:Sturdy natureLow maintenanceRust resistanceLonger life serviceEasy to use4.Slab mill:This type of cutter is best in quality and can be bought from market with sharp edges. Moreover to this, these milling cutters are light in weight and can be used safely for longer years. This cutter is used to remove large material from a slab or machining a large surface. It can be used with both horizontal and vertical or universal milling machine.Various features of this cutter are:Available in different sizes.Hassle free installation.Sharp edges.5.Side & face cutter:Side or face cutters are manly used to cut slot. This cutter has teeth both its side and circumference. It is available in varying diameters and widths depend on application.6.Hob cutter:Hob is machine process of gear cutting. A cross section of the cutter tooth will generate the require shape on the work-piece. Hob cutter is specialist milling machine which is widely use in automobile industry. It is manufactured from prime grade material which insure high durability and functionality. These are manufactured with quality control process.7.Face mill:As the name implies, this tool is used to perform facing operation on any work piece. Facing is an operation in which large surface area machined to create large flat area. This tool has large diameter which is used to perform a facing operation. This device is manufactured by top quality component which ensure its high tensile strength robustness and maximum durability. Mostly 45 degree lead angle cutters are used for this purpose.There are some feature of this cutter:Dimensional accuracyCorrosion ResistantHigh strengthRobust ConstructionAbrasion Resistant8.Fly cutter:It is a cutting tool set transversely and revolving with the arbor of a lathe and acting upon work fed into its circular path.A fly cutter is composed of a body into which one or two tool bits are inserted. As the entire unit rotates, the tool bits take broad, shallow facing cuts. Face mills are more ideal in various respects , but tend to be expensive, whereas fly cutters are very inexpensive.9. Woodruff cutter:Woodruff cutters are used to make the seat. It is slightly hollow ground on the sides for relief and the teeth are not side cutting. The teeth come in both straight and staggered varieties. These qualitative cutters are widely use in order to make key seats in shaft of various shapes and sizes.Here are some feature about Woodruff Cutter:High performanceLong service lifeEase of use10. Hollow mill:Hollow milling cutters, more often called simply hollow mills, are essentially inside-out end mills. They are shaped like a piece of pipe, with their cutting edges on the inside surface. They are used on turret lathes and screw machines as an alternative to turning with a box tool, or on milling machines or drill presses to finish a cylindrical boss.This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

4.Slab mill:This type of cutter is best in quality and can be bought from market with sharp edges. Moreover to this, these milling cutters are light in weight and can be used safely for longer years. This cutter is used to remove large material from a slab or machining a large surface. It can be used with both horizontal and vertical or universal milling machine.

Various features of this cutter are:Available in different sizes.Hassle free installation.Sharp edges.5.Side & face cutter:Side or face cutters are manly used to cut slot. This cutter has teeth both its side and circumference. It is available in varying diameters and widths depend on application.6.Hob cutter:Hob is machine process of gear cutting. A cross section of the cutter tooth will generate the require shape on the work-piece. Hob cutter is specialist milling machine which is widely use in automobile industry. It is manufactured from prime grade material which insure high durability and functionality. These are manufactured with quality control process.7.Face mill:As the name implies, this tool is used to perform facing operation on any work piece. Facing is an operation in which large surface area machined to create large flat area. This tool has large diameter which is used to perform a facing operation. This device is manufactured by top quality component which ensure its high tensile strength robustness and maximum durability. Mostly 45 degree lead angle cutters are used for this purpose.There are some feature of this cutter:Dimensional accuracyCorrosion ResistantHigh strengthRobust ConstructionAbrasion Resistant8.Fly cutter:It is a cutting tool set transversely and revolving with the arbor of a lathe and acting upon work fed into its circular path.A fly cutter is composed of a body into which one or two tool bits are inserted. As the entire unit rotates, the tool bits take broad, shallow facing cuts. Face mills are more ideal in various respects , but tend to be expensive, whereas fly cutters are very inexpensive.9. Woodruff cutter:Woodruff cutters are used to make the seat. It is slightly hollow ground on the sides for relief and the teeth are not side cutting. The teeth come in both straight and staggered varieties. These qualitative cutters are widely use in order to make key seats in shaft of various shapes and sizes.Here are some feature about Woodruff Cutter:High performanceLong service lifeEase of use10. Hollow mill:Hollow milling cutters, more often called simply hollow mills, are essentially inside-out end mills. They are shaped like a piece of pipe, with their cutting edges on the inside surface. They are used on turret lathes and screw machines as an alternative to turning with a box tool, or on milling machines or drill presses to finish a cylindrical boss.This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

6.Hob cutter:Hob is machine process of gear cutting. A cross section of the cutter tooth will generate the require shape on the work-piece. Hob cutter is specialist milling machine which is widely use in automobile industry. It is manufactured from prime grade material which insure high durability and functionality. These are manufactured with quality control process.7.Face mill:As the name implies, this tool is used to perform facing operation on any work piece. Facing is an operation in which large surface area machined to create large flat area. This tool has large diameter which is used to perform a facing operation. This device is manufactured by top quality component which ensure its high tensile strength robustness and maximum durability. Mostly 45 degree lead angle cutters are used for this purpose.

6.Hob cutter:Hob is machine process of gear cutting. A cross section of the cutter tooth will generate the require shape on the work-piece. Hob cutter is specialist milling machine which is widely use in automobile industry. It is manufactured from prime grade material which insure high durability and functionality. These are manufactured with quality control process.7.Face mill:As the name implies, this tool is used to perform facing operation on any work piece. Facing is an operation in which large surface area machined to create large flat area. This tool has large diameter which is used to perform a facing operation. This device is manufactured by top quality component which ensure its high tensile strength robustness and maximum durability. Mostly 45 degree lead angle cutters are used for this purpose.

7.Face mill:As the name implies, this tool is used to perform facing operation on any work piece. Facing is an operation in which large surface area machined to create large flat area. This tool has large diameter which is used to perform a facing operation. This device is manufactured by top quality component which ensure its high tensile strength robustness and maximum durability. Mostly 45 degree lead angle cutters are used for this purpose.

As the name implies, this tool is used to perform facing operation on any work piece. Facing is an operation in which large surface area machined to create large flat area. This tool has large diameter which is used to perform a facing operation. This device is manufactured by top quality component which ensure its high tensile strength robustness and maximum durability. Mostly 45 degree lead angle cutters are used for this purpose.

There are some feature of this cutter:Dimensional accuracyCorrosion ResistantHigh strengthRobust ConstructionAbrasion Resistant8.Fly cutter:It is a cutting tool set transversely and revolving with the arbor of a lathe and acting upon work fed into its circular path.A fly cutter is composed of a body into which one or two tool bits are inserted. As the entire unit rotates, the tool bits take broad, shallow facing cuts. Face mills are more ideal in various respects , but tend to be expensive, whereas fly cutters are very inexpensive.9. Woodruff cutter:Woodruff cutters are used to make the seat. It is slightly hollow ground on the sides for relief and the teeth are not side cutting. The teeth come in both straight and staggered varieties. These qualitative cutters are widely use in order to make key seats in shaft of various shapes and sizes.Here are some feature about Woodruff Cutter:High performanceLong service lifeEase of use10. Hollow mill:Hollow milling cutters, more often called simply hollow mills, are essentially inside-out end mills. They are shaped like a piece of pipe, with their cutting edges on the inside surface. They are used on turret lathes and screw machines as an alternative to turning with a box tool, or on milling machines or drill presses to finish a cylindrical boss.This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

There are some feature of this cutter:Dimensional accuracyCorrosion ResistantHigh strengthRobust ConstructionAbrasion Resistant8.Fly cutter:It is a cutting tool set transversely and revolving with the arbor of a lathe and acting upon work fed into its circular path.A fly cutter is composed of a body into which one or two tool bits are inserted. As the entire unit rotates, the tool bits take broad, shallow facing cuts. Face mills are more ideal in various respects , but tend to be expensive, whereas fly cutters are very inexpensive.9. Woodruff cutter:Woodruff cutters are used to make the seat. It is slightly hollow ground on the sides for relief and the teeth are not side cutting. The teeth come in both straight and staggered varieties. These qualitative cutters are widely use in order to make key seats in shaft of various shapes and sizes.Here are some feature about Woodruff Cutter:High performanceLong service lifeEase of use10. Hollow mill:Hollow milling cutters, more often called simply hollow mills, are essentially inside-out end mills. They are shaped like a piece of pipe, with their cutting edges on the inside surface. They are used on turret lathes and screw machines as an alternative to turning with a box tool, or on milling machines or drill presses to finish a cylindrical boss.This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

There are some feature of this cutter:Dimensional accuracyCorrosion ResistantHigh strengthRobust ConstructionAbrasion Resistant8.Fly cutter:It is a cutting tool set transversely and revolving with the arbor of a lathe and acting upon work fed into its circular path.A fly cutter is composed of a body into which one or two tool bits are inserted. As the entire unit rotates, the tool bits take broad, shallow facing cuts. Face mills are more ideal in various respects , but tend to be expensive, whereas fly cutters are very inexpensive.9. Woodruff cutter:Woodruff cutters are used to make the seat. It is slightly hollow ground on the sides for relief and the teeth are not side cutting. The teeth come in both straight and staggered varieties. These qualitative cutters are widely use in order to make key seats in shaft of various shapes and sizes.Here are some feature about Woodruff Cutter:High performanceLong service lifeEase of use10. Hollow mill:Hollow milling cutters, more often called simply hollow mills, are essentially inside-out end mills. They are shaped like a piece of pipe, with their cutting edges on the inside surface. They are used on turret lathes and screw machines as an alternative to turning with a box tool, or on milling machines or drill presses to finish a cylindrical boss.This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

8.Fly cutter:It is a cutting tool set transversely and revolving with the arbor of a lathe and acting upon work fed into its circular path.A fly cutter is composed of a body into which one or two tool bits are inserted. As the entire unit rotates, the tool bits take broad, shallow facing cuts. Face mills are more ideal in various respects , but tend to be expensive, whereas fly cutters are very inexpensive.9. Woodruff cutter:Woodruff cutters are used to make the seat. It is slightly hollow ground on the sides for relief and the teeth are not side cutting. The teeth come in both straight and staggered varieties. These qualitative cutters are widely use in order to make key seats in shaft of various shapes and sizes.

It is a cutting tool set transversely and revolving with the arbor of a lathe and acting upon work fed into its circular path.A fly cutter is composed of a body into which one or two tool bits are inserted. As the entire unit rotates, the tool bits take broad, shallow facing cuts. Face mills are more ideal in various respects , but tend to be expensive, whereas fly cutters are very inexpensive.

9. Woodruff cutter:Woodruff cutters are used to make the seat. It is slightly hollow ground on the sides for relief and the teeth are not side cutting. The teeth come in both straight and staggered varieties. These qualitative cutters are widely use in order to make key seats in shaft of various shapes and sizes.

Here are some feature about Woodruff Cutter:High performanceLong service lifeEase of use10. Hollow mill:Hollow milling cutters, more often called simply hollow mills, are essentially inside-out end mills. They are shaped like a piece of pipe, with their cutting edges on the inside surface. They are used on turret lathes and screw machines as an alternative to turning with a box tool, or on milling machines or drill presses to finish a cylindrical boss.This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

Here are some feature about Woodruff Cutter:High performanceLong service lifeEase of use10. Hollow mill:Hollow milling cutters, more often called simply hollow mills, are essentially inside-out end mills. They are shaped like a piece of pipe, with their cutting edges on the inside surface. They are used on turret lathes and screw machines as an alternative to turning with a box tool, or on milling machines or drill presses to finish a cylindrical boss.This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

Here are some feature about Woodruff Cutter:High performanceLong service lifeEase of use10. Hollow mill:Hollow milling cutters, more often called simply hollow mills, are essentially inside-out end mills. They are shaped like a piece of pipe, with their cutting edges on the inside surface. They are used on turret lathes and screw machines as an alternative to turning with a box tool, or on milling machines or drill presses to finish a cylindrical boss.This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

10. Hollow mill:Hollow milling cutters, more often called simply hollow mills, are essentially inside-out end mills. They are shaped like a piece of pipe, with their cutting edges on the inside surface. They are used on turret lathes and screw machines as an alternative to turning with a box tool, or on milling machines or drill presses to finish a cylindrical boss.

This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

This is all about types of milling cutters. If you have any query regarding this article ask by commenting. If you like this article, dont forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.Sharing is Caring :)-Related Posts:General Introduction of Heat TransferBasic Parts of Engine and its TerminologyDifferent Types of Air CompressorWhat is Servomotor and its Types?Types of cams and followersTypes of Control ValvesDifferent Types of Shaper MachineTypes of Grinding Machine

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