Ganzhou Gelin Mining Machinery Co., Ltd. is an over 30 years experience expert manufacturing mining machines in China, covering an area of over 30,000 square meters, having more than 25 sets of heavy processing equipments and with an annual output of more than 2000 sets of mining machinery.We have international level & experienced engineer team and a strong R&D department and have been cooperating with domestic and oversea Scientific Research Institutes for many years. Our purpose is to track i...
A sectional view of the single-toggle type of jaw crusher is shown below.In one respect, the working principle and application of this machine are similar to all types of rock crushers, the movable jaw has its maximum movement at the top of the crushing chamber, and minimum movement at the discharge point. The motion is, however, a more complex one than the Dodge motion, being the resultant of the circular motion of the eccentric shaft at the top of the swing jaw. combined with the rocking action of the inclined toggle plate at the bottom of this jaw. The motion at the receiving opening is elliptical; at the discharge opening, it is a thin crescent, whose chord is inclined upwardly toward the stationary jaw. Thus, at all points in the crushing chamber, the motion has both, vertical and horizontal, components.
It will be noted that the motion is a rocking one. When the swing jaw is rising, it is opening, at the top, during the first half of the stroke, and closing during the second half, whereas the bottom of the jaw is closing during the entire up-stroke. A reversal of this motion occurs during the downstroke of the eccentric.
The horizontal component of motion (throw) at the discharge point of the single-toggle jaw crusher is greater than the throw of the Dodge crusher at that point; in fact, it is about three-fourths that of Blake machines of similar short-side receiving-opening dimensions. The combination of favorable crushing angle, and nonchoking jaw plates, used in this machine, promotes a much freer action through the choke zone than that in the Dodge crusher. Capacities compare very favorably with comparable sizes of the Blake machine with non-choking plates, and permissible discharge settings are finer. A table of ratings is given.
The single-toggle type jaw crusher has been developed extensively. Because of its simplicity, lightweight, moderate cost, and good capacity, it has found quite a wide field of application in portable crushing rigs. It also fits into the small, single-stage mining operation much better than the slower Dodge type. Some years since this type was developed with very wide openings for reduction crushing applications, but it was not able to seriously challenge the gyratory in this field, especially when the high-speed modern versions of the latter type were introduced.
Due to the pronounced vertical components of motion in the single-toggle machine, it is obvious that a wiping action takes place during the closing strokes; either, the swing jaw must slip on the material, or the material must slip along the stationary jaw. It is inevitable that such action should result in accelerated wear of the jaw plates; consequently, the single-toggle crusher is not an economical machine for reducing highly abrasive, or very hard, tough rock. Moreover, the large motion at the receiving opening greatly accentuates shocks incidental to handling the latter class of material, and the full impact of these shocks must be absorbed by the bearings in the top of the swing jaw.
The single-toggle machine, like the Dodge type, is capable of making a high ratio-of-reduction, a faculty which enables it to perform a single-stage reduction of hand-loaded, mine run ore to a suitable ball mill, or rod mill, feed.
Within the limits of its capacity, and size of receiving openings, it is admirably suited for such operations. Small gravel plant operations are also suited to this type of crusher, although it should not be used where the gravel deposit contains extremely hard boulders. The crusher is easy to adjust, and, in common with most machines of the jaw type, is a simple crusher to maintain.
As rock particles are compressed between the inclined faces of the mantle and concaves there is a tendency for them to slip upward. Slippage occurs in all crushers, even in ideal conditions. Only the particles weight and the friction between it and the crusher surfaces counteract this tendency. In particular, very hard rock tends to slip upward rather than break. Choke feeding this kind of material can overload the motor, leaving no option but to regulate the feed. Smaller particles, which weigh less, and harder particles, which are more resistant to breakage, will tend to slip more. Anything that reduces friction, such as spray water or feed moisture, will promote slippage.
Leading is a technique for measuring the gap between fixed and moveable jaws. The procedure is performed while the crusher is running empty. A lead plug is lowered on a lanyard to the choke point, then removed and measured to find out how much thickness remains after the crusher has compressed it. This measures the closed side setting. The open side setting is equal to this measurement plus the throw of the mantle. The minimum safe closed side setting depends on:
Blake (Double Toggle) Originally the standard jaw crusher used for primary and secondary crushing of hard, tough abrasive rocks. Also for sticky feeds. Relatively coarse slabby product, with minimum fines.
Overhead Pivot (Double Toggle) Similar applications to Blake. Overhead pivot; reduces rubbing on crusher faces, reduces choking, allows higher speeds and therefore higher capacities. Energy efficiency higher because jaw and charge not lifted during cycle.
Overhead Eccentric (Single Toggle) Originally restricted to sampler sizes by structural limitations. Now in the same size of Blake which it has tended to supersede, because overhead eccentric encourages feed and discharge, allowing higher speeds and capacity, but with higher wear and more attrition breakage and slightly lower energy efficiency. In addition as compared to an equivalent double toggle, they are cheaper and take up less floor space.
Since the jaw crusher was pioneered by Eli Whitney Blake in the 2nd quarter of the 1800s, many have twisted the Patent and come up with other types of jaw crushers in hopes of crushing rocks and stones more effectively. Those other types of jaw crusher inventors having given birth to 3 groups:
Heavy-duty crushing applications of hard-to-break, high Work Index rocks do prefer double-toggle jaw crushers as they are heavier in fabrication. A double-toggle jaw crusher outweighs the single-toggle by a factor of 2X and well as costs more in capital for the same duty. To perform its trade-off evaluation, the engineering and design firm will analyze technical factors such as:
1. Proper selection of the jaws. 2. Proper feed gradation. 3. Controlled feed rate. 4. Sufficient feeder capacity and width. 5. Adequate crusher discharge area. 6. Discharge conveyor sized to convey maximum crusher capacity.
Although the image below is of a single-toggle, it illustrates the shims used to make minor setting changes are made to the crusher by adding or removing them in the small space between the crushers mainframe and the rea toggle block.
The jaw crusher discharge opening is the distance from the valley between corrugations on one jaw to the top of the mating corrugation on the other jaw. The crusher discharge opening governs the size of finished material produced by the crusher.
Crusher must be adjusted when empty and stopped. Never close crusher discharge opening to less than minimum opening. Closing crusher opening to less than recommended will reduce the capacity of crusher and cause premature failure of shaft and bearing assembly.
To compensate for wear on toggle plate, toggle seat, pitman toggle seat, and jaws additional shims must be inserted to maintain the same crusher opening. The setting adjustment system is designed to compensate for jaw plate wear and to change the CSS (closed side setting) of the jaw crusher. The setting adjustment system is built into the back frame end.
Here also the toggle is kept in place by a compression spring. Large CSS adjustments are made to the jaw crusher by modifying the length of the toggle. Again, shims allow for minor gap adjustments as they are inserted between the mainframe and the toggle block.
is done considering the maximum rock-lump or large stone expected to be crushed and also includes the TPH tonnage rate needing to be crushed. In sizing, we not that jaw crushers will only have around 75% availability and extra sizing should permit this downtime.
As a rule, the maximum stone-lump dimension need not exceed 80% of the jaw crushers gape. For intense, a 59 x 79 machine should not see rocks larger than 80 x 59/100 = 47 or 1.2 meters across. Miners being miners, it is a certainty during day-to-day operation, the crusher will see oversized ore but is should be fine and pass-thru if no bridging takes place.
It will be seen that the pitman (226) is suspended from an eccentric on the flywheel shaft and consequently moves up and down as the latter revolves, forcing the toggle plates outwards at each revolution. The seating (234) of the rear toggle plate (239) is fixed to the crusher frame; the bottom of the swing jaw (214) is therefore pushed forward each time the pitman rises, a tension rod (245) fitted with a spring (247) being used to bring it back as the pitman falls. Thus at each revolution of the flywheel the movable jaw crushes any lump of ore once against the stationary jaw (212) allowing it to fall as it swings back on the return half-stroke until eventually the pieces have been broken small enough to drop out. It follows that the size to which the ore is crushed.
The jaw crusher is not so efficient a machine as the gyratory crusher described in the next paragraph, the chief reason for this being that its crushing action is confined to the forward stroke of the jaw only, whereas the gyratory crusher does useful work during the whole of its revolution. In addition, the jaw crusher cannot be choke-fed, as can the other machine, with the result that it is difficult to keep it working at its full capacity that is, at maximum efficiency.
Tables 5 and 6 give particulars of different sizes of jaw crushers. The capacity figures are based on ore weighing 100 lb. per cubic foot; for a heavier ore, the figures should be increased in direct proportion to its weight in pounds per cubic foot.
The JAW crusher and the GYRATORY crusher have similarities that put them into the same class of crusher. They both have the same crushing speed, 100 to 200 R.P.M. They both break the ore by compression force. And lastly, they both are able to crush the same size of ore.
In spite of their similarities, each crusher design has its own limitations and advantages that differ from the other one. A Gyratory crusher can be fed from two sides and is able to handle ore that tends to slab. Its design allows a higher-speed motor with a higher reduction ratio between the motor and the crushing surface. This means a dollar saving in energy costs.
A Jaw crusher on the other hand requires an Ely wheel to store energy. The box frame construction of this type of crusher also allows it to handle tougher ore. This design restricts the feeding of the crusher to one side only.
The ore enters from the top and the swing jaw squeezes it against the stationary jaw until it breaks. The broken ore then falls through the crusher to be taken away by a conveyor that is under the crusher.Although the jaws do the work, the real heart of this crusher is the TOGGLE PLATES, the PITMAN, and the PLY WHEEL.
These jaw crushers are ideal forsmall properties and they are of the high capacity forced feed design.On this first Forced Feed Jaw Crusher, the mainframe and bumper are cast of special alloy iron and the initial cost is low. The frame is ribbed both vertically and horizontally to give maximum strength with minimum weight. The bumper is ruggedly constructed to withstand tremendous shock loads. Steel bumper can be furnished if desired. The side bearings are bronze; the bumper bearings are of the antifriction type.
This bearing arrangement adds both strength and ease of movement. The jaw plates and cheek plates are reversible and are of the best-grade manganese steel. The jaw opening is controlled by the position of an adjustable wedge block. The crusher is usually driven by a V-to-V belt drive, but it can be arranged for either V-to-flat or fiat belt drive. The 8x10 size utilizes a split frame and maybe packed for muleback transportation. Cast steel frames can be furnished to obtain maximum durability.
This second type of forced feed rock crusher is similar in design to the Type H listed above except for having a frame and bumper made of cast steel. This steel construction makes the unit lighter per unit of size and adds considerable strength. The bearings are all of the special design; they are bronze and will stand continuous service without any danger of failure. The jaw and cheek plates are manganese steel; and are completely reversible, thus adding to their wearing life. The jaw opening is controlled by the position of an adjustable wedge block. The crushers are usually driven by V-to-V but can be arranged for V-to-flat and belt drive. The 5x6 size and the 8x10 size can be made with sectionalized frame for muleback transportation. This crusher is ideal for strenuous conditions. Consider a multi jaw crusher.
Some jaw crushers are on-floor, some aboveground, and others underground. This in many countries, and crushing many kinds of ore. The Traylor Bulldog Jaw crusher has enjoyed world wide esteem as a hard-working, profit-producing, full-proof, and trouble-free breaker since the day of its introduction, nearly twenty years ago. To be modern and get the most out of your crushing dollars, youll need the Building breaker. Wed value the privilege of telling you why by letter, through our bulletins, or in person. Write us now today -for a Blake crusher with curved jaw plates that crush finer and step up production.
When a machine has such a reputation for excellence that buyers have confidence in its ability to justify its purchase, IT MUST BE GOOD! Take the Type G Traylor Jaw Crusher, for instance. The engineers and operators of many great mining companies know from satisfying experience that this machine delivers a full measure of service and yields extra profits. So they specify it in full confidence and the purchase is made without the usual reluctance to lay out good money for a new machine.
The success of the Type G Traylor Jaw Crusheris due to several characteristics. It is (1) STRONG almost to superfluity, being built of steel throughout; it is (2) FOOL-PROOF, being provided with our patented Safety Device which prevents breakage due to tramp iron or other causes of jamming; it is (3) ECONOMICAL to operate and maintain, being fitted with our well-known patented Bulldog Pitman and Toggle System, which saves power and wear by minimizing frictionpower that is employed to deliver increased production; it is (4) CONVENIENT to transport and erect in crowded or not easily accessible locations because it is sectionalized to meet highly restrictive conditions.
Whenever mining men need a crusher that is thoroughly reliable and big producer (which is of all time) they almost invariably think first of a Traylor Type G Jaw Crusher. By experience, they know that this machine has built into it the four essentials to satisfaction and profit- strength, foolproofness, economy, and convenience.
Maximum STRENGTH lies in the liberal design and the steel of which crushers parts are made-cast steel frame, Swing Jaw, Pitman Cap and Toggles, steel Shafts and Pitman rods and manganese steel Jaw Plates and Cheek Plates. FOOLPROOFNESS is provided by our patented and time-tested safety Device which prevents breakage due to packing or tramp iron. ECONOMY is assured by our well-known Bulldog Pitman and Toggle System, which saves power and wear by minimizing friction, the power that is used to deliver greater productivity. CONVENIENCE in transportation and erection in crowded or not easily accessible locations is planned for in advance by sectionalisation to meet any restrictive conditions.
Many of the worlds greatest mining companies have standardized upon the Traylor Type G Jaw Crusher. Most of them have reordered, some of them several times. What this crusher is doing for them in the way of earning extra dollars through increased production and lowered costs, it will do for you! Investigate it closely. The more closely you do, the better youll like it.
The belowimage shows a sectional view of a typical gyratory crusher. This type of machine is, by virtue of chronological priority, known as the standard gyratory crusher. Although it incorporates many refinements in design, it is fundamentally the same crusher that first bore the name of gyratory; its crushing chamber is very much the same shape; the motion is identically the same, and the method of transmitting power from belt to crushing head is similar. It is an interesting fact that the same similarity in essential features of design exists in the case of the standard, or Blake type, jaw crusher, which is something in the way of a tribute to the inspiration and mechanical ability of the men who originated these machines.
Essentially, the gyratory crusher consists of a heavy cast-iron, or steel, frame which includes in its lower part an actuating mechanism (eccentric and driving gears), and in its upper part a cone-shaped crushing chamber, lined with wear-resisting plates (concaves). Spanning the crushing chamber across its top is a steady-rest (spider), containing a machined journal which fixes the position of the upper end of the main shaft. The active crushing member consists of the main shaft and its crushing head, or head center and mantle. This assembly is suspended in the spider journal by means of a heavy nut which, in all but the very large machines, is arranged for a certain amount of vertical adjustment of the shaft and head. At its lower end the main shaft passes through the babbitted eccentric journal, which offsets the lower end of the shaft with respect to the centerline of the crusher. Thus, when the eccentric is rotated by its gear train, the lower end of the main shaft is caused to gyrate (oscillate in a small circular path), and the crushing head, likewise, gyrates within the crushing chamber, progressively approaching, and receding from, each element of the cone-shaped inner surface.
The action of the gyratory crusher, and of the other member of the reciprocating pressure family, the jaw crusher, is fundamentally a simple one, but as will be seen a great deal of thought and some very progressive engineering has been expended upon the design of crushing chambers to increase capacities and to permit the use of closer discharge settings for secondary and fine-reduction crushing (various crusher types).
Referring to the table, always available from the manufacturer, it will be noted that standard gyratory crushers are manufactured in commercial sizes ranging from 8 to 60 receiving openings. Capacities are listed, for minimum and maximum open-side discharge settings, in short tons per hour, and the horsepower requirements for soft and hard materials are listed for each size. The capacities, and the minimum settings, are based upon the use of standard (straight-face) concaves.
Primary gyratory crushers are designated by two numbers. These are the size of the feed opening (in inches) and the diameter of the mantle at its base (in inches). A 60~x~89 crusher would have an opening dimension of 60 inches (152 cm) and a diameter across the base of the mantle of 89 inches (226 cm).
To stand up under the extremely rugged work of reducing hard and tough rock and ore, and in doing so to maintain reasonably true alignment of its running component, the crushermust necessarily be of massive and rigid proportions, rigidity being of equal importance to ultimate strength. Regardless of the tensile strength of the metal used in the main frame, top shell, and spider, these parts must be made with walls and ribs thick enough to provide this rigidity. Therefore it is practicable to use close-grained cast iron, and special high-test mixtures of cast iron, for these parts, if the machine is intended for crushing soft or medium materials. When very hard and tough materials are to be crushed, the machine is usually strengthened by substituting cast steel in one or more of its parts.
Wearing parts in the gyratory crusher may be either chilled cast iron or manganese steel, depending on the character of the material to be crushed and the particular class of service for which the machine is intended. Standard crushers, in the small and medium sizes, are customarily fitted with chilled-iron head and concaves for crushing soft and medium limestone and materials of similar hardness and abrasiveness, because its relatively low first cost and excellent wearing qualities make it the most economical material to use when the service is not too severe. Manganese steel, which combines extreme toughness with unsurpassed wear-resistance, is the universal choice for crushing hard, tough rock regardless of the class of service or type of crusher. Even though the rock be quite soft and non-abrasive, it is general practice to use manganese steel concaves in the larger sizes of primary crushers because of the shocks attendant upon handling large and heavy pieces of rock.
The primary rockbreaker most commonly used in large plants is the gyratory crusher, of which a typical section is shown in Fig. 5.It consists essentially of a gyrating crushing head (521) working inside a crushing bowl (522) which is fixed to the frame (501).
Thecrushing head is carried on a short solid main shaft (515) suspended from the spider (502) by a nut (513) ; the nut fits into the seating of a sleeve (514) which fixes its position in relation to the spider and, therefore, to the frame (501). The lower part of the main shaft fits into a sleeve (530) set in an eccentric (527), to which is keyed the bevel driving gear (528) ; the bevel pinion (533) is similarly fastened to the countershaft (535) and engages with the bevel gear. The whole of this driving assembly is protected from grit and dust by means of a dust seal (524), (525), and (526).
The countershaft carries the driving pulley, and as it revolves it causes the eccentric to rotate ; as it rotates the main shaft gyrates and with it the crushing head ; the top of the shaft at the point of suspension has practically no movement. Although the motion of the head is gyratory, the main shaft is free to rotate in the eccentric and it actually revolves slowly in relation to the bowl, thus equalizing the wear on the mantle (519) which lines the head and on the concave liners (522 and 523) which comprise the bowl. Both mantle and bowl liners are usually made of manganese steel. The suspension nut (513) is adjustable and enables the crushing head and main shaft to be raised in relation to the bowl to compensate for wear. The size of the product is determined by the distance between the bottom edges of the crushing head and the bowl, in the position when they are farthest apart.
The crushing action is much the same in principle as that of a jaw crusher, the lumps of ore being pinched and broken between the crushing head and the bowl instead of between two jaws. The main point ofdifference between the two types is that the gyratory crusher does effective work during the whole of the travel of the head, whereas the other only crushes during the forward stroke. The gyratory crusher is thereforethe more efficient machine, provided that the bowl can be kept full, a condition which is, as a rule, easy to maintain because it is quite safe to bury the head in a pile of ore.
Tables 7 and 8 give particulars of different sizes of gyratory crushers. As in the previous paragraph, the capacity figures are based on material weighing 100 lb. per cubic foot and should be increased in direct proportion for heavier ores.
Primary and secondary gyratory crushers, including the cone crusher, can be directly connected to slow speed motors if desired, but the standard method of drive is still by belt and pulley. Jaw crushers must be belt-driven.
An efficient substitute for the flat belt in all cases is the Texrope drive, which consists of a number of V-shaped endless rubber belts running on special grooved pulleys. The grip of these belts is so great that the distance between the pulley centres can be reduced to about 30% of that required for a flat belt. This results not only in a saving of space but also in greater safety, since the drive is easier to protect and there is no danger of an accident such as might occur if a long belt were to pull through its fasteners. Moreover, the short drive makes it possible for any stretch to be taken up by moving the motor back on its rails without the necessity of cutting and rejoining the belts. The flexibility and ease of maintenance of the Tex-rope drive makes it very suitable for crushing machines.
LOW OPERATING COSTS Vertical adjustment compensates for wear on crushing surfaces (also maintains product uniformity). Oiling system provides proper lubrication throughout, including spider. Effective dust seal prevents dust infiltration to moving parts. Long life bearings, easy to replace.
Strength, of course, makes an all-important contribution to the rugged heavy duty service and day-in, day-out dependability demanded of a crusher. However, strength does not necessarily mean excessive weight. The metals and alloys used in construction and the distribution of weight are actually the determining factors in the strength of a gyratory crusher.
MAINSHAFT ASSEMBLY mainshaft forged steel; annealed quenched and tempered. Tapered to gauge for head center fit. Head center of cast steel. Head mantle of manganese steel. Mainshaft sleeve shrunk on mainshaft to provide renewable wearing surface on spider bearing.
Gyratory crusher advanced design includes the placing of circumferential ribs around the top and bottom shells. These integrally cast reinforcing rings prevent distortion provide the rigidity necessary to maintain true alignment of running parts.
Hollow box construction of the cast steel spider affords maximum strength with the least amount of feed interference. Arms are cast integrally with the heavy outer rim. Crushing stresses are transmitted to the rim, which is taper-fitted to the top shell. Because spider and top shell are interlocked, they reinforce each other to provide maximum stability and rigidity.
The bottom shell is the foundation of the crusher. It must be strong enough not only to support the weight of the crusher, but to withstand extreme crushing stresses (most stresses terminate here) strong enough to protect vital mechanism the eccentric, gears and countershaft assembly housed in the bottom shell. In the Gyratory crusher, bottom discharge design makes possible a compact, squat structure of simplified design and comparatively high strength. Supplementing the strength of the bottom shell are the previously described circumferential ribs. Crushing stresses are transmitted directly to these reinforcing members through three radial arms.
Because the mainshaft does the actual crushing, it must literally possess crushing strength. In the Gyratory crusher, the eccentric is located directly below the crushing head. This design permits the use of a short, rigid mainshaft a mainshaft that will withstand the strain of severe service.
Flexibility is the keynote of the Gyratory crusher efficiency and economy. While your particular installation is designed to best meet your specific and immediate requirements, built-in flexibility permits adaptation to changing operating conditions anytime in the future.
A Gyratory crusher not only affords a maximum capacity-to-size ratio, but provides the variable factors which facilitate increasing or decreasing capacity as the need arises. Flexibility in a Gyratory crusher also permits compensation for wear and assures product uniformity.
In the Gyratory crusher, the use of spiral bevel gears instead of spur gears makes possible the broad range of speeds conducive to meeting varying capacity demands. Because the Gyratory crusher is equipped with an external oiling system, speed may be reduced as much as desired or required. Adequate lubrication is supplied at even the lowest speeds, because the flow of oil is not relative to the crushers operating speed as is the case with an internal system.
With a primary gyratory crusher running at a given countershaft speed, capacity is increased as eccentricity is increased. At a given eccentricity, greater capacity results from higher countershaft speeds. Conversely, reducing either the speed or eccentricity reduces capacity.
Another high capacity characteristic of the Gyratory crusher is a large diameter crushing head. Because the area of discharge opening is directly proportionate to head diameter, high capacities result.
VARIABLE INITIAL SETTINGS The contour of the crushing chamber at the bottom is designed to afford various initial settings without changing the angle of the nip. This is accomplished by installing lower tier concaves of the shape and thickness for the desired setting and capacity.
HOW SIZES ARE DESIGNATED The numerical size designation of Gyratory crushers represents the feed opening and the maximum diameter of the crushing head. For example, a 60-109 Gyratory crusher has a 60-inch receiving opening and an 109-inch maximum diameter crushing head.
ELIMINATES DIAPHRAGM In a gyratory crusher with aside discharge, sticky materials may pack on the diaphragm and eventually cause considerable damage. Thestraight down discharge of the Gyratory crusher is a design simplification that eliminates the diaphragm and itsmaintenance problems.
CONTRIBUTES TO BALANCED CIRCUIT The adaptabilityof a primary crusher to a large extent dictates the plantflowsheet the initial and overall operating costs of subsequent equipment. With a Gyratory primary crusher,these costs are kept at a minimum because the entirecrushing circuit remains in balance. The concrete foundation may be modified for use as a surge bin. This storagecapacity permits controlling the flow of material throughthe plant. Secondary and tertiary crushers, vibrating screens, etc. may be installed in size ranges and types tomeet the requirements of a constant tonnage. For thosefew installations where a side discharge is essential, a discharge spout can be furnished. Another factor in maintaining a balanced circuit is the vertical adjustment(pages 12 and 13) which permits retaining the initial discharge setting by compensating for wear on mantle andconcaves. Related equipment need not be readjusted because of variations of feed size from the primary crusher.
In the Gyratory crusher, the original discharge setting may be maintained for the life of a single set of alloy crushing surfaces with only one resetting of concaves. Raising the mainshaft compensates for wear onconcaves and mantle. This simplified vertical adjustment cuts resetting time facilitates holding product size.
The threaded mainshaft is held in and supported from the spider hub. (See illustration at lower left.) A vertical adjustment range of from 6 inches to approximately 11 inches is possible, depending upon the size of the machine. The original discharge setting can be maintained until the combined wear of mantle and concaves is about one-third of the vertical adjustment.
A cast steel, split adjusting nut with a collar issupported on a two-piece thrust bearing in the spider hub. The nut is threaded for the mainshaft. The outside of the nut is tapered, with the large diameter at the top. The weight of the head and shaft draws the nut down in its tapered seat in the collar to form a self-clamping nut. Desired setting is achieved by positioning split nut in the proper location on the threaded portion of the mainshaft.
The Gyratory crusher is also available with a Hydroset mechanism a hydraulic method of vertical adjustment. With the Hydroset mechanism, compensation for wear and product size control is a one- man, one-minute operation. The Hydroset mechanism consists of a motor-driven gear pump operated by push button.
The accompanying drawings show the simplicity of Hydroset design. The mainshaft assembly is supported on a hydraulic jack. When oil is pumped into the jack, the mainshaft is raised compensating for mantle and concave wear or providing a closer setting. When oil is removed from jack, the mainshaft is lowered and a coarser setting results.
Since the mainshaft assembly is supported on a hydraulic jack, its position with respect to the concaves, and therefore the crusher setting, is controlledby the amount of oil in the hydraulic cylinder.
Oil pressure is maintained in the hydraulic cylinder below the mainshaft by a highly effective chevron packing. The oil supply of the Hydroset mechanism functions independently of the crushers lubrication system.
If a Gyratory crusher equipped with Hydroset mechanism stops under load, the mainshaft may be lowered to facilitate clearing of the crushing chamber by merely pumping oil out of the cylinder. Only under extreme conditions is it necessary to dig out. When the cause of the stoppage is remedied, the oil is pumped back into the cylinder quickly, returning the mainshaft assembly to its initial position.
STEP BEARING consists of bronze mainshaft step, bronze piston wearing plate, and an alloy steel washer between the two. Washer is drilled for oil cooling lubrication. Bearing surfaces are grooved to permit oil distribution.
Utilizing pool lubrication, a gun-type fitting in the spider arm makes it easy to oil the spider bearing. A garter-type oil seal in the bottom of the bearing retains oil. Being flexible, the seal compensates for movement of crusher mainshaft.
The countershaft assembly is an anti-friction, pool-lubricated unit. Both ends of the bearing housing are sealed by garter-type spring oil seals which: (1) keep dust from anti-friction bearings; (2) separate pinion- shaft bearing lubricant from oil lubricating the eccentric and gears.
Getting the most out of a crusher in performance and capacity depends largely upon positive lubrication. And positive lubrication means more than just adequate oil lubrication. It also entails conditioning oil for maximum lubricating efficiency.
The Gyratory crusher is equipped with an externally located, fully automatic lubricating system. Positive and constant lubrication is maintained at all speeds even at the slowest speed. If desired, oil may be circulated through bearings of Gyratory crusher during shutdown periods.
A gear pump circulates oil from storage tank, through crusher and back. Each time oil is pumped to the crusher, it passes through the filter and cooler. The cleaned, cool oil lubricates the step bearing (in Hydroset mechanism only), the eccentric wearing plate and the inner eccentric bearing. At the top of the bearing, most of the oil flows through ports in the eccentric to the outer eccentric bearing. Theoil then flows down the outer eccentric bearing and lubricates the gear and pinion before it is returned to storage. The overflow oil which may have become contaminated is returned immediately to the oil conditioning tank. It does not contact any other wearing parts within the crusher.
The oil conditioning system may be modified to meet your particular applications. In cold climates immersion heaters are installed in the storage tank to preheat oil. This arrangement permits circulating warm oil through the crusher during shutdown periods. A thermostatic control turns heater on and off. Only in a crusher specifically designed for external oiling is it possible to circulate warm oil when the crusher is stopped.
An added measure of safety is providedby the oil conditioning system. Foreignmaterial is removed by pumping warm oilthrough a mechanical filter. After oil isfiltered, it flows through a condenser-type cooler before it is returned to the crusher.
An oil flow switch provides automatic protection against possible damage caused by oil system failure. This switch stops the crusher immediately if oil flow is insufficient for proper lubrication. Interlocks between pump motor and crusher prevent starting crusher before oil circulation begins.
In addition to its other advantages, the externally located oil conditioning system is easy to service. The unit consists of (A) an oil storage tank, (B) a motor-driven gear pump, (C) a pressure- type filter, and (D) a condenser-type cooler.
In the gyratory crusher, expensive castings are protected by replaceable parts. Rim and arm liners protect the spider from wear. Bottom shell liners and shields provide protection below the crushing chamber. An alloy steel shaft sleeve protects the mainshaft in the spider bearing. The eccentric sleeve and bushing are easily replaced when worn.
Because all parts are readily accessible and removable, down time is kept to a minimum. For example, the countershaft assembly is removed as a unit and can be taken to your machine shop for convenient servicing. Eccentric bearings are bronze bushings. Because bronze is used, the need for babbitt mandrels and melting facilities is eliminated.
Sealing out dirt and dust and their equipment-destroying abrasive action results in obvious maintenance economies. The type of dust seal used in the gyratory crusher is the most reliable and effective device ever developed for preventing excessive wear caused by dirt and dust.
In the gyratory crusher, a synthetic, self-lubricating, light-weight ring is used as a dust seal. The ring is enclosed between a dust collar bolted to the bottom shell and a recess in the bottom of the head center. Regardless of the eccentric throw and vertical positioning, the ring maintains its contact with the outer periphery of the dust collar. Because of its light weight and self-lubricating characteristics, wear on this ring is negligible.
Provisions have been made on the gyratory crusher for the introduction of low pressure air to the dust seal chamber. This internal pressure, which can be obtained through the use of a small low pressure blower, creates an outward flow of air through the dust seal. This prevents an inward flow of abrasive dirt and dust. The combination of a highly effective sealing ring and the utilization of internal air pressure protects the eccentric and gears from destructive infiltration even under the most severe conditions. When required, this additional protection is supplied at a nominal additional cost.
All of the operating advantages all of the engineering and construction features described in this bulletin are found in both the primary and secondary gyratory crushers. Of course, certain modifications have been made to efficiently accomplish the tough, rugged job of secondary crushing. For instance, the secondary gyratory crusher has been engineered to accommodate the greater horsepower requirement of secondary crushing. Increased strength and durability have been built into all components.
In the past, primary crushers had to be set extremely close in order to provide an acceptable feed for secondary crushers. As a result, primary crushers were penalized by reduced capacity and excessive maintenance. The secondary gyratory crusher was engineered to solve this problem.
Anticipating product size variations, Allis-Chalmers has designed the secondary crusher with a large feed opening one large enough to accept oversized materials. This design feature is particularly advantageous when the secondary gyratory crusher follows a primary crusher that has no vertical adjustment for wear.
A large diameter crushing head along with tailored-to-your-operation design results in big capacity. An acute angle in the crushing chamber and a long parallel zone facilitate precision setting assure a cubical, well graded product distributes even the normal wear throughout the crushing chamber.
1. Spider cap 2. Spider 3. Hour glass bushing 4. Spider bearing oil seal 5. Spider bearing oil seal retainer 6. Spider bearing oil seal retainer screws 7. Spider joint bolts 8. Spider joint bolt nuts 9. Spider joint bolt lock nuts 10. Spider arm shield 11. Spider arm shield bolts 12. Spider arm shield bolt nuts 13. Center spider rim liners (not shown) 14. End spider rim liners 15. Rim liner bolts 16. Rim liner bolt nuts 17. Spider bearing spherical support ring 18. Spider bearing spherical support ring seat 19. Spider lubricating hose bushing 20. Spider lubricating hose 21. Spider lubricating hose bracket 22. Spider lubricating hose grease fitting 23. Spider lubricating hose bracket bolts 24. Spider joint studs (not shown) 26. Mainshaft thrust ring 27. Mainshaft thrust ring bolts 31. Top shell 32. Concave support ring 33. Upper concaves 34. Upper middle concaves 36. Lower middle concaves 37. Lower concaves 43. Bottom shell 44. Bottom shell joint bolts 45. Bottom shell joint bolt nuts 46. Bottom shell joint bolt lock nuts 47. Bottom shell bushing 48. Bottom shell bushing key 49. Bottom shell bushing clamp plate 50. Bottom shell bushing clamp plate bolts 51. Bottom shell front arm liners 52. Bottom shell rear arm liners 53. Bottom shell side liners 54. Bottom shell hub liners 55. Dust collar 56. Dust collar cap screws 57. Dust collar gasket 63. Bottom plate 64. Bottom plate studs 65. Bottom plate stud nuts 66. Bottom plate stud lock nuts 67. Bottom plate dowel pin 68. Bottom plate drain plug 69. Bottom plate gasket 95. Eccentric 96. Eccentric sleeve 97. Eccentric sleeve key 98. Bevel gear 99. Bevel gear key 100. Bevel gear key cap screws 101. Eccentric wearing plate 107. Mainshaft 108. Head center 109. Mantle lower section 110. Mantle upper section 111. Head nut 112. Dowel pin (for keying head nut to mantle) 113. Mainshaft sleeve 114. Adjusting nut 115. Adjusting nut collar 116. Enclosed ring type dust seal sealing ring 117. Enclosed ring type dust seal retaining ring 118. Enclosed ring type dust seal bolts 119. Adjusting nut tie bar 120. Adjusting nut tie bar bolts 121. Adjusting nut key 124. Pinion bearing housing 125. Pinion bearing housing gasket 126. Pinion bearing housing studs 127. Pinion bearing housing stud nuts 128. Pinion bearing housing stud lock nuts 129. Pinion bearing housing dowel pin 130. Pinion bearing housing oil drain plug 131. Pinion bearing housing oil level plug (not shown) 132. Pinion bearing housing oil filler plug 133. Pinionshaft 134. Drive sheave and bushing 135. Drive sheave key 136. Pinion shaft lock nut spacer 137. Pinion shaft lock nut spacer lockwasher 138. Pinion shaft lock nut spacer lockwasher gasket 139. Pinion bearing seal plate 140. Pinion bearing oil seal 141. Pinion bearing seal plate gaskets 142. Pinion bearing seal plate bolts 143. Pinionshaft outer bearing 144. Pinionshaft inner bearing 145. Pinionshaft bearing spacing collar 146. Pinionshaft bearing spacing collar gasket 147. Pinion 148. Pinion key 149. Pinion retainer plate 150. Pinion retainer plate bolts
In the dimension charts above, the first number in each size classification designates the size of the receiving opening in inches. The second number is the largest diameter of the mantle in inches. Primary crushers having the same mantle diameter use the same size bottom shell, gears, eccentrics and countershaft assemblies.
Secondary crushers use the same size bottom shells as certain size primary crushers, but different size top shells, mainshaft and spider assemblies. The 30-70 secondary gyratory crusher uses the bottom shell of the 42-65 primary crusher; the 24-60 secondary uses the 30-55 primary bottom shell.
Capacities given here are based on field data under average quarry conditions when crushing dry friable material equivalent to limestone. Because conditions of stone and methods of operation vary, capacities given are approximate only.
Where no capacity data is given the crusher is under development.Figures under Maximum Horsepower are correct only for throw and pinion Rpm given above. When speed is reduced, Maximum Horsepower must also be reduced proportionately.
This graph is based on customary practice and is principally a guide. Size of crusher may vary considerably with different materials, depending upon stratification, blockiness, quarry methods and size of quarry trucks. Pieces that cannot be handled by crusher without bridging should be broken in the quarry.
The screen analysis of the product from any crusher will vary widely, depending upon the character of the material, quarry conditions, and the amount of fines or product size in the initial feed at the time
the sample is taken. These factors should be taken into consideration when estimating the screen analysis of the crusher product. Product gradation curves based on many actual screen analyses have been prepared which can be used for estimating.
The crusher discharge opening on the open side will govern the product gradation from a crusher if corrected to take into consideration quarry or mine conditions, particularly as to the amount of fines in the crusher feed. The tabulation at the left is basedon an average of many screen analyses and gives the approximate percentage of product equal to the open side setting of the crusher. Its actual use when the feed conditions are definitely known should be corrected to take care of these conditions, particularly insofar as fines or product size in the feed are concerned. The curves on these pages have been prepared giving the approximate screen analysis of the crusher product and should be used in conjunction with Table I
Table I shows 90% of product should pass a 6-inch square opening flat testing sieve. Using the 90% vertical line on Table II, follow it up to the horizontal line of 6 inches. Follow the nearest curve to the intersection, and using this curve you will get the following approximate screen analysis.
Until recently, there has been no way of accurately determining the power required for agiven crushing operation. With little or no factualoperating data correlated into useful form, it wasdifficult even for the most experienced operators toarrive at a correct size crusher or a proper size crusher motor to do a given job.
The correlation of all this factual material, from extensive field operating data and laboratory data covering wide varieties of material, ranges of reduction sizes, and types of equipment, made it possible to establish a consistent common factor known asthe Work Index for accurately determining the power required for crushing.
In the Work Index method, frequently referred to as the Bond method, the Work Index is actually the total work input in kwhr per short ton required to reduce a given material from theoretically infinite particle size to 80% passing 100 microns or approximately 67% passing 200 mesh. Knowing the Work Index, you need only apply the given equation to determine power input required. The calculated power input enables you to select the proper crusher.
In order to simplify the selection of a crusher by the Work Index method, the following form has been developed. References below the form explain the various parts of the calculation, and, immediately below, a complete example is worked out.
REFERENCE I Average Impact. As noted, the Work Index is determined from the average impact value and the specific gravity of the material being crushed. The impact value and Work Index can be determined in the Processing Machinery Laboratory, or these values can be determined from a comparable operation in the field. Acomplete listing of Work Indexes of materials which have been tested in the laboratory.
REFERENCE II Feed Size. In the case of a primary crusher this may be somewhat difficult to obtain. Experience indicates, however, that in most cases 80% of the feed size will pass a square opening equal to from half to two-thirds of the crusher receiving opening.
A crushed stone producer desires a primary crusher to handle the product from a 3-yard shovel at an average rate of 350 tph. The rated capacity of the crusher must, of course, be greater than this because of inevitable quarrying and crushing delays. A crusher setting of 5 in. on the open side is desired because of following equipment and the requirements for stone.
MATERIAL: Limestone WORK INDEX 10.7 CRUSHER: 42-65 Primary gyratory Open Side Setting: 5; Eccentric Throw: 1 Recommended Operating Speed; 400 Rpm (Approximately 80% of Maximum Speed) Capacity at Recommended Speed: 438 Short Ton/Hour Maximum Horsepower Allowable at Selected Throw and Speed: 213 Horsepower. FEED SIZE: (F) 80% Passes 28 (66% of Feed Opening) F 711,000 Microns F = 842 PRODUCT SIZE: (P) 80% Passes 4, P = 108,000 Microns P = 328 F P = 514 HORSEPOWER/SHORT TON = 10.7 x 13.4 x 514/842 x 328 = .267 .267 Horsepower/Short Ton x438 Short Tons/Hour Capacity = 117Horsepower Required RECOMMENDED MOTOR SIZE: 150 Horsepower Motor.
Tabulated data presented has been compiled from tests made in the Allis-Chalmers Research Laboratory. This data is a cross section of impact and compressive strength tests made on hundreds of different rock samples for customers in the U.S. and abroad.
Ten or more representative pieces of broken stone, each of which passes a square opening three inches on a side and will not pass a two-inch square, are selected and broken individually between two 30-lb pendulum hammers. The hammers are raised by an equal amount and released simultaneously. This is repeated with successively greater angles of fall until the specimen breaks. Its impact strength is the average foot-pounds of energy represented by the breaking fall divided by the thickness in inches. The average impact strength is the average foot-pounds per inch required to break the ten or more pieces, and the maximum is the foot-pounds per inch required to break the hardest piece, the highest value obtained.
The compressive strengths of many materials have been measured in the Laboratory by cutting samples into one-inch cubes which are then broken under slow compression in a Southwark compression tester. This indicates the compressive strength in pounds per square inch.
The correlation between the compressive strengthand the impact crushing strength is inconsistent, and experiencehas shown that theimpact strength is abetter criterion of theactual resistance tocrushing. The impactdevice more nearly approaches actual crusher operation, both invelocity of impact andin the fact that broken stone is used intesting.
The average impactcrushing strength isan indication of theenergy required forcrushing, while themaximum compression values indicate the danger of crusher breakage and the type of construction necessary. Crusher capacities do not vary greatly with the impact strength. There is a capacity increase of less than 10% from the hardest to the softest stone, where packing is not a factor.
A Gold Shaking Table are basically low-capacity machines used as last step in the gold upgrading process. Theshakingtable is a thin film, shear flow process equipment, that separatesparticlegrains of its feed material based on thedifferences in their specific gravity, density, size and shape. Mineral rich particles, from light to heavy and fine to coarse will be sorted by net effective weight. Finely crushed or ground ore material goes as feed mixed with water to form a pulp (mud) andfed as slurry of an average about 2025% of solids by weight onto the highest point of the table deck. The gold tables deck hasa reciprocal movement along its main axis that is given using a vibrator or an eccentric head motion. The table surface is manufactured and fitted with several tapered strips called riffles or grooves, often made with of yellow pine (way back in time that is), low-density polythene or aluminum surfacing.Shaking tables and other thin film separating plant recover finely divided gold under conditions of subcritical laminar and supercritical laminar regimes of flow, which may occur only where there is a very thin depth of fluid.
Agold shaking tables riffles taper downwards in elevation in the direction the gold (and all heavies), precious metals concentrate discharge end of the table. This facilitates the ease with which mineral particles can move transversal to the tables axis or shaker-line, therefore helpingseparation over the complete tablelength. Riffle heights and pattern designs are selected based on the desired and required duty/function expected.
Preparing several size fractions for tabling is usually achieved in a hydrosizer. Ifgold is present in both coarse and finely divided sizings at least three, or perhapsfour separate size fractions must be treated, each under a different set of operatingconditions. Tables operate most efficiently with a closely sized feed. The slurry fansout across a smooth section of the surface until it reaches the riffles. The lighterand very fine particles are washed over the riffles and moved along the riffles by thereciprocating motion imparted to the deck while the heavier particles are held back. The concentrates of heavy mineral and gold are discharged over the end of thedeck. Tailings are washed over the lower edge and a middlings fraction is taken offbetween the lower edge of the concentrate strip and the higher edge of the tailingstrip.
Wash water usage is dependent upon the particle diameter and varies from aslow as 0.7 m/t/h of solids for slime decks, up to 56 m/t/h for coarse solidsseparation. Coarse fractions are usually treated at feed rates of up to 1 t/h using approximately 15 to 20 mm stroke lengths at around 280 rpm (Wilfley table data). Thestroke lengths of finer fractions are reduced to 915 mm with increased speeds ofup to 325 rpm but, because of the corresponding lower film, thickness capacitiesmay fall to around 0.25 t/h. The inclination of the deck is adjusted during operationusing a hand-operated tilting device. It is important following each adjustment toallow the table operation to settle down before making a fresh adjustment. The correct inclination is reached when the ribbon of concentrates is clearly defined andremains steady.
The extreme sensitivity of water depths and corresponding current depths to obtain F = 1, and the use of stationary tables as primary concentrating units, was probably the main reason for the consistently low (R.E. 6065%) gold recoveries of early dredgers. For such table types, the fluid forces are applied to the stream-beds as a whole and ripples form, which keep the sand in orbital motion and provide for the denser particles to sink to the bed. Deposition is most favoured by anti-dune conditions produced by free-surface flow at or near the supercritical state. Such bed forms are in phase with the water surface and are produced in the rapid flow conditions of Froude Number F = 1. In this state of flow, the bed forms of the upper flow regime are stable. Below F = 1 the flow is tranquil and shear forces are reduced. In reviewing recovery distributions of certaindredgers it wasnoted that some coarse gold reported with the tailing after passing through two stages of tabling and that fine gold did not concentrate noticeably down the line.
I consider the gold shaker table to be a shaking sluice box OR self cleaning sluice as they both essentially are classifiers used as heavy gold concentrating devices. Apart from nuggets; generally the valuable minerals like heavy precious metals like platinumandpalladium thatcan berecovered by tables and sluices, are found in one size range (generally the finest) and the waste minerals in another. On agold sluice, large particles (gravel) travel by sliding and rolling over the riffles, with finer particles travelling by saltation. Sand travels by a combination of modes described earlier with some saltation over the riffles.Very fine particles are maintained in suspension by turbulent and inter-particle collision.
Riffles function properly only if in the space between them and the slurry is sufficiently live (turbulent) to reject the lighter particles, but not so lively that the gold cannot settle. On a gold shaker table, those particles are allowed to settle as they will get transported to the other end by the vibrating/shaking back-and-forth motion. Lower grade, light pieces, will be able to escape the table a the riffles becomes shorter along the tables length.Once the particle has started to move, the coefficient of friction changes to a dynamic coefficient of friction. In fact, because the fluid push on the particles is larger at the top of the particle than at the bottom, the particle rolls, largely according to the shape of the particle and according to the speed. At low speeds, the effective friction is the relatively large coefficient of dynamic sliding friction, and at high speeds it is the lower coefficient of rolling friction. The change probably takes place partly continuously and partly discontinuously. As a first approximation, the dynamic coefficient of friction may, however, be regarded as constant.
In a sluice box, the settling of heavy minerals between the riffles requires frequent stirring to prevent the riffle spaces from blinding. This also disturbs the gold, which then moves progressively down-sluice. Frequent clean-ups are needed to avoid excessive loss. Boxes may be used in parallel to avoid loss of production time. One box is kept in operation while cleaning up in the other.
Effect of Deck Roughness: The foregoing analysis is based on the postulate that the deck is perfectly smooth. If the deck is rough, i.e., if it has at its surface some recesses capable of partly shielding fine particles from the rub of the fluid, the slope required to move the particles by either rolling or sliding will be increased. At the same time such an effect, while present also for large particles, may be so much smaller for them as to be imperceptible. The relationship of critical angle to size obtained above will therefore not hold for rough surfaces. The problem is analytically complex and it is nevertheless a problem that might well be explored further if a full insight is desired into the mechanism of flowing-film concentration.
Adjustments are provided in all tables for the amount of wash water, the cross tilt, the speed, and the length of the stroke. The speed of the table ranges usually from 180 to 270 strokes per minute, and the strokes are from 1/2 to 1 1/2 long.
Variations in character of feed require variations in operation. The operators duty is to take care of them by adjusting the tilt, the wash water, and the position of the splitters that control discharge of table into concentrate, middling, and tailing launders. One man may look after 10 to 100 tables, depending upon the regularity of the feed and the difficulty of the task assigned to the table.
A coarse feed can be treated in larger amounts than a fine feed. It would seem that the treatable tonnage increases at least as the square of the average size (theory indicates that it increases as the cube of the particle size).
A roughing operation is preferably conducted on a fully riffled deck. These decks have a greater capacity because the particles are treated throughout the deck in the form of a teetering suspension many particles deep instead of as a restive layer one particle deep. Such decks do not provide flowing-film concentration but some sort of jigging. On the other hand, a cleaning operation is preferably performed on a partly riffled deck.
It is clear that minerals of different specific gravity must be present the greater the spread in specific gravity between minerals, the greater the capacity since that sort of condition permits crowding without considerable penalty.
The effect of locked particles on capacity of tables should also be recognized. These particles behave in a fashion intermediate between that of pure particles of their constituent minerals. It is as if a three-product separation were sought in which one of the products would guide-in specific gravity between the two other.
Table capacity may be as high as 200 tons per 24 hr. on a fully riffled deck 4 by 12 ft. treating minus 3-mm. sulphide ore having a specific gravity of about 3.0 (roughing duty), or 500 tons per 24 hr. But table capacity may be as low as 5 tons per 24 hr., or even less, for fine ore (minus 0.3 mm.) if there is only a small specific-gravity differential between minerals.
Operating a shaking table is cheap as power requirement per table are typically low. Most of the energy is expended to move the deck, which must therefore be as light as is consistent with rigidity. Laboratory gold shaking table testingreport.
There are a few steps that need to be taken in order to get yourgold shaker table to work efficiently. The first step that aspiring gold miners must take would be to make sure that all four corners of the table are level from forward to back. It is very important to anchor the bolts so that the shaking of the gold goes to the table and not through the frame. After you begin running your table, you may need to adjust your table from side to side to maintain an even flow of materials on both sides of the table.
A gold shaker table contains a water access point where you can fill it with clean water, which can be seen right under the control area. Alternatively you can directly fill the tank of the shaker table with clean water. The water access point allows you to connect a clean water system through a garden hose. The valve that is right behind the tank is then turned off and the pump system is not running during the process of running fresh water. When clean washing water is distributed at the top of the table at right angles, particles are moved diagonally across the deck and separate from each other according to their size and density. During the fast shaking process, you will gradually begin to see the separation of materials. For example, when you have dirt and rocks that contain materials like lead, sulfides and gold, because of the varying weights of these different materials, you will see these materials venture off in different directions on the shaker table. The lead and the sulfides will be carried over to the right side of the table while the pure gold will be carried over to the far left side of the table.
There is one term to remember when professional gold miners describe the actions of a gold shaker table. When professional gold miners say that small particles of gold are being carried through the grooves, they are referring to the ripples that you can plainly see on the shaker table. When they say that there is an overflow of materials like Black Pyrrhotite, White Quartz, silver and gold on the grooves, then this is a good thing.
When materials are washed by the clean water they are supposed to drop into 3 hoppers/launders underneath the table. There is a centre launderthat will gather the purest portions of gold while the two outside launders will gather some gold, though not as much.
It is crucial to remember to plug the cable of your shaker table into a GFCI (Ground Fault Circuit Interrupter) outlet. Most shaker tables will not work if they are plugged into any other kind of outlet.
In aPercussion Gold Shaker Table,the work of keeping the pulp in a state of agitation, done by the rakes or brushes in the German and Cornish buddies described above, is affected by sudden blows or bumps imparted sideways or endways to the table. The table is made of wood or sheet metal, the surface being either smooth or riffled.
End-bump tables are hung by chains or in some similar manner, so as to be capable of limited movement, and receive a number of blows delivered on the upper end. These blows are given by cams acting through rods, or else the table is pushed forward against the action of strong springs by cams on a revolving shaft, and then being suddenly released is thrown back violently by the springs against a fixed horizontal beam. The movement of the pulp depends on the inertia of the particles, which are thrown backward up the inclined table by the blow given to the table, the amount of movement varying with their mass, and depending, therefore, both on their size and density. The vibrations produced by the percussion also perform the work of the rakes in destroying the cohesion between the particles, and a stream of water washes them down. The result is that the larger and heavier particles may be made to travel up the table in the direction in which theyare thrown by the blow, by regulating the quantity of water, while the smaller and lighter particles are carried down. These machines yield only two classes of material, headings and tailings. One such machine, the Gilpin County Gilt Edge Concentrator was devised in Colorado, and has displaced the blanket sluices atalmost all the mills at Blackhawk. It consists (Fig. 46) essentially of a cast-iron or copper table, 7 feet long and 3 feet wide, divided into two equal sections by a 4-inch square bumping-beam. The table has raised edges, and its inclination is about 4 inches in 5 feet at its lower end, the remaining 1 feet at the head having a somewhat steeper grade. The table is hung by iron rods to an iron frame, the length of the rods being altered by screw threads, so as to regulate the inclination to the required amount. A shaft with double cams, A, making 65 revolutions per minute, enables 130 blows per minute to be given to the table in the following manner; onbeing released by the cam, the table is forced forward by the strong spring, B, so that its head strikes against the solid beam,C, which is firmly united to the rest of the frame.
The pulp coming from the copper plates is fed on to the table near its upper end by a distributing box, D, and is spread out and kept in agitation by the rapid blows. Thesulphides settle to the bottom of the pulp, and are thrown forward by the shock, and eventually discharged over the head of the table at the left hand of the figure, while the gangue is carried down by the water and discharged at the other end. One machine is enough to concentrate the pulp from five stamps. If the table consists of amalgamated copper plates, it is of some use for catching free gold also, treating about 8 cwts. of ore per hour. This machine is not so effective in saving slimed pyrites as the Wilfley table or the vanners.
Gold shaker tables are environmentally friendly (chemical free) for recovering pure gold as they can play an important part in reducing the use of mercury by gold miners. With gold shaker tables miners dont need to resort to mercury amalgamation or cyanide to recover gold. The filter will constantly need to be removed and cleaned as it will get dirty even after using the table a few times.
Miners can design and construct a basic shaking table out of cheap materials that are affordable in local stores, including a drive mechanism that contains bicycle gears, chains and rubber bands that are made from car tire inner tubes. The drive mechanism for a gold shaker table can be a hand crank or it can contain parts of a motorcycle frame and engine. If one prefers to use a motor for his or her table, either an electric motor or a motor that runs on diesel fuel would be the ideal options.
It is important to keep in mind that there is no one specific way to create your own gold shaker table system. Many professional gold mining organizations will create tables of different shapes and sizes to cater to the needs of their customers. Some shaker table systems will feature machines that can crush hard rocks, which are referred to as jaw crushers. The speeds of shaker table systems will vary as they can shake from hundreds to thousands of pounds of materials per hour.
Our automatic production line for the grinding cylpebs is the unique. With stable quality, high production efficiency, high hardness, wear-resistant, the volumetric hardness of the grinding cylpebs is between 60-63HRC,the breakage is less than 0.5%. The organization of the grinding cylpebs is compact, the hardness is constant from the inner to the surface. Now has extensively used in the cement industry, the wear rate is about 30g-60g per Ton cement.
Grinding Cylpebs are made from low-alloy chilled cast iron. The molten metal leaves the furnace at approximately 1500 C and is transferred to a continuous casting machine where the selected size Cylpebs are created; by changing the moulds the full range of cylindrical media can be manufactured via one simple process. The Cylpebs are demoulded while still red hot and placed in a cooling section for several hours to relieve internal stress. Solidification takes place in seconds and is formed from the external surface inward to the centre of the media. It has been claimed that this manufacturing process contributes to the cost effectiveness of the media, by being more efficient and requiring less energy than the conventional forging method.
Because of their cylindrical geometry, Cylpebs have greater surface area and higher bulk density compared with balls of similar mass and size. Cylpebs of equal diameter and length have 14.5% greater surface area than balls of the same mass, and 9% higher bulk density than steel balls, or 12% higher than cast balls. As a result, for a given charge volume, about 25% more grinding media surface area is available for size reduction when charged with Cylpebs, but the mill would also draw more power.
Product Introduction JXSC jaw type rock crusher is usually used as a primary crusher and secondary crusher to reduce the size of medium-hard materials to smaller physical size. Jaw rock crushers are capable of working with the mobile crushing station, underground crushing because of its related small volume. Capacity: 1-1120TPH Max Feeding Size: 120-1200mm Application Mining, metallurgy, building materials, quarrying, gravel & sand making, aggregate processing, recycling, road and railway construction and chemical industry, etc. Suitable Material Granite, marble,basalt, limestone, coal, quartz, pebble, iron ore, copper ore, etc.
40 years of manufacturing and engineering experience keep us innovative and knowledge in the rock break machines and its applications, which thus provide reliable industry rocks crushers and solutions for every customer using jaw crusher manufacturers JXSC machines to meet their production goals. The jaw crusher machine family consists of different sized models that are designed to bring maximum output with minimum cost. Some workplaces have limited conditions and are unable to provide electricity or are underpowered. According to these conditions, JXSC specially designed diesel jaw crusher. The diesel-jaw crusher is actually with electric, but the original jaw crusher was added with a diesel engine equipment that a dual-purpose crusher.
JXSC the crushers machine with a non-welded frame has been proved that it has outstanding solid and durable strength. All the alloy casting frame components turn out that with premium quality, wear-resistant property.
The design of pitman and long stoke improves productivity and reduction. A wider feeding material opening increases the volume of insulating material and makes the ore material entering the crushers crushing chamber smoothly. A sharp angle makes the materials flow down speed faster and reduces the wear cost. Besides, the strike force could be stronger thus increase the production efficiency as well as the reduction ratio.
Types of jaw crushers: on the basis of the stone break equipment size and capacity can divide into a heavy and small(mini) portable jaw rock crushers. According to the working principle can be split into single toggle and double toggle jaw rock crushers machine.
A series of jaw stone crushers use compressive and squeezing force for reducing materials. This physical force is created by the two jaw plates, one of which is a movable plate and another is fixed, both of them are made of manganese. A V-shaped cavity, crushing chamber, is formed and the hydraulic discharge gap width of the crushing chamber, we can determine the suited feeding material size and discharging size, the width of top feeding is larger than that of bottom discharging.
Jaw crusher is a heavy-duty machine that crushes hard materials. So its hence muse be robustly constructed. Crusher frame is made from steel or cast iron. The jaws are made of cast steel. The liners are made fromNi-hard, Ni-Cr alloyed cast iron or manganese steel which can replaceable and use to reduce frame wear. The cheek plates are also made from hard alloy steel and installed to the sides of the crushing chamber to protect the frame from wear.
The jaws can be made in smooth or corrugated, but often corrugated. Because the latter crushing the hard and abrasive ores is better. The angle between the jaws is usually less than 26. This is because a large angle will cause the particle to slip which non-crush.
It uses curved plates to avoid the near the discharge of jaw crusher blocking. The bottom of the swinging jaw is concave, and the relative lower part of the fixed jaw is convex. The materials reduction in size when nears the exit. So the material is distributed over a larger area, and the jaws plates wear less.
The type of crushed materials determines how to design the max amplitude of swing of the jaw and the amplitude adjusted by changing the eccentric. The length from 1 to 7 cm depends on the crusher machine size. Jaw crushers are supplied in sizes up to 1,600 mm (gape)1,900 mm (width). For coarse crushing application (closed set~300 mm), capacities range up to 1200 tph.
Jaw crusher parts must have some wear after a period of use, but the easily damaged parts will wear out more. The price of crushing equipment with the same specifications and handling capacity is different in the material of parts.
Guard Plate The guard plate is made of high-quality high manganese steel, which is located between the fixed plate and the movable plate. The whole body is mainly to protect the jaw crusher frame wall.
Toothed Plate Tooth plate is divided into movable and fixed tooth plate, but both is made from high manganese steel casting. In order to prolong its service life, its shape is designed to be symmetrical. That is when one end of the wear can be used to turn the head. The movable and the fixed teeth plate are the main parts for stone crushing. So the movable teeth plate is installed on the movable jaw to protect the movable jaw.
Toggle Plate The toggle plate is a cast iron piece that has been precisely calculated. It is not only a force transmission component but also the safety parts of the crusher. When the crusher falls into the non-crushing material and makes the machine beyond the normal load, the toggle plate will immediately break. Then the crusher machine stops operation, thus avoiding the damage of the whole machine. The toggle plate and the toggle plate spacer adopt the rolling contact model which less attrition under normal use. It just needs smear a layer of grease on the contact surface is ok.
Triangular Belt When the motor transmits power, the triangle belt is connected with the pulley and the grooved pulley of the motor to drive the eccentric shaft and make the moving jaw move back and forth according to the predetermined track.
The tooth plate of the most jaw crushers are made of manganese steel, bearing linings are made of babbitt alloy, sliding blocks are made of carbon steel, toggle plates are made of cast iron, springs are made of 60SiMn. Regular Inspection and maintenance of the machine can extend its service life. In order to reduce customer costs, we will generally be in the purchase of customers are advised to buy some spare parts. Because once the parts need to be replaced, the temporary purchase will take some time. The wait time may cause the entire breakage line to suspend operations, thereby increasing operating costs.
In short, the jaw stone crushers are mainly used for primary crusher, the crushing stone is relatively large. The types of crusher machine's chamber are deep and no dead zone. It improves that the feeding capacity and output. The crushing ratio is large and the product particle size is even. Shim type outlet adjustment device, reliable and convenient, large hydraulic adjustment range that increased the flexibility of the equipment. Simple structure, reliable work and low operation cost. The adjustment range of hydraulic discharge opening is large, which can meet the requirements of different users, low noise and less dust.
Impact crusher for crushing medium-hard stones, and mostly used for secondary crusher. The impact crushers have a big feeding port, high crushing cavity, high material hardness, big block size and little stone powder. Convenient maintenance, economic and reliable, high comprehensive benefit.
Jiangxi Shicheng stone crusher manufacturer is a new and high-tech factory specialized in R&D and manufacturing crushing lines, beneficial equipment,sand-making machinery and grinding plants. Read More
January 25, 2019, the Vale iron mine in Brazil experienced a dam break, which led to the closure of large-scale mines. At the same time, the two major mines in Australia, BHP and Rio Tinto, were affected by the hurricane to reduce their shipments.
Since the end of January this year, iron ore prices have risen sharply, far exceeding the increase in steel and other raw materials. Therefore, iron ore has become the most popular investment in the eyes of investors. In July 2019, the price of iron ore reached more than US$120 per ton.
For the time being, the investment prospect of iron ore is very bright. So what is the global reserves and distribution of iron ore? How much does it cost to build an iron ore processing line? This article will answer you in detail.
The data released by USGS in early 2005 showed that the global iron ore reserves were 160 billion tons, the reserves of mineral iron (ie, iron contained in iron ore) were 80 billion tons and the basic reserves were 180 billion tons.
The worlds iron ore is mainly reserved in Ukraine, Russia, Brazil, China and Australia. The reserves are 30 billion tons, 25 billion tons, 21 billion tons, 21 billion tons and 18 billion tons respectively, accounting for 18.8%, 15.6%, 13.1%, 13.1% and 11.3% of the worlds total reserves respectively.
In addition, Kazakhstan, the United States, India, Venezuela and Sweden also have rich iron ore resources, and their iron ore reserves are 8.3 billion tons, 6.9 billion tons, 6.6 billion tons, 4 billion tons and 3.5 billion tons, respectively accounting for 5.2%, 4.3%, 4.1%, 2.5% and 2.2% of the worlds total iron ore reserves.
The worlds mineral iron is mainly reserved in Brazil, Russia and Australia, with reserves of 14 billion tons, 14 billion tons and 11 billion tons respectively, accounting for 17.5%, 17.5% and 13.8% of the worlds total reserves. The sum of the reserves in the three countries accounts for 48.8% of the total reserves in the world.
Mineral iron reserves and basic reserves are the most representative of the richness of a countrys iron ore resources, so Brazil, Russia and Australia are the worlds richest iron ore resources. At the same time, it shows that although Ukraine and China have large reserves of iron ore, they have more lean ore and less rich ore.
Iron ore resources are mainly reserved in more than10 countries, and 90% of proven reserves are distributed in10 countries and regions. They are: CIS (proven reserves of 114 billion tons, of which Russia is more than 80 billion tons), Brazil (68 billion tons), China (50 billion tons), Canada (over 36 billion tons), Australia (35 billion tons) ), India (17.57 billion tons), the United States (17.4 billion tons), France (7 billion tons), Sweden (3.65 billion tons).
The global iron mine reserves increased from 232 billion tons in 1996 to 370 billion tons in 2006, an increase of 59.5% in 10 years. The total amount of iron ore resources in the world is estimated to exceed 800 billion tons (the amount of iron ore), and the iron content exceeds 230 billion tons and there is still great potential for future discovery.
The major countries of iron ore resources include Brazil, Australia, China, Russia, Kazakhstan, Ukraine, the United States, India, Sweden, and Venezuela. High-grade ore is widely distributed in Brazil, Australia, India and other countries. The low mining cost and relatively high grade of iron ore make these countries the major iron ore suppliers in the world.
Before dry selection, the lean iron ore requires millimeter-scale fine crushing by the fine crusher. If the particle size of the iron ore is not small enough in the crushing stage, low-grade iron ore is difficult to be selected later, which will cause serious waste of resources.
The common problem in the iron ore crushing production line is that the wear parts of the fine crusher are seriously worn out, and the repair and maintenance of the fine crusher are too frequent, which makes the production efficiency of the iron ore crushing production line lower.
Different iron ore has different features. According to these features, the crushers are made of different materials. Therefore, the prices of iron ore crusher are different. However, reasonable crushing processes and crusher can be used to save the cost investment and achieve the required crushing effect.
In the crushing process of lean iron ore, in order to obtain the best process configuration and the lowest crushing cost, it is necessary to master the relationship of particle size among the primary crushing, the secondary crushing and the fine crushing.
For medium and low hardness lean iron ore, the second crushing equipment can use the impact crusher. The iron ore impact crusher utilizes a plate hammer on a high-speed moving rotor to produce a high-speed impact on the iron ore fed into the crushing chamber. The crushed iron ore is thrown at a high speed in the tangential direction toward the counter-attack at the other end of the crushing chamber.
During this process, the iron ore will collide with each other, causing cracks and looseness. When the iron ore particle size is smaller than the gap between the counterattack plate and the plate hammer, it is discharged outside the machine.
For high-hardness iron ore, a cone crusher can be used for the secondary crushing equipment. The HXJQ short-headed cone crusher can achieve a fine crushing effect of 3 to 13mm, which can fully meet the requirements of dry selection and grinding. However, due to the high hardness of such iron ore, the impact on the wear parts is large, so ordinary crushing equipment is difficult to exert its advantage.
In areas with low power consumption, the sand making machine developed and produced by HXJQ can achieve the fine crushing effect of high hardness and high output iron ore. Not only can the iron ore particle size be reduced to improve the dry selection efficiency, but also the ball mill load and operating cost can be greatly reduced, and the ball mill production capacity can be improved.
The price of iron ore crushing production line is related to various factors such as equipment combination, output level, and quality. Of course, the quotation standards of different manufacturers will also be different. Customers also need to analyze specifically when purchasing.
The comparison found that the price of the iron ore crushing production line of HXJQ Machinery is the most economical and reasonable, ensuring that the production line has a long service life, less failure, high efficiency, good effect, energy-saving and environmental protection, and can keep its price lower than other manufacturers 6% to 7%.
At the same time, the HXJQ configuration plan is all-sided, and there is a wide variety of equipment in HXJQ Machinery. If you are interested in these crushing equipment, please submit your relevant information on the right side, we will arrange a professional engineer to answer your questions.
Roll crushers are generally not used as primary crushers for hard ores. Even for softer ores, like chalcocite and chalcopyrite they have been used as secondary crushers. Choke feeding is not advisable as it tends to produce particles of irregular size. Both open and closed circuit crushing are employed. For close circuit the product is screened with a mesh size much less than the set.
Fig. 6.4 is a typical set up where ore crushed in primary and secondary crushers are further reduced in size by a rough roll crusher in open circuit followed by finer size reduction in a closed circuit by roll crusher. Such circuits are chosen as the feed size to standard roll crushers normally do not exceed 50mm.
Cone crushers were originally designed and developed by Symons around 1920 and therefore are often described as Symons cone crushers. As the mechanism of crushing in these crushers are similar to gyratory crushers their designs are similar, but in this case the spindle is supported at the bottom of the gyrating cone instead of being suspended as in larger gyratory crushers. Fig. 5.3 is a schematic diagram of a cone crusher. The breaking head gyrates inside an inverted truncated cone. These crushers are designed so that the head to depth ratio is larger than the standard gyratory crusher and the cone angles are much flatter and the slope of the mantle and the concaves are parallel to each other. The flatter cone angles helps to retain the particles longer between the crushing surfaces and therefore produce much finer particles. To prevent damage to the crushing surfaces, the concave or shell of the crushers are held in place by strong springs or hydraulics which yield to permit uncrushable tramp material to pass through.
The secondary crushers are designated as Standard cone crushers having stepped liners and tertiary Short Head cone crushers, which have smoother crushing faces and steeper cone angles of the breaking head. The approximate distance of the annular space at the discharge end designates the size of the cone crushers. A brief summary of the design characteristics is given in Table 5.4 for crusher operation in open circuit and closed circuit situations.
The Standard cone crushers are for normal use. The Short Head cone crushers are designed for tertiary or quaternary crushing where finer product is required. These crushers are invariably operated in closed circuit. The final product sizes are fine, medium or coarse depending on the closed set spacing, the configuration of the crushing chamber and classifier performance, which is always installed in parallel.
For finer product sizes, i.e. less than 6mm, special cone crushers known as Gyradisc crushers are available. The operation is similar to the standard cone crushers except that the size reduction is caused more by attrition than by impact, . The reduction ratio is around 8:1 and as the product size is relatively small the feed size is limited to less than 50mm with a nip angle between 25 and 30. The Gyradisc crushers have head diameters from around 900-2100mm. These crushers are always operated in choke feed conditions. The feed size is less than 50mm and therefore the product size is usually less than 6-9mm.
Crushing is accomplished by compression of the ore against a rigid surface or by impact against a surface in a rigidly constrained motion path. Crushing is usually a dry process and carried out on ROM ore in succession of two or three stages, namely, by (1) primary, (2) secondary, and (3) tertiary crushers.
Primary crushers are heavy-duty rugged machines used to crush ROM ore of () 1.5m size. These large-sized ores are reduced at the primary crushing stage for an output product dimension of 1020cm. The common primary crushers are of jaw and gyratory types.
The jaw crusher reduces the size of large rocks by dropping them into a V-shaped mouth at the top of the crusher chamber. This is created between one fixed rigid jaw and a pivoting swing jaw set at acute angles to each other. Compression is created by forcing the rock against the stationary plate in the crushing chamber as shown in Fig.13.9. The opening at the bottom of the jaw plates is adjustable to the desired aperture for product size. The rocks remain in between the jaws until they are small enough to be set free through this opening for further size reduction by feeding to the secondary crusher.
The type of jaw crusher depends on input feed and output product size, rock/ore strength, volume of operation, cost, and other related parameters. Heavy-duty primary jaw crushers are installed underground for uniform size reduction before transferring the ore to the main centralized hoisting system. Medium-duty jaw crushers are useful in underground mines with low production (Fig.13.10) and in process plants. Small-sized jaw crushers (refer to Fig.7.32) are installed in laboratories for the preparation of representative samples for chemical analysis.
The gyratory crusher consists of a long, conical, hard steel crushing element suspended from the top. It rotates and sweeps out in a conical path within the round, hard, fixed crushing chamber (Fig.13.11). The maximum crushing action is created by closing the gap between the hard crushing surface attached to the spindle and the concave fixed liners mounted on the main frame of the crusher. The gap opens and closes by an eccentric drive on the bottom of the spindle that causes the central vertical spindle to gyrate.
The secondary crusher is mainly used to reclaim the primary crusher product. The crushed material, which is around 15cm in diameter obtained from the ore storage, is disposed as the final crusher product. The size is usually between 0.5 and 2cm in diameter so that it is suitable for grinding. Secondary crushers are comparatively lighter in weight and smaller in size. They generally operate with dry clean feed devoid of harmful elements like metal splinters, wood, clay, etc. separated during primary crushing. The common secondary crushers are cone, roll, and impact types.
The cone crusher (Fig.13.12) is very similar to the gyratory type, except that it has a much shorter spindle with a larger-diameter crushing surface relative to its vertical dimension. The spindle is not suspended as in the gyratory crusher. The eccentric motion of the inner crushing cone is similar to that of the gyratory crusher.
The roll crusher consists of a pair of horizontal cylindrical manganese steel spring rolls (Fig.13.14), which rotate in opposite directions. The falling feed material is squeezed and crushed between the rollers. The final product passes through the discharge point. This type of crusher is used in secondary or tertiary crushing applications. Advanced roll crushers are designed with one rotating cylinder that rotates toward a fix plate or rollers with differing diameters and speeds. It improves the liberation of minerals in the crushed product. Roll crushers are very often used in limestone, coal, phosphate, chalk, and other friable soft ores.
The impact crusher (Fig.13.15) employs high-speed impact or sharp blows to the free-falling feed rather than compression or abrasion. It utilizes hinged or fixed heavy metal hammers (hammer mill) or bars attached to the edges of horizontal rotating discs. The hammers, bars, and discs are made of manganese steel or cast iron containing chromium carbide. The hammers repeatedly strike the material to be crushed against a rugged solid surface of the crushing chamber breaking the particles to uniform size. The final fine products drop down through the discharge grate, while the oversized particles are swept around for another crushing cycle until they are fine enough to fall through the discharge gate. Impact crushers are widely used in stone quarrying industry for making chips as road and building material. These crushers are normally employed for secondary or tertiary crushing.
If size reduction is not completed after secondary crushing because of extra-hard ore or in special cases where it is important to minimize the production of fines, tertiary recrushing is recommended using secondary crushers in a close circuit. The screen overflow of the secondary crusher is collected in a bin (Fig.13.16) and transferred to the tertiary crusher through a conveyer belt in close circuit.
Primary jaw crushers typically operate in open circuit under dry conditions. Depending on the size reduction required, the primary jaw crushers are followed by secondary and tertiary crushing. The last crusher in the line of operation operates in closed circuit. That is, the crushed product is screened and the oversize returned to the crusher for further size reduction while the undersize is accepted as the product. Flow sheets showing two such set-ups are shown in Figs. 3.1 and 3.2.
Jaw crushers are installed underground in mines as well as on the surface. When used underground, jaw crushers are commonly used in open circuit. This is followed by further size reduction in crushers located on the surface.
When the run of mine product is conveyed directly from the mine to the crusher, the feed to the primary crusher passes under a magnet to remove tramp steel collected during the mining operation. A grizzly screen is placed between the magnet and the receiving hopper of the crusher to scalp (remove) boulders larger than the size of the gape. Some mines deliver product direct to storage bins or stockpiles, which then feed the crushers mechanically by apron feeders, Ross feeders or similar devices to regulate the feed rate to the crusher. Alternately haulage trucks, front-end loaders, bottom discharge railroad cars or tipping wagons are used. In such cases, the feed rate to the crusher is intermittent which is a situation generally avoided. In such cases of intermittent feed, storage areas are installed and the feed rate regulated by bulldozers, front loaders or bin or stockpile hoppers and feeders. It is necessary that the feed to jaw crushers be carefully designed to balance with the throughput rate of the crusher. When the feed rate is regulated to keep the receiving hopper of the crusher full at all times so that the volume rate of rock entering any point in the crusher is greater than the rate of rock leaving, it is referred to as choke feeding. During choke feeding the crushing action takes place between the jaw plates and particles as well as by inter-particle compression. Choke feeding necessarily produces more fines and requires careful feed control. For mineral liberation, choked feeding is desirable.
When installed above ground, the object of the crushing circuit is to crush the ore to achieve the required size for down stream use. In some industries, for example, iron ore or coal, where a specific product size is required (iron ore 30+6mm), careful choice of jaw settings and screen sizes are required to produce the minimum amount of fines (i.e. 6mm) and maximum the amount of lump ore within the specified size range. For hard mineral bearing rocks like gold or nickel ores where liberation of minerals from the host rock is the main objective, further stages of size reduction are required.
A gold ore was crushed in a secondary crusher and screened dry on an 1180micron square aperture screen. The screen was constructed with 0.12mm diameter uniform stainless steel wire. The size analysis of the feed, oversize and undersize streams are given in the following table. The gold content in the feed, undersize and oversize streams were; 5ppm, 1.5ppm and 7ppm respectively. Calculate:
The self tuning control algorithm has been developed and applied on crusher circuits and flotation circuits [22-24] where PID controllers seem to be less effective due to immeasurable change in parameters like the hardness of the ore and wear in crusher linings. STC is applicable to non-linear time varying systems. It however permits the inclusion of feed forward compensation when a disturbance can be measured at different times. The STC control system is therefore attractive. The basis of the system is:
The disadvantage of the set up is that it is not very stable and therefore in the control model a balance has to be selected between stability and performance. A control law is adopted. It includes a cost function CF, and penalty on control action. The control law has been defined as:
A block diagram showing the self tuning set-up is illustrated in Fig. 18.27. The disadvantage of STC controllers is that they are less stable and therefore in its application a balance has to be derived between stability and performance.
Bone recycling is a simple process where useful products can be extracted. Minerals such as calcium powder for animal; feed are extracted from the bone itself. The base material for cosmetics and some detergent manufacturing needs are extracted from the bone marrow.
The bone recycling process passes through seven stages starting from crushing and ending with packing. Figure 13.14 gives a schematic diagram showing the bone recycling process which goes through the following steps:
Following the standard procedures in the Beijing SHRIMP Center, zircons were separated using a jaw crusher, disc mill, panning, and a magnetic separator, followed by handpicking using a binocular microscope. The grains were mounted together with the standard zircon TEM (417Ma, Black etal., 2003) and then polished to expose the internal structure of the zircons. Cathodoluminescence (CL) imaging was conducted using a Hitachi SEM S-3000N equipped with a Gatan Chroma CL detector in the Beijing SHRIMP Center. The zircon analysis was performed using the SHRIMP II also in the Beijing SHRIMP Centre. The analytical procedures and conditions were similar to those described by Williams (1998). Analytical spots with 25m diameter were bombarded by a 3nA, 10kV O2 primary ion beam to sputter secondary ions. Five scans were performed on every analysis, and the mass resolution was 5000 (at 1%). M257 standard zircon (561.3Ma, U=840ppm) was used as the reference value for the U concentration, and TEM standard zircons were used for Pb/U ratio correction (Black etal., 2003). Common Pb was corrected using the measured 204Pb. Data processing was performed using the SQUID/Isoplot programs (Ludwig, 2001a,b). Errors for individual analyses are at 1, but the errors for weighted average ages are at 2.
A stockpile can be used to blend ore from different sources. This is useful for flotation circuits where fluctuations ingrade can change the mass balance and circulating loads around the plant. Blending can also be done on the ROMpad.
The lowest cost alternative is to have no surge at all, but rather to have a crushing plant on line. This is workable for small-scale plant with single-stage jaw crushers as the availability of these simple plant is very high provided control over ROM size is maintained.
The second alternative is to use a small live surge bin after the primary crusher with a secondary reclaim feeder. Crushed ore feeds this bin continuously and the bin overflows to a small conveyor feeding a dead stockpile. In the event of a primary crusher failure, the crusher loader is used to reclaim the stockpile via the surge bin, which doubles as an emergency hopper.
For coarse ore, the next alternative is a coarse ore stockpile. Stockpiles of this type are generally 1525% live and require a tunnel (concrete or Armco) and a number of reclaim feeders to feed the milling circuit.
Multi-stage crushing circuits usually require surge capacity as the availability of each unit process is cumulative. A fine-ore bin is usually required. Smaller bins are usually fabricated from steel as this is cheaper. Live capacity of bins is higher than stockpiles but they also require a reclaim tunnel and feeders.
A wide variety of jaw crusher for iron ore options are available to you. You can also submit buying request for the abs sensor and specify your requirement on okchem.com, and we will help you find the quality jaw crusher for iron ore suppliers.
There are a lot off suppliers providing jaw crusher for iron ore on okchem.com, mainly located in Asia. The jaw crusher for iron ore products are most popular in India, Pakistan, Vietnam, Indonesia, Brazil, Russia, Mexico, United States, Turkey, Germany, etc.
The mineral and mining industry is obsessed with sizing which is actually the most essential part of almost every process in the sector. Be it coal, salt, ore, rock, wood chips or anything like clay, the industrial processing of the same involves crushing the core step for best processing. Mineral and mining industries use ore crushers to break down the material to evenly sized small granules or cubes as per the requirement. Ecoman, the most trusted partner for those firms working across the mining and mineral industries, has been serving the sector with exclusive range of iron ore crushers that are carefully designed and manufactured to best suit the common requirements of the mining industry processes. Having been the most eminent iron ore suppliers in the country, we at Ecoman manufacture high quality iron ore crusher machines that are well equipped to size industrial raw materials into desired sizes. With a spectrum of exclusive crafted crusher machines that deliver splendid crushing, beneficiation, size reduction, mixing & grinding, lump breaking, Ecomans clients applause us for our extensively reliable, truly versatile, and apt for unique applications. Ecomans machines were installed in a spectrum of mineral industries:
Possessing exclusive expertise, exuberant processing techniques and effective implementation strategies, Ecoman offers profound crushers that are best suitable for applications across various industrial applications. To get an instant quote for your unique requirement, write to us at [email protected]
This is to certify that ECOMAN's Jaw Crusher of size 36" x 24" is working satisfactorily, at our site at Bhuj, for last three years. It is giving rated outputs without any failures. Their service is efficient & prompt.
Iron ore mining methods vary by the kind of ore being mined. You can find four major forms of iron ore deposits worked currently, with respect to the mineralogy and geology of the ore deposits. These are magnetite, titanomagnetite, massive hematite and pisolitic ironstone deposits.
Iron ore refers back to the ore containing iron or iron compound, which is one of the most important garbage in output of steel. There are many large-scale iron ore area which have high value of exploitation australia wide, Brazil, India, SA, Canada, Ukraine, Liberia as well as other countries. Main iron ores are magnetite,limonite, hematite ore, iron silicate ore, iron silicate mineral, etc. Probably the most widely used crushers in iron ore mining business are jaw iron ore crusher, cone crusher, hammer iron ore crusher and high-efficient iron ore fine crushers, etc. In iron ore mining, consumers usually choose a complete iron ore crushing production line for better efficiency. Currently, typically the most popular iron ore production line consists of two jaw crushers. After iron ore crushing, the fabric is going to be sent for the magnetic separation, and then in to the ball mill for grinding.
The worlds iron ore resources are concentration australia wide, Brazil, Ukraine, Russia, Kazakhstan, India, the usa, Nigeria, Canada as well as other countries. Nearly all iron ore experiences iron ore processing and it is utilized to make steel. Iron ore processing can be a procedure that contains explosions, shoveling, moving, crushing, grinding, pelletizing etc. Iron ore processing provides a range of coarse sizing that may produce material in 24-inch to .0017-inch particle sizes.
In iron ore crushing and screening process is really a basic connect to concentrator will have an effect on producing indicators. Methods accustomed to include jaw crushing, impact crushing, roll crushing, and pulverizing. To make iron ore size as fine as you can before entering into ball mill, iron ore processors usually are use cone crushers in pre-grinding stage, cone crusher come with an excellent fine crushing power to minish iron ore size. In coarse crushing, 2.1m or 2.2m gyratory crusher is usually being selected, in medium crushing process, processer usually use regular cone crusher, plus fine crushing, short-head kind cone crusher would work.
The size requirement of the primary rock crusher is a function of grizzly openings, ore chute configuration, required throughput, ore moisture, and other factors. Usually, primary crushers are sized by the ability to accept the largest expected ore fragment. Jaw crushers are usually preferred as primary crushers in small installations due to the inherent mechanical simplicity and ease of operation of these machines. Additionally, jaw crushers wearing parts are relatively uncomplicated castings and tend to cost less per unit weight of metal than more complicated gyratory crusher castings. The primary crusher must be designed so that adequate surge capacity is present beneath the crusher. An ore stockpile after primary crushing is desirable but is not always possible to include in a compact design.
Many times the single heaviest equipment item in the entire plant is the primary crusher mainframe. The ability to transport the crusher main frame sometimes limits crusher size, particularly in remote locations having limited accessibility.
In a smaller installation, the crushing plant should be designed with the minimum number of required equipment items. Usually, a crushing plant that can process 1000s of metric tons per operating day will consist of a single primary crusher, a single screen, a single secondary cone crusher, and associated conveyor belts. The discharge from both primary and secondary crushers is directed to the screen. Screen oversize serves as feed to the secondary crusher while screen undersize is the finished product. For throughputs of 500 to 1,000 metric tons per operating day (usually 2 shifts), a closed circuit tertiary cone crusher is usually added to the crushing circuit outlined above. This approach, with the addition of a duplicate screen associated with the tertiary cone crusher, has proven to be effective even on ores having relatively high moisture contents. Provided screen decks are correctly selected, the moist fine material in the incoming ore tends to be removed in the screening stages and therefore does not enter into subsequent crushing units.
All crusher cavities and major ore transfer points should be equipped with a jib-type crane or hydraulic rock tongs to facilitate the removal of chokes. In addition, secondary crushers must be protected from tramp iron by suspended magnets or magnetic head pulleys. The location of these magnets should be such that recycling of magnetic material back into the system is not possible.
Crushing plants for the tonnages indicated may be considered to be standardized. It is not prudent to spend money researching crusher abrasion indices or determining operating kilowatt consumptions for the required particle size reduction in a proposed small crushing plant. Crushing installations usually are operated to produce the required mill tonnage at a specified size distribution under conditions of varying ore hardness by the variation of the number of operating hours per day. It is normal practice to generously size a small crushing plant so that the daily design crushing tonnage can be produced in one, or at most two, operating shifts per working day.
Iron ore is the main direction of iron. The quality of pure iron can be directly fed into the iron smelting furnace, and is related to the ore. The iron ore has a higher impurity content, and you need to process it before it can be put into production.
Iron ore beneficiation can be divided into three stages: crushing, grinding, and beneficiation. Reliable processing equipment can effectively reduce processing costs and improve economic benefits. Jaw crusher is a new type of iron ore crushing equipment. It is specially designed for the developed iron ore. It is stable in operation and has been widely used.
When working, iron ore enters the machine from the feed port, and the motor drives the big wheel throwing and eccentric shaft. The eccentric shaft is connected with the movable jaw. The claw will follow the eccentric shaft around a fixed jaw fixed on the crusher to make irregular movement and movement. The jaw and the fixed jaw are sometimes close, sometimes far. Close, squeeze and shear the iron ore, and generate a moving speed toward the discharge outlet; away from the iron ore, a vacant state, and under the action of gravity, the discharge, qualified materials, and unqualified materials are returned to the cavity and continue to break .
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.
Jaw crusher is a compression style rock crusher, useful in crushing the medium-hard to very hard material into a smaller particle size at primary crushing stage in the crushing circuit.Applicationsmining, quarry, construction waste recycling, aggregate making, etc.MaterialsLimestone, cobblestone, cobblestone, quartz, basalt, iron ore, granite, shale, sandstone, gypsum, and a variety of ores.
Eastman provides you with complete rock crushers and full list of components, original jaw crusher parts, form and function are a perfect fit.If your equipment breaks down, the productivity of the whole factory will be threatened. Critical wear parts are shipped with the goods to ensure they are available when you need them and to reduce maintenance time.Wear parts:Get in Touch with Mechanic