milling cutter - 3d cad models & 2d drawings

milling cutter - 3d cad models & 2d drawings

Milling cutters are cutting tools typically used in milling machines or machining centres to perform milling operations (and occasionally in other machine tools). They remove material by their movement within the machine (e.g., a ball nose mill) or directly from the cutter's shape (e.g., a form tool such as a hobbing cutter).

End mills (middle row in image) are those tools which have cutting teeth at one end, as well as on the sides. The words end mill are generally used to refer to flat bottomed cutters, but also include rounded cutters (referred to as ball nosed) and radiused cutters (referred to as bull nose, or torus). They are usually made from high speed steel or cemented carbide, and have one or more flutes. They are the most common tool used in a vertical mill.

Roughing end mills quickly remove large amounts of material. This kind of end mill utilizes a wavy tooth form cut on the periphery. These wavy teeth form many successive cutting edges producing many small chips, resulting in a relatively rough surface finish, but the swarf takes the form of short thin sections and is more manageable than a thicker more riboon-like section. During cutting, multiple teeth are in simultaneous contact with the workpiece reducing chatter and vibration. Rapid stock removal with heavy milling cuts is sometimes called hogging. Roughing end mills are also sometimes known as "rippa" or "ripper" cutters.

Ball nose cutters or ball end mills (lower row in image) are similar to slot drills, but the end of the cutters are hemispherical. They are ideal for machining 3-dimensional contoured shapes in machining centres, for example in moulds and dies. They are sometimes called ball mills in shop-floor slang, despite the fact that that term also has another meaning. They are also used to add a radius between perpendicular faces to reduce stress concentrations.

There is also a term bull nose cutter, which refers to a cutter having a corner radius that is fairly large, although less than the spherical radius (half the cutter diameter) of a ball mill; for example, a 20-mm diameter cutter with a 2-mm radius corner. This usage is analogous to the term bull nose center referring to lathe centers with truncated cones; in both cases, the silhouette is essentially a rectangle with its corners truncated (by either a chamfer or radius Don).

Slab mills are used either by themselves or in gang milling operations on manual horizontal or universal milling machines to machine large broad surfaces quickly. They have been superseded by the use of cemented carbide-tipped face mills which are then used in vertical mills or machining centres.

The side-and-face cutter is designed with cutting teeth on its side as well as its circumference. They are made in varying diameters and widths depending on the application. The teeth on the side allow the cutter to make unbalanced cuts (cutting on one side only) without deflecting the cutter as would happen with a slitting saw or slot cutter (no side teeth).

Cutters of this form factor were the earliest milling cutters developed. From the 1810s to at least the 1880s they were the most common form of milling cutter, whereas today that distinction probably goes to end mills.

These cutters are a type of form tool and are used in hobbing machines to generate gears. A cross section of the cutter's tooth will generate the required shape on the workpiece, once set to the appropriate conditions (blank size). A hobbing machine is a specialised milling machine.

Whereas a hob engages the work much as a mating gear would (and cuts the blank progressively until it reaches final shape), a thread milling cutter operates much like an endmill, traveling around the work in a helical interpolation.

A face mill is a cutter designed for facing as opposed to e.g., creating a pocket (end mills). The cutting edges of face mills are always located along its sides. As such it must always cut in a horizontal direction at a given depth coming from outside the stock. Multiple teeth distribute the chip load, and since the teeth are normally disposable carbide inserts, this combination allows for very large and efficient face milling.

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. Fly cutters are analogous to face mills in that their purpose is face milling and their individual cutters are replaceable. Face mills are more ideal in various respects (e.g., rigidity, indexability of inserts without disturbing effective cutter diameter or tool length offset, depth-of-cut capability), but tend to be expensive, whereas fly cutters are very inexpensive.

Most fly cutters simply have a cylindrical center body that holds one tool bit. It is usually a standard left-hand turning tool that is held at an angle of 30 to 60 degrees. Fly cutters with two tool bits have no "official" name but are often called double fly cutters, double-end fly cutters, or fly bars. The latter name reflects that they often take the form of a bar of steel with a tool bit fastened on each end. Often these bits will be mounted at right angles to the bar's main axis, and the cutting geometry is supplied by using a standard right-hand turning tool.

Regular fly cutters (one tool bit, swept diameter usually less than 100mm) are widely sold in machinists' tooling catalogs. Fly bars are rarely sold commercially; they are usually made by the user. Fly bars are perhaps a bit more dangerous to use than endmills and regular fly cutters because of their larger swing. As one machinist put it, running a fly bar is like "running a lawn mower without the deck",[2] that is, the exposed swinging cutter is a rather large opportunity to take in nearby hand tools, rags, fingers, and so on. However, given that a machinist can never be careless with impunity around rotating cutters or workpieces, this just means using the same care as always except with slightly higher stakes. Well-made fly bars in conscientious hands give years of trouble-free, cost-effective service for the facing off of large polygonal workpieces such as die/mold blocks.

Hollow milling cutters, more often called simply hollow mills, are essentially "inside-out endmills". They are shaped like a piece of pipe (but with thicker walls), 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 (such as a trunnion).

A shell mill is any of various milling cutters (typically a face mill or endmill) whose construction takes a modular form, with the shank (arbor) made separately from the body of the cutter, which is called a "shell" and attaches to the shank/arbor via any of several standardized joining methods.

This modular style of construction is appropriate for large milling cutters for about the same reason that large diesel engines use separate pieces for each cylinder and head whereas a smaller engine would use one integrated casting. Two reasons are that (1) for the maker it is more practical (and thus less expensive) to make the individual pieces as separate endeavors than to machine all their features in relation to each other while the whole unit is integrated (which would require a larger machine tool work envelope); and (2) the user can change some pieces while keeping other pieces the same (rather than changing the whole unit). One arbor (at a hypothetical price of USD100) can serve for various shells at different times. Thus 5 different milling cutters may require only USD100 worth of arbor cost, rather than USD500, as long as the workflow of the shop does not require them all to be set up simultaneously. It is also possible that a crashed tool scraps only the shell rather than both the shell and arbor. This would be like crashing a "regular" endmill and being able to reuse the shank rather than losing it along with the flutes.

The most common type of joint between shell and arbor involves a fairly large cylindrical feature at center (to locate the shell concentric to the arbor) and two driving lugs or tangs that drive the shell with a positive engagement (like a dog clutch). Within the central cylindrical area, one or several socket head cap screws fasten the shell to the arbor.

Another type of shell fastening is simply a large-diameter fine thread. The shell then screws onto the arbor just as old-style lathe chuck backplates screw onto the lathe's spindle nose. This method is commonly used on the 2" or 3" boring heads used on knee mills. As with the threaded-spindle-nose lathe chucks, this style of mounting requires that the cutter only take cuts in one rotary direction. Usually (i.e., with right-hand helix orientation) this means only M03, never M04, or in pre-CNC terminology, "only forward, never reverse". One could use a left-hand thread if one needed a mode of use involving the opposite directions (i.e., only M04, never M03).

Although there are many different types of milling cutter, understanding chip formation is fundamental to the use of any of them. As the milling cutter rotates, the material to be cut is fed into it, and each tooth of the cutter cuts away a small chip of material. Achieving the correct size of chip is of critical importance. The size of this chip depends on several variables.

The machinist needs three values: S, F and Depth when deciding how to cut a new material with a new tool. However, he will probably be given values of Vc and Fz from the tool manufacturer. S and F can be calculated from them:

Cutter location is the topic of where to locate the cutter in order to achieve the desired contour (geometry) of the workpiece, given that the cutter's size is non-zero. The most common example is cutter radius compensation (CRC) for endmills, where the centerline of the tool will be offset from the target position by a vector whose distance is equal to the cutter's radius and whose direction is governed by the left/right, climb/conventional, up/down distinction. In most implementations of G-code, it is G40 through G42 that control CRC (G40 cancel, G41 left/climb, G42 right/conventional). The radius values for each tool are entered into the offset register(s) by the CNC operator or machinist, who then tweaks them during production in order to keep the finished sizes within tolerance. Cutter location for 3D contouring in 3-, 4-, or 5-axis milling with a ball-endmill is handled readily by CAM software rather than manual programming. Typically the CAM vector output is postprocessed into G-code by a postprocessor program that is tailored to the particular CNC control model. Some late-model CNC controls accept the vector output directly, and do the translation to servo inputs themselves, internally.

Another important quality of the milling cutter to consider is its ability to deal with the swarf generated by the cutting process. If the swarf is not removed as fast as it is produced, the flutes will clog and prevent the tool cutting efficiently, causing vibration, tool wear and overheating. Several factors affect swarf removal, including the depth and angle of the flutes, the size and shape of the chips, the flow of coolant, and the surrounding material. It may be difficult to predict, but a good machinist will watch out for swarf build up, and adjust the milling conditions if it is observed.

Selecting a milling cutter is not a simple task. There are many variables, opinions and lore to consider, but essentially the machinist is trying to choose a tool which will cut the material to the required specification for the least cost. The cost of the job is a combination of the price of the tool, the time taken by the milling machine, and the time taken by the machinist. Often, for jobs of a large number of parts, and days of machining time, the cost of the tool is lowest of the three costs.

The history of milling cutters is intimately bound up with that of milling machines. Milling evolved from rotary filing, so there is a continuum of development between the earliest milling cutters known, such as that of Jacques de Vaucanson from about the 1760s or 1770s,[3][4] through the cutters of the milling pioneers of the 1810s through 1850s (Whitney, North, Johnson, Nasmyth, and others),[5] to the cutters developed by Joseph R. Brown of Brown & Sharpe in the 1860s, which were regarded as a break from the past[6][7] for their large step forward in tooth coarseness and for the geometry that could take successive sharpenings without losing the clearance (rake, side rake, and so on). De Vries (1910)[7] reported, "This revolution in the science of milling cutters took place in the States about the year 1870, and became generally known in Europe during the Exhibition in Vienna in 1873. However strange it may seem now that this type of cutter has been universally adopted and its undeniable superiority to the old European type is no longer doubted, it was regarded very distrustfully and European experts were very reserved in expressing their judgment. Even we ourselves can remember that after the coarse pitched cutter had been introduced, certain very clever and otherwise shrewd experts and engineers regarded the new cutting tool with many a shake of the head. When[,] however, the Worlds Exhibition at Philadelphia in 1876, exhibited to European experts a universal and many-sided application of the coarse pitched milling cutter which exceeded even the most sanguine expectations, the most far-seeing engineers were then convinced of the immense advantages which the application of the new type opened up for the metalworking industry, and from that time onwards the American type advanced, slowly at first, but later on with rapid strides".[8]

Woodbury provides citations[9] of patents for various advances in milling cutter design, including irregular spacing of teeth (1867), forms of inserted teeth (1872), spiral groove for breaking up the cut (1881), and others. He also provides a citation on how the introduction of vertical mills brought about wider use of the endmill and fly cutter types.[10]

Scientific study by Holz and De Leeuw of the Cincinnati Milling Machine Company[11] made the teeth even coarser and did for milling cutters what F.W. Taylor had done for single-point cutters with his famous scientific cutting studies.

This article uses material from the Wikipedia article "Milling cutter", which is released under the Creative Commons Attribution-Share-Alike License 3.0. There is a list of all authors in Wikipedia

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AutoCAD, SolidWorks, Autodesk Inventor, FreeCAD, Catia, Siemens NX, PTC Creo, Siemens Solid Edge, Microstation, TurboCAD, Draftsight, IronCAD, Spaceclaim, VariCAD, OnShape, IntelliCAD,T-FLEX, VariCAD, TenadoCAD, ProgeCAD, Cadra, ME10, Medusa, Designspark, KeyCreator, Caddy, GstarCAD, Varimetrix, ASCON Kompas-3D, Free Download, Autocad, 2D Library, DXF, DWG, 2D drawing, 3D digital library, STEP, IGES, 3D CAD Models, 3D files, CAD library, 3D CAD files, BeckerCAD, MegaCAD, Topsolid Missler, Vero VisiCAD, Acis SAT, Cimatron, Cadceus, Solidthinking, Unigraphics, Cadkey, ZWCAD, Alibre, Cocreate, MasterCAM, QCAD.org, QCAD, NanoCAD

diy ball mill plans - homemade rod mill drawing

diy ball mill plans - homemade rod mill drawing

By this drawing, it is suggested that a typical homemade laboratory rod mill or ball mill might be fabricated from 20 cm (8 inches) diameter schedule-40 type 316 stainless steel pipe and would be about 38 cm (15 inches) long.

The plans show stainless steel grinding rods for this size of mill may be a graduated charge from 25 to 10 mm diameter (1 inch to 1/2 inch) but variations in size are not essential. Some mineral processing laboratories use a 30 cm diameter x 61 cm long (12-inch x 24 inch) rod mill with 30 and 45 mm rods (1 1/4 inch and 1 3/4 inch). A similar but smaller 30 cm x 30 cm (12-inch x 12 inch) laboratory ball mill with 40, 30, 25, and 20 mm balls (1 1/2, 1 1/4, 1 and 3/4 inch) is used for their ball mill work index calculations. Stainless steel is suggested because the abrasion and corrosion will be negligible, it is easy to clean out and there will be no rust to influence the subsequent metallurgical results. However, mild steel or carbon steel test mills and rods or balls may be desirable for certain ores to duplicate plant flotation or leaching practice when soluble iron has a bearing on the metallurgy or the solution used might react with the commercial mill or media.

Other sizes of rod mills or ball mills can be used but it is suggested that, regardless of the choice, the same mill should be used on all ores and for all tests. This will permit continuous comparisons with past research and with known ores.

The 20 x 38 cm laboratory mill mentioned above is suitable for testing 2000 gram lots of most normal specific gravity ores. If the same quantity of sample and pulp density are used for all tests in the same mill, the results obtained when changing the grinding time will be analysed readily since the length of time required to grind the sample is proportional to the work input.

It is impractical or at least extremely difficult to measure the grinding power consumed by laboratory mills directly because of the high proportion of the power which is consumed in drive inefficiencies and fixed load characteristics. Without very sophisticated instruments, it is difficult to tell the difference between a lab mill whichis loaded with steel and pulp or one with steel alone. Fortunately, it is not necessary to measure this power because alternate means to determine the work index are available.

Where there are no previous records of grinding mill power calculations, it may be necessary to consult with a commercial or an associates laboratory personnel to have the initial work index determinations done on your ore in their laboratories and compared with reference ores. A second method is available when an operating grinding mill is processing an ore which can be tested in the laboratory. By producing the same product screen analysis in the laboratory, a direct comparison between the products in the plant and the laboratory permits calculations of relative work performed. Alternately, when your own research staff have established work indices during previous projects, they will have historical data upon which to base their present project. The research team will find that the straight lines shown on log-log plots of the results from the various ores tested will be useful for comparisons.

The amount of grinding required for any project is established by the efficiency or adequacy of the initial and subsequent separating stages. Hence, once the correlation between grind and recovery has been established, the economic power requirements can be estimated. The most suitable method of grinding which might be with steel or autogenously can then be determined.

Rod mills may have been termed fine crushing machines but two directly opposing statements about their operating costs have been made in the earlier days of this century, one frequently heard that it is cheaper to crush than to grind but today, with the tremendous increase in grinding mill sizes and power utilization, it is doubtful that the statement is still true. Since a rod mill will accept a coarser feed than a ball mill, it fits in naturally as the intermediate comminution step. However, rod mills, like crushers, must be operated under controlled conditions to obtain maximum efficiency and are more difficult to operate than ball mills. Thus, the ultimate choice between a rod mill or ball mill for the primary grind may depend on the operators or designers experience as much as the metallurgists research.

grinding mills - common types

grinding mills - common types

In many industries the final product, or the raw material at somestage of the manufacturing process, is in powdered form and in consequence the rapid and cheap preparation of powdered materials is a matter of considerable economic importance.

In some cases the powdered material may be prepared directly; for example by precipitation from solution, a process which is used in the preparation of certain types of pigments and drugs, or by the vacuum drying of a fine spray of the material, a process which is widely adopted for the preparation of milk powder, soluble coffee extracts and similar products. Such processes are, however, of limited applicability and in by far the greatest number of industrial applications the powdered materials are prepared by the reduction, in some form of mill, of the grain size of the material having an initial size larger than that required in the final product. These processes for the reduction of the particle size of a granular material are known as milling or grinding and it appears that these names are used interchangeably, there being no accepted technical differentiation between the two.

Examples of the first two classes occur in mineral dressing, in which size reduction is used to liberate the desired ore from the gangue and also to reduce the ore to a form in which it presents a large surface to the leaching reagents.

Under the third heading may be classed many medicinal and pharmaceutical products, foodstuffs, fertilizers, insecticides, etc., and under the fourth heading falls the size reduction of mineral ores, etc.; these materials often being reduced to particles of moderate size for ease in handling, storing and loading into trucks and into the holds of ships.

The quantity of powder to be subjected to such processes of size reduction varies widely according to the industries involved, for example in the pharmaceutical industries the quantities involved per annum, can be measured in terms of a few tons, or in the case of certain drugs, possibly a few pounds; whereas in the cement industry the quantities involved run into tens of millions of tons; the British cement industry alone having produced, in round figures, 12 million tons of Portland Cement.

For the preparation of small quantities of powder many types of mill are available but, even so, the ball mill is frequently used. For the grinding of the largest quantities of material however, the ball, tube or rod mill is used almost exclusively, since these are the only types of mill which possess throughput capacity of the required magnitude.

The great range of sizes covered by industrial ball mills is well exemplified by Fig. 1.1 and Fig. 1.2. In the first illustration is shown a laboratory batch mill of about 1-litre capacity, whilst in Fig. 1.2 is shown a tube mill used in the cement industry the tube having a diameter of about 8 ft and length of about 45 ft.

In Fig. 1.3 is shown a large ball mill, designed for the dry grinding of limestone, dolomite, quartz, refractory and similar materials; this type of mill being made in a series of sizes having diameters ranging from about 26 in. to 108 in., with the corresponding lengths of drum ranging from about 15 in. to 55 in.

At this point it is perhaps of value to study the nomenclature used in connection with the mills under consideration, but it must be emphasized that the lines of demarcation between the types to which the names are applied are not very definite.

The term ball mill is usually applied to a mill in which the grinding media are bodies of spherical form (balls) and in which the length of the mill is of the same order as the diameter of the mill body; in rough figures the length is, say, one to three times the diameter of the mill.

The tube mill is a mill in which the grinding bodies are spherical but in which the length of the mill body is greater in proportion to the diameter than is the case of the ball mill; in fact the length to diameter ratio is often of the order of ten to one.

The rod mill is a mill in which the grinding bodies are circular rods instead of balls, and, in order to avoid tangling of the rods, the length to diameter ratio of such mills is usually within the range of about 15 to 1 and 5 to 1.

It will be noticed that the differentiation between ball mill and the tube mill arises only from the different length to diameter ratios involved, and not from any difference in fundamental principles. The rod mill, however, differs in principle in that the grinding bodies are rods instead of spheres whilst a pebble mill is a ball mill in which the grinding bodies are of natural stone or of ceramic material.

As the name implies, in the batch mills, Fig. 1.4a, the charge of powder to be ground is loaded into the mill in a batch and, after the grinding process is completed, is removed in a batch. Clearly such a mode of operation can only be applied to mills of small or moderate sizes; say to mills of up to about 7 ft diameter by about 7 ft long.

In the grate discharge mill, Fig. 1.4b, a diaphragm in the form of a grating confines the ball charge to one end of the mill and the space between the diaphragm and the other end of the mill houses a scoop for the removal of the ground material. The raw material is fed in through a hollow trunnion at the entrance end of the mill and during grinding traverses the ball charge; after which it passes through the grating and is picked up and removed by the discharge scoop or is discharged through peripheral ports. In this connection, it is relevant to mention that scoops are sometimes referred to as lifters in the literature. In the present work, the use of the term lifter will be confined to the description of a certain form of mill liner construction, fitted with lifter bars in order to promote the tumbling of the charge, which will be described in a later section.

In the trunnion overflow mill, Fig. 1.4c the raw material is fed in through a hollow trunnion at one end of the milland the ground product overflows at the other end. In this case, therefore, the grating and discharge scoop are eliminated.

A variant of the grate discharge mill is shown in Fig. 1.4d, in which the discharge scoop is eliminated by the provision of peripheral discharge ports, with a suitable dust hood, at the exit end of the mill.

Within the classes of mills enumerated above there are a number of variations; for example there occur in practice mills in which the shell is divided into a number of chambers by means of perforated diaphragms and it is arranged that the mean diameter of the balls in the various chambers shall decrease towards the discharge end of the mill; such an arrangement being shown in Fig. 1.6. The reason for this distribution of ball size is that, for optimum grinding conditions, the ratio of ball diameter to particle diameter should be approximately constant. In consequence smaller balls should be used for the later stages of the grinding process, where the powder is finer, and by the adoption of a number of chambers in each of which the mean ball diameter is suitably chosen an approximation is made towards the desired constancy in the ratio of the ball size to the particle size.

The problem of the optimum distribution of ball size within a mill will be dealt with more fully in a later chapter, but at this point it is relevant to mention a mill in which the segregation of the balls is brought about by an ingenious method; especially as the mill carries a distinctive name, even though no principles which place it outside the classification given previously are involved.

The Hardinge mill, Fig. 1.7, uses spheres as a grinding agent but the body is of cylindro-conical form and usually has a length to diameter ratio intermediate between those associated with the ball mill and the tube mill. The reason for this form of construction is that it is found that, during, the operation of the mill, the largest balls accumulate at the large end of the cone and the smallest balls at the small end; there being a continuous gradation of size along the cone. If then the raw material is fed in at the large end of the mill and the ground product removed at the smaller end, the powder in its progression through the mill is ground by progressively small balls and in consequence the theoretical ideal of a constant ratio between ball size and particle size during grinding is, to some extent, attained.

The type of ball mill illustrated in Fig. 1.3, incorporates a peripheral discharge through line screens lining the cylindrical part of the mill. Heavy perforated plates protect the screens from injury and act as a lining for the tumbling charge; sometimes also the fine screen is further protected by coarse screens mounted directly inside it. This type of mill, which is often known as the Krupp mill, is of interest since it represents a very early type of mill which, with modifications, has retained its popularity. The Krupp mill is particularly suited to the grinding of soft materials since the rate of wear of the perforated liners is then not excessive. At this point it will perhaps be useful to discussthe factors upon which the choice between a ball a tube or a rod mill depends.

When a mill is used as a batch mill, the capacity of the mill is clearly limited to the quantity which can be handled manually; furthermore the mill is, as far as useful work is concerned, idle during the time required for loading and unloading the machine: the load factor thus being adversely affected. Clearly then, there will be a considerable gain in throughput, a saving in handling costs and improved load factor, if the mill operation is made continuous by feeding the material into the mill through one trunnion and withdrawing it either through the other trunnion or through discharge ports at the exit end of the mill body.

Since, however, the flow of powder through the mill is now continuous, it is necessary that the mill body is of such a length that the powder is in the mill for a time sufficiently long for the grinding to be carried to the required degree of fineness. This, in general, demands a mill body of considerable length, or continuous circulation with a classifier, and it is increased length which gives rise to the tube mill.

In the metallurgical industries very large tonnages have to be handled and, furthermore, an excess of fine material is undesirable since it often complicates subsequent treatment processes. In such applications a single-stage tube mill in circuit with a product classifier, by means of which the material which has reached optimum fineness is removed for transport to the subsequent processing and the oversize is returned to the mill for further grinding, is an obvious solution. Once continuous feed and a long mill body have been accepted, however, the overall grinding efficiency of the mill may be improved by fairly simple modifications.

As has already been mentioned; for optimum grinding conditions there is a fairly definite ratio of ball size to particle size and so the most efficient grinding process cannot be attained when a product with a large size range is present in the mill. If, however, a tube mill is divided into a number of compartments and the mean ball size of the grinding media decreases in each succeeding compartment; then the optimum ratio between ball size and particle size is more nearly maintained, and a better overall performance of the mill is achieved; this giving rise to the compartment mill shown in Fig. 1.6. The tube mill has the further advantage that, to some extent, the grinding characteristics of the mill are under control; for example, an increase in the size of the balls in the final chamber will reduce the rate of grinding of the finer fractions but will leave the rate of grinding of the coarser fractions sensibly unchanged and so the amount of coarse material in the final product will be reduced without any excessive overall increase in fineness.

The principal field of application of the rod mill is probably as an intermediate stage between the crushing plant and the ball mills, in the metallurgical industries. Thus, material between about 1-in. and 2-in. size may be reduced to about 6 mesh for feeding to the ball mills. Rod mills are, however, being used in closed circuit with a classifier to produce a product of less than about 48-mesh size, but such applications are unusual.

ball mill used in minerals processing plant | prominer (shanghai) mining technology co.,ltd

ball mill used in minerals processing plant | prominer (shanghai) mining technology co.,ltd

This ball mill is typically designed to grind mineral ores and other materials with different hardness, and it is widely used in different fields, such as ore dressing, building material field, chemical industry, etc. Due to the difference of its slurry discharging method, it is divided to two types: grid type ball mill and overflow type ball mill.

Compared with grid type ball mill, overflow type ball mill can grind materials finer even though its grinding time is usually longer. So it can make finer particle products. Hence the grid type ball mill is mainly used for primary stage of grinding while overflow type ball mill is mainly used for the secondary grinding.

Ball mill Advantages: 1Jack-up device, easy maintenance; 2The hydrostatic and hydrodynamic bearings ensure the smooth operation; 3Low speed transmission is easy for starting and maintenance; 4The oil-mist lubrication device guarantees reliable performance of bearings; 5The air clutch adopts the flexible start-up model./5According to the customer demand, manganese steel liner and wear-resistant rubber liner can be customized with good wear resistance, long service life and easy maintenance.

The grinding system uses either 'open circuit' or 'closed circuit'. In an open circuit system, the feed rate of materials is adjusted to achieve the desired fineness of the product. In a closed circuit system, coarse particles are separated from the finer ones and sent back for further grinding.

Prominer has been devoted to mineral processing industry for decades and specializes in mineral upgrading and deep processing. With expertise in the fields of mineral project development, mining, test study, engineering, technological processing.

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