small crushing plant operating guide

small crushing plant operating guide

This EXAMPLE SmallCrushing Plant is designed to crush 500 tonnes per day, operating 12 hours per day with an availability of 70%. The Plant will crush run-of-mine material (-16) to 100%, passing 5/8 at a rate of 60 tonnes per hour. Start-stop stations are provided for all equipment in this Plant at the crusher control panel, to facilitate remote control. A jog/stop station is provided locally for maintenance and checking as well as equipment shutdown.This guideis intended to be read in conjunction with the Flowsheet, Piping and Instrument Diagram.

Run-of-mine ore is delivered to the Crushing Plant via mine rail cars or underground mine haulage trucks, and is dumped through a 16xl6 grizzly into a 350 tonnes coarse ore bin. Oversize material on the coarse ore bin grizzly must be manually removed and broken. The broken material can then be fed into the coarse ore bin. The underside of the coarse ore bin opens onto a 42 variable speed apron feeder, on which there must be a continuous pile of ore to prevent fresh ore from falling directly onto the apron feeder. A nuclear level switch is mounted at the coarse ore bin discharge chute to alarm at the crusher control panel and shutdown the apron feeder should the level drop below a predetermined point. The speed of this feeder is controlled by a hand dial located on the door of this drive in the MCC. Once a speed has been set, and conforms to the feed rate of subsequent equipment and incoming material, the speed can be left constant.

Ore from the apron feeder flows over a 3 stationary grizzly, the +3 ore being fed to a 100 HP 24x36 jaw crusher, and the -3 allowed to flow directly to a 24 conveyor. An interlock is provided whereby the apron feeder will stop if the jaw crusher stops, or if the first conveyor stops. This first conveyor (#1) also has other interlocks, as will be described in the following paragraph.

Secondary crushed material from a 150 HP 4 standard cone crusher is also discharged onto conveyor #1. An electronic soft start unit in the crusher MCC section for this drive ramps the voltage to the motor on a start. A warning horn will sound when the conveyor #1 start buttonpushed and the conveyor will start 30 seconds later. A speed switch is located at the tail pulley of conveyor #1. Six pullcord switches, two located at each pulley and two in the centre of the conveyor, immediately shut the drive down should one be pulled in emergency. A plugged chute detector (tilt switch) will stop the motor should the material build up at the discharge. A tramp iron magnet,suspended above the discharge of conveyor #1, is designed to pick up drill steel and other tramp iron, in order to prevent this material from entering the cone crusher. The magnet is locally controlled only, but will alarm at the crusher control panel should its power fail. The magnet is to be swung away from the conveyor prior to shutting it off to prevent the tramp metal from falling back onto the conveyor.

Conveyor #1 discharges onto a second 24 conveyor (#2), which has the speed, plugged chute, and pullcord switches as described for conveyor #1, except that this conveyor has only 4 pullcord switches. In addition to these switches, a metal detector is positioned above the belt to stop the motor and alarm at the crusher control panel upon metal detection. The size of metal pieces to initiate the alarm is adjustable on the detector.

Conveyor #2 discharges onto a 6 X 10 double deck vibrating screen. Oversize material from both screen decks is fed to the cone crusher and recycled back to conveyor #1. Undersize material from the bottom screen, -5/8, is discharged onto a 3rd conveyor, the 24 #3, and conveyed to the 500 tonne live capacity fine ore bin. If either conveyor #3 or the cone crusher shut down, the screen will stop. On shutdown of the screen; subsequent interlocks shut down the plant.

The cone crusher is equipped with its own lubrication system, including two lube pumps one of which must be running prior to the cone crusher drive start. The cone crusher drive will stop if the both lube pumps are stopped. A low pressure switch in the oil feed line will stop the lube pumps on a low oil pressure condition and hence stop the cone crusher after a 1 minute delay. An oil temperature switch and alarm in the oil return line will alarm on a excessively high oil temperature. On shutdown of conveyor #1, the screen will stop; however, the cone crusher will continue to run. A conditional interlock is provided to allow the screen to start without conveyor #1 running, provided the apron feeder and the jaw crusher are stopped. This conditional interlock is to allow for a general start-up of the Crushing Circuit.

A flowsheet wouldgraphically illustrate the interlocks between all the equipment in the Crushing Circuit. Conveyor #3 is similar to conveyor #2 with respect to speed, pull-cord, and plugged chute switches. On a high fine ore bin level the apron feeder is shut down immediately, and after 5-10 minutes (software adjustable) conveyor #3 shuts down, followed by the entire Crushing Circuit, through the respective equipment interlocks. This time lapse should allow for material to empty from all the equipment in the Crushing Plant.

The Crushing Plant is equipped with a 12000 CFM wet dust scrubber and a 10 HP scrubber bottoms pump which run together in automatic mode, and will shut conveyor #3 down after a delay of 5 minutes if this system is stopped (subsequent interlocks will shut down the entire circuit except for the jaw and cone crushers) . Pick up points for the dust collection system are: discharge of the apron feeder, grizzly discharge chute at conveyor #1, jaw crusher discharge chute at conveyor #1, cone crusher discharge chute at conveyor #1, transfer point between conveyors #1 and #2, screen feed chute, cone crusher feed chute, and the screen undersize discharge chute at conveyor #3. The collector empties its contents in to the 10 HP 2 vertical scrubber bottoms pump, where reclaim water is added. Level is maintained in the pumpbox by a float and link control valve. A portion of the pump discharge recirculates back to the dust collector, the remainder is pumped to the cyclone feed pumpbox.

The Crushing Plant is also equipped with a 5 tonneoverhead crane and a 15 HP 2 vertical sump pump and sump. The sump pump operates automatically on ahigh/low float level control, or manually. The sump pump also discharges to the cyclone feed pump-box or to the grinding area sump.Should a fire occur in the crushing plant, for safety, a flowswitch in the fire water pipe will stop conveyor #3, hence theentire Crushing Plant.

cone crusher - tips of operation and regular maintenance | hxjq

cone crusher - tips of operation and regular maintenance | hxjq

During the using process, if the worker operates and maintains the crusher according to correct standards, it will have great significance in normal production, output, quality, service life, working efficiency and the prevention of accidents, etc.

At present, the common cone crushers are mainly the single toggle cone crusher and compound cone crusher (Symons cone crusher). Although both types of cone crushers are totally different, they have the same operation procedure.

The operation procedure of cone crusher can be divided into four stages: before the start, at start-up, at run time and turning-off time. All conditions should be paid attention in each stage, and the potential problems can be found and solved timely and the service time can be prolonged.

Turn on the lubricating oil pump to run for three to five minutes. After everything runs well, turn on the crusher as required. After the crusher idles for one to two minutes, confirm that all things are well, and feed the rocks or stones.

During the crushing process, there is a great impact on the concave which makes the filled zinc layer be out of shape. Therefore, the U-type bolt should be tightened frequently to make the concave fix and avoid concave from deformation.

The mantle is fixed by the upper bolt of the main shaft. The looseness of the bolt can make the mantle unstable, even the filled layer may fall off to cause downtime. Hence, the bolts should be often checked and fixed to avoid looseness.

The spherical bearing should be installed in the borehole of crusher closely. After a long period of working, the tightness of crusher' parts can be broken. The tightness of spherical bearing must be checked frequently, and the oil gallery of the spherical bearing should be kept clean.

Water seal is the equipment for preventing crusher from dust, which is very important to the normal operation of cone crusher. Therefore, daily maintenance and checking its integrality are very necessary.

Through the study of this article, you must have a deeper understanding of the operation and maintenance of the cone crusher. In the case of the above-mentioned failure of the crusher, the problem is analyzed and solved by referring to the method given in this article.

crushing plant startup sequence & procedure

crushing plant startup sequence & procedure

All the Crushing Plant equipment is interlocked, except for the sump pump, and therefore, the plant must be started from the fine ore bin back. The dust collector and scrubber bottoms pump are interlocked together, and must be started prior to other equipment. The sump pump should be placed in AUTO. The drives should be started in this order:

Normal Crushing Plant Operation After the crushing plant has been brought up to normal operating conditions the operator should attempt to even out the feed to the jaw crusher to the design tonnage of 60 mtph. This is achieved by ensuring that the feed to the crusher maintains an essentially full chamber without ore spilling out. Adjust the speed of the apron feeder with to increase or decrease the feed rate to the jaw crusher and ultimately to the crushing circuit.

The product from both crushers should be visually checked to ensure that each crusher is producing the desired product. If the jaw crusher product increases in size, the cone crusher may become overloaded. Similarly, if the cone crusher product increases in size, the circulating load around the cone crusher will increase, consequently, increasing the load on the cone crusher and decreasing throughput.

The Crushing Plant operator must monitor the cone crusher power draw displayed on the cone crusher ammeter. The ammeter should show no major fluctuations and should read approximately 100 amps. An excessively high power draw on the cone crusher indicates the cone is being overloaded, which may be due to a high feed rate or a blinded screen.

The operator must pay close attention to the cone crusher lube system. A low pressure alarm will sound if there is an abnormally low oil pressure. If this alarm sounds, the crusher will shut down after a timed delay. If the crusher is allowed to operate longer than 2 minutes after the loss of oil pressure, serious damage to the crusher may result. If the pressure gauge indicates pressure above the normal operating pressure, shut down the cone crusher and investigate the problem. Likewise, a high temperature alarm will sound if there is an abnormally high oil temperature in the oil return line. Shutdown the crusher and investigate if the temperature of the oil pipes seems excessive. Low oil pressure or high oil temperature may be caused by several conditions;insufficient oil supply in the lubrication system, a broken oil feed line, oil pump failure or excessive bearing wear in the crusher. Either condition must be thoroughly investigated as to the cause of the alarm.

Although there is no variable control of the beltconveyors in the Crushing Plant, the operator should regularly check conveyor discharge chutes to ensure there is no undue buildup of material. This is especially important if the feedmaterial is clay-like or excessively wet.

The Crushing Plant operator must ensure that the dust scrubber has an adequate supply of reclaim water and monitor flow-meter to ensure that the proper amount of water isbeing recirculated through the scrubber. Under normal conditions, the dust scrubber requires a minimum recirculation of 8 to 10 cubic meters per hour. A lower flowrate will ultimately cause excessive wear on the scrubber and a higher flowrate is a waste of reclaim water and may hinder operation of the grinding circuit.

cone crusher - an overview | sciencedirect topics

cone crusher - an overview | sciencedirect topics

Cone crushers were originally designed and developed by Symons around 1920 and therefore are often described as Symons cone crushers. As the mechanisms 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. Figure5.3 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 help 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 is 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 Table5.4 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 [5]. 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 to 2100mm. These crushers are always operated under choke feed conditions. The feed size is less than 50mm and therefore the product size is usually less than 69mm.

Maintenance of the wear components in both gyratory and cone crushers is one of the major operating costs. Wear monitoring is possible using a Faro Arm (Figure 6.10), which is a portable coordinate measurement machine. Ultrasonic profiling is also used. A more advanced system using a laser scanner tool to profile the mantle and concave produces a 3D image of the crushing chamber (Erikson, 2014). Some of the benefits of the liner profiling systems include: improved prediction of mantle and concave liner replacement; identifying asymmetric and high wear areas; measurement of open and closed side settings; and quantifying wear life with competing liner alloys.

Various types of rock fracture occur at different loading rates. For example, rock destruction by a boring machine, a jaw or cone crusher, and a grinding roll machine are within the extent of low loading rates, often called quasistatic loading condition. On the contrary, rock fracture in percussive drilling and blasting happens under high loading rates, usually named dynamic loading condition. This chapter presents loading rate effects on rock strengths, rock fracture toughness, rock fragmentation, energy partitioning, and energy efficiency. Finally, some of engineering applications of loading rate effects are discussed.

In Chapter4, we have already seen the mechanism of crushing in a jaw crusher. Considering it further we can see that when a single particle, marked 1 in Figure11.5a, is nipped between the jaws of a jaw crusher the particle breaks producing fragments, marked 2 and 3 in Figure11.5b. Particles marked 2 are larger than the open set on the crusher and are retained for crushing on the next cycle. Particles of size 3, smaller than the open set of the crusher, can travel down faster and occupy or pass through the lower portion of the crusher while the jaw swings away. In the next cycle the probability of the larger particles (size 2) breaking is greater than the smaller sized particle 3. In the following cycle, therefore, particle size 2 is likely to disappear preferentially and the progeny joins the rest of thesmaller size particles indicated as 3 in Figure11.5c. In the figures, the position of the crushed particles that do not exist after comminution is shaded white (merely to indicate the positions they had occupied before comminution). Particles that have been crushed and travelled down are shown in grey. The figure clearly illustrates the mechanism of crushing and the classification that takes place within the breaking zone during the process, as also illustrated in Figure11.4. This type of breakage process occurs within a jaw crusher, gyratory crusher, roll crusher and rod mills. Equation (11.19) then is a description of the crusher model.

In practice however, instead of a single particle, the feed consists of a combination of particles present in several size fractions. The probability of breakage of some relatively larger sized particles in preference to smaller particles has already been mentioned. For completeness, the curve for the probability of breakage of different particle sizes is again shown in Figure11.6. It can be seen that for particle sizes ranging between 0 K1, the probability of breakage is zero as the particles are too small. Sizes between K1 and K2 are assumed to break according a parabolic curve. Particle sizes greater than K2 would always be broken. According to Whiten [16], this classification function Ci, representing the probability of a particle of size di entering the breakage stage of the crusher, may be expressed as

The classification function can be readily expressed as a lower triangular matrix [1,16] where the elements represent the proportion of particles in each size interval that would break. To construct a mathematical model to relate product and feed sizes where the crusher feed contains a proportion of particles which are smaller than the closed set and hence will pass through the crusher with little or no breakage, Whiten [16] advocated a crusher model as shown in Figure11.7.

The considerations in Figure11.7 are similar to the general model for size reduction illustrated in Figure11.4 except in this case the feed is initially directed to a classifier, which eliminates particle sizes less than K1. The coarse classifier product then enters the crushing zone. Thus, only the crushable larger size material enters the crusher zone. The crusher product iscombined with the main feed and the process repeated. The undersize from the classifier is the product.

While considering the above aspects of a model of crushers, it is important to remember that the size reduction process in commercial operations is continuous over long periods of time. In actual practice, therefore, the same operation is repeated over long periods, so the general expression for product size must take this factor into account. Hence, a parameter v is introduced to represent the number of cycles of operation. As all cycles are assumed identical the general model given in Equation (11.31) should, therefore, be modified as

Multiple vectors B C written in matrix form:BC=0.580000.200.60000.120.180.6100.040.090.20.571.000000.700000.4500000=0581+00+00+000.580+00.7+00+000580+00+00.45+000.580+00+00+000.21+0.60+00+000.20+0.60.7+00+000.20+0.60+00.45+000.20+0.60+00+000.121+0.180+0.610+000.120+0.180.7+0.610+000.120+0.180+0.610.45+000.120+0.180+0.610+000.041+0.090+0.20+0.5700.040+0.090.7+0.20+0.5700.040+0.090+0.20.45+0.5700.040+0.090+0.20+0.570=0.580000.20.42000.120.1260.274500.040.0630.090

Now determine (I B C) and (I C)(IBC)=10.5800000000.210.42000000.1200.12610.27450000.0400.06300.0910=0.420000.20.58000.120.1260.725500.040.0630.091and(IC)=000000.300000.5500001

Now find the values of x1, x2, x3 and x4 as(0.42x1)+(0x2)+(0x3)+(0x4)=10,thereforex1=23.8(0.2x1)+(0.58x2)+(0x3)+(0x4)=33,thereforex2=65.1(0.12x1)+(0.126x2)+(0.7255x3)+(0x4)=32,thereforex3=59.4(0.04x1)+(0.063x2)+(0.09x3)+(1x4)=20,thereforex4=30.4

In this process, mined quartz is crushed into pieces using crushing/smashing equipment. Generally, the quartz smashing plant comprises a jaw smasher, a cone crusher, an impact smasher, a vibrating feeder, a vibrating screen, and a belt conveyor. The vibrating feeder feeds materials to the jaw crusher for essential crushing. At that point, the yielding material from the jaw crusher is moved to a cone crusher for optional crushing, and afterward to effect for the third time crushing. As part of next process, the squashed quartz is moved to a vibrating screen for sieving to various sizes.

Crushers are widely used as a primary stage to produce the particulate product finer than about 50100mm. They are classified as jaw, gyratory, and cone crushers based on compression, cutter mill based on shear, and hammer crusher based on impact.

A jaw crusher consists essentially of two crushing plates, inclined to each other forming a horizontal opening by their lower borders. Material is crushed between a fixed and a movable plate by reciprocating pressure until the crushed product becomes small enough to pass through the gap between the crushing plates. Jaw crushers find a wide application for brittle materials. For example, they are used for comminution of porous copper cake. A Fritsch jaw crusher with maximal feed size 95mm, final fineness (depends on gap setting) 0.315mm, and maximal continuous throughput 250Kg/h is shown in Fig. 2.8.

A gyratory crusher includes a solid cone set on a revolving shaft and placed within a hollow body, which has conical or vertical sloping sides. Material is crushed when the crushing surfaces approach each other and the crushed products fall through the discharging opening.

Hammer crushers are used either as a one-step primary crusher or as a secondary crusher for products from a primary crusher. They are widely used for crushing hard metal scrap for different hard metal recycling processes. Pivoted hammers are pendulous, mounted on the horizontal axes symmetrically located along the perimeter of a rotor. Crushing takes place by the impact of material pieces with the high speed moving hammers and by contact with breaker plates. A cylindrical grating or screen is placed beneath the rotor. Materials are reduced to a size small enough to pass through the openings of the grating or screen. The size of the product can be regulated by changing the spacing of the grate bars or the opening of the screen.

The feature of the hammer crushers is the appearance of elevated pressure of air in the discharging unit of the crusher and underpressure in the zone around the shaft close to the inside surface of the body side walls. Thus, the hammer crushers also act as high-pressure, forced-draught fans. This may lead to environmental pollution and product losses in fine powder fractions. A design for a hammer crusher (Fig. 2.9) essentially allows a decrease of the elevated pressure of air in the crusher discharging unit [5]. The A-zone beneath the screen is communicated through the hollow ribs and openings in the body side walls with the B-zone around the shaft close to the inside surface of body side walls. As a result, the circulation of suspended matter in the gas between A and B zones is established and the high pressure of air in the discharging unit of crusher is reduced.

Crushers are widely used as a primary stage to produce the particulate product finer than about 50100 mm in size. They are classified as jaw, gyratory and cone crushers based on compression, cutter mill based on shear and hammer crusher based on impact.

A jaw crusher consists essentially of two crushing plates, inclined to each other forming a horizontal opening by their lower borders. Material is crushed between a fixed and a movable plate by reciprocating pressure until the crushed product becomes small enough to pass through the gap between the crushing plates. Jaw crushers find a wide application for brittle materials. For example, they are used for comminution of porous copper cake.

A gyratory crusher includes a solid cone set on a revolving shaft and placed within a hollow body, which has conical or vertical sloping sides. Material is crushed when the crushing surfaces approach each other and the crushed products fall through the discharging opening.

Hammer crushers are used either as a one-step primary crusher or as a secondary crusher for products from a primary crusher. They are widely used for crushing of hard metal scrap for different hard metal recycling processes.

Pivoted hammers are pendulous, mounted on the horizontal axes symmetrically located along the perimeter of a rotor and crushing takes place by the impact of material pieces with the high speed moving hammers and by contact with breaker plates. A cylindrical grating or screen is placed beneath the rotor. Materials are reduced to a size small enough pass through the openings of the grating or screen. The size of product can be regulated by changing the spacing of the grate bars or the opening of the screen.

The feature of the hammer crushers is the appearance of elevated pressure of air in the discharging unit of the crusher and underpressure in the zone around of the shaft close to the inside surface of the body side walls. Thus, the hammer crushers also act as high-pressure forced-draught fans. This may lead to environmental pollution and product losses in fine powder fractions.

A design for a hammer crusher (Figure 2.6) allows essentially a decrease of the elevated pressure of air in the crusher discharging unit [5]. The A-zone beneath the screen is communicated through the hollow ribs and openings in the body side walls with the B-zone around the shaft close to the inside surface of body side walls. As a result, circulation of suspended matter in the gas between A- and B-zones is established and high pressure of air in the discharging unit of crusher is reduced.

For a particular operation where the ore size is known, it is necessary to estimate the diameter of rolls required for a specific degree of size reduction. To estimate the roll diameter, it is convenient to assume that the particle to be crushed is spherical and roll surfaces are smooth. Figure6.2 shows a spherical particle about to enter the crushing zone of a roll crusher and is about to be nipped. For rolls that have equal radius and length, tangents drawn at the point of contact of the particle and the two rolls meet to form the nip angle (2). From simple geometry it can be seen that for a particle of size d, nipped between two rolls of radius R:

Equation (6.2) indicates that to estimate the radius R of the roll, the nip angle is required. The nip angle on its part will depend on the coefficient of friction, , between the roll surface and the particle surface. To estimate the coefficient of friction, consider a compressive force, F, exerted by the rolls on the particle just prior to crushing, operating normal to the roll surface, at the point of contact, and the frictional force between the roll and particle acting along a tangent to the roll surface at the point of contact. The frictional force is a function of the compressive force F and is given by the expression, F. If we consider the vertical components of these forces, and neglect the force due to gravity, then it can be seen that at the point of contact (Figure6.2) for the particle to be just nipped by the rolls, the equilibrium conditions apply where

As the friction coefficient is roughly between 0.20 and 0.30, the nip angle has a value of about 1117. However, when the rolls are in motion the friction characteristics between the ore particle will depend on the speed of the rolls. According to Wills [6], the speed is related to the kinetic coefficient of friction of the revolving rolls, K, by the relation

Equation (6.4) shows that the K values decrease slightly with increasing speed. For speed changes between 150 and 200rpm and ranging from 0.2 to 0.3, the value of K changes between 0.037 and 0.056. Equation (6.2) can be used to select the size of roll crushers for specific requirements. For nip angles between 11 and 17, Figure6.3 indicates the roll sizes calculated for different maximum feed sizes for a set of 12.5mm.

The maximum particle size of a limestone sample received from a cone crusher was 2.5cm. It was required to further crush it down to 0.5cm in a roll crusher with smooth rolls. The friction coefficient between steel and particles was 0.25, if the rolls were set at 6.3mm and both revolved to crush, estimate the diameter of the rolls.

It is generally observed that rolls can accept particles sizes larger than the calculated diameters and larger nip angles when the rate of entry of feed in crushing zone is comparable with the speed of rotation of the rolls.

Jaw crushers are mainly used as primary crushers to produce material that can be transported by belt conveyors to the next crushing stages. The crushing process takes place between a fixed jaw and a moving jaw. The moving jaw dies are mounted on a pitman that has a reciprocating motion. The jaw dies must be replaced regularly due to wear. Figure 8.1 shows two basic types of jaw crushers: single toggle and double toggle. In the single toggle jaw crusher, an eccentric shaft is installed on the top of the crusher. Shaft rotation causes, along with the toggle plate, a compressive action of the moving jaw. A double toggle crusher has, basically, two shafts and two toggle plates. The first shaft is a pivoting shaft on the top of the crusher, while the other is an eccentric shaft that drives both toggle plates. The moving jaw has a pure reciprocating motion toward the fixed jaw. The crushing force is doubled compared to single toggle crushers and it can crush very hard ores. The jaw crusher is reliable and robust and therefore quite popular in primary crushing plants. The capacity of jaw crushers is limited, so they are typically used for small or medium projects up to approximately 1600t/h. Vibrating screens are often placed ahead of the jaw crushers to remove undersize material, or scalp the feed, and thereby increase the capacity of the primary crushing operation.

Both cone and gyratory crushers, as shown in Figure 8.2, have an oscillating shaft. The material is crushed in a crushing cavity, between an external fixed element (bowl liner) and an internal moving element (mantle) mounted on the oscillating shaft assembly. An eccentric shaft rotated by a gear and pinion produces the oscillating movement of the main shaft. The eccentricity causes the cone head to oscillate between the open side setting (o.s.s.) and closed side setting (c.s.s.). In addition to c.s.s., eccentricity is one of the major factors that determine the capacity of gyratory and cone crushers. The fragmentation of the material results from the continuous compression that takes place between the mantle and bowl liners. An additional crushing effect occurs between the compressed particles, resulting in less wear of the liners. This is also called interparticle crushing. The gyratory crushers are equipped with a hydraulic setting adjustment system, which adjusts c.s.s. and thus affects product size distribution. Depending on cone type, the c.s.s. setting can be adjusted in two ways. The first way is by rotating the bowl against the threads so that the vertical position of the outer wear part (concave) is changed. One advantage of this adjustment type is that the liners wear more evenly. Another principle of setting adjustment is by lifting/lowering the main shaft. An advantage of this is that adjustment can be done continuously under load. To optimize operating costs and improve the product shape, as a rule of thumb, it is recommended that cones always be choke-fed, meaning that the cavity should be as full of rock material as possible. This can be easily achieved by using a stockpile or a silo to regulate the inevitable fluctuation of feed material flow. Level monitoring devices that detect the maximum and minimum levels of the material are used to start and stop the feed of material to the crusher as needed.

Primary gyratory crushers are used in the primary crushing stage. Compared to the cone type crusher, a gyratory crusher has a crushing chamber designed to accept feed material of a relatively large size in relation to the mantle diameter. The primary gyratory crusher offers high capacity thanks to its generously dimensioned circular discharge opening (which provides a much larger area than that of the jaw crusher) and the continuous operation principle (while the reciprocating motion of the jaw crusher produces a batch crushing action). The gyratory crusher has capacities starting from 1200 to above 5000t/h. To have a feed opening corresponding to that of a jaw crusher, the primary gyratory crusher must be much taller and heavier. Therefore, primary gyratories require quite a massive foundation.

The cone crusher is a modified gyratory crusher. The essential difference is that the shorter spindle of the cone crusher is not suspended, as in the gyratory, but is supported in a curved, universal bearing below the gyratory head or cone (Figure 8.2). Power is transmitted from the source to the countershaft to a V-belt or direct drive. The countershaft has a bevel pinion pressed and keyed to it and drives the gear on the eccentric assembly. The eccentric assembly has a tapered, offset bore and provides the means whereby the head and main shaft follow an eccentric path during each cycle of rotation. Cone crushers are used for intermediate and fine crushing after primary crushing. The key factor for the performance of a cone type secondary crusher is the profile of the crushing chamber or cavity. Therefore, there is normally a range of standard cavities available for each crusher, to allow selection of the appropriate cavity for the feed material in question.

The main task of renovation construction waste handling is the separation of lightweight impurities and construction waste. The rolling crusher with opposite rollers is capable of crushing the brittle debris and compressing the lightweight materials by the low-speed and high-pressure extrusion of the two opposite rollers. As the gap between the opposite rollers, rotation speed, and pressure are all adjustable, materials of different scales in renovation construction waste can be handled.

The concrete C&D waste recycling process of impact crusher+cone crusher+hoop-roller grinder is also capable of handling brick waste. In general, the secondary crushing using the cone crusher in this process with an enclosed crusher is a process of multicrushing, and the water content of waste will become an important affecting factor. The wet waste will be adhered on the wall of the grinding chamber, and the crushing efficiency and waste discharging will be affected. When the climate is humid, only coarse impact crushing is performed and in this case the crushed materials are used for roadbase materials. Otherwise, three consecutive crushings are performed and the recycled coarse aggregate, fine aggregate, and powder materials are collected, respectively.

The brick and concrete C&D waste recycling process of impact crusher+rolling crusher+hoop-roller grinder is also capable of handling the concrete waste. In this case, the water content of waste will not be an important affecting factor. This process is suitable in the regions with wet climates.

The renovation C&D waste recycling process of rolling crusher (coarse/primary crushing)+rolling crusher (intermediate/secondary crushing)+rolling crusher (fine/tertiary crushing) is also capable of handling the two kinds of waste discussed earlier. The particle size of debris is crushed less than 20mm and the lightweight materials are compressed, and they are separated using the drum sieve. The energy consumption is low in this process; however, the shape of products is not good (usually flat and with cracks). There is no problem in roadbase material and raw materials of prefabricated product production. But molders (the rotation of rotors in crusher is used to polish the edge and corner) should be used for premixed concrete and mortar production.

14 cone crusher common problems and how to fix them | m&c

14 cone crusher common problems and how to fix them | m&c

Cone crusher has high crushing ratio, high efficiency, low energy consumption, uniform product size, suitable for medium crushing and fine crushing of various ores and rocks. In the cone crusher working process will encounter a variety of problems, So, we provides 14 common fault causes and solutions!

Table of Contents 1. The oil temperature is too high.2. Oil temperature and pressure rise.3.Oil pressure is low after oil pump is started4.Oil contain lots of fine mud and impurities.5.There is water in the oil6.The vibration of cone crusher is too strong.7. The crushing cone rotates very high.8. The sudden speed of the moving cone accelerates.9. Non-uniform rotation of transmission shaft10. Make splitting sounds.11. The coupling rotates and the crusher does not move.12. The drive shaft produces a strong knock.13. The supporting ring jumps.14. The size of ore discharging increases.

Cause: The quality of the oil is poor or the oil is insufficient; the bearing is damaged; the ambient temperature is high, there is no cooling water or the cooling water pressure is low; the cooler is clogged. Solution: change oil or refuel; change bearings; supply cooling water or increase the pressure of cooling water; clean the cooler.

Causes: water enters the lean oil station; the cooler leaks, and the water pressure is greater than the oil pressure; water supply too much or the return pipe is blocked. Solutions: Clean oil tank and replace oil; repair leakage or replace cooler, reduce water pressure, clean oil tank and replace oil; adjust water supply or clean water return pipe, clean oil tank and replace new oil.

Causes: Cone crusher base is loosening; Difficult-to-break materials enter the crushing chamber, leading to blockage; parts break or wear; poor lubrication makes the spindle tightened by bushing. Solutions: fastening bolts, pouring; controlling the type of feed, strictly forbidding the entry of non-fragments; strictly controlling the amount of feed; stopping the machine to check accessories; replacing damaged parts, repairing oil pumps and pipelines.

Causes: oil shortage or dust in oil between spindle and bushing; insufficient clearance of tapered bushing; wear or manufacturing reasons of bowl bearing bush, contact surface deep to inner circle, conical body sinking. Solutions: overhaul or replace bushings, spindles, etc., and find out the causes of oil shortage, eliminate it; adjust bushing clearance; re-scrape, and meet the requirements.

Causes: serious wear or damage of gears; damage of connection keys; breakage of spindle. Solutions: stop and replace gears, and make meshing clearance meet the requirements; change the connection keys; change the spindle, strengthen iron removal work.

380x cone crusher. Raised to clear to empty out it wont come back down. The open/ close switches work along with clear button. So hyd works. Turn on delivery belt and pull the lube/ hyd button to bring cone down. hyd wont engage. Changed the contacts on the pull button. Nothing. Swap soil nods no go.

The cone crusher can not be restarted immediately when it stops suddenly, so as to avoid secondary damage to the cone crushing production line. First of all, you should find out the reasons for the sudden stop of the cone crusher, there are 5 common reasons:

1. The discharge port of the cone crusher is blocked, too much or uneven feeding will lead to the blockage of the discharge port, resulting in excessive production load of the crushing machine, resulting in the fracture of the fuse and lead to shutdown.

2. Sudden shutdown may also be caused by too low or too high voltage, unstable voltage or easily forcing the cone to break self-protection resulting in shutdown. So be sure to check whether the voltage is normal before turning on.

3. It may be the eccentric shaft problem, the eccentric shaft fixed bushing loose or falling will lead to no gap between the bearing housing and the frame, resulting in the eccentric shaft can not operate, so the cone crusher will stop suddenly.

First of all, before starting up, check to see if there is any residue in the tapered discharge opening, clean it up immediately, and pay attention to control the feeding evenly, not too much or too little.

The second is whether the belt tightness is appropriate, reasonable adjustment to prevent too tight or too loose. In addition, pay attention to the voltage situation to maintain the stability of the voltage.

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