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Crushing Plant Design and Layout Considerations
Ken Boyd, Manager, Material Handling, AMEC Mining & Metals , Vancouver, BC
ABSTRACT
In mining operations, the layout of crushing plants and ancillary equipment and structures is a crucial factor in meeting production requirements while keeping capital and operational costs to a minimum. This paper addresses the critical design parameters as well as the consideration of ore characteristics, geographical location, climatic conditions, expected operational life, expansion potential, safety, environment, and operability and maintainability.
INTRODUCTION
The fundamental goal for the design of a crushing plant is an installation that meets the required production requirements, operates at competitive cost, complies with today’s tough environmental regulations, and can be built at a reasonable price despite the rising costs of equipment, energy and construction labor. The following industry trends must be taken into account:
- Equipment suppliers are offering ever-larger primary crushers, with 1,800 mm (72 in) gyratories expected soon, as well as secondary and tertiary machines of up to 3,000 mm (120 in).
- Rising energy costs are causing owners to increase the integration of mine and mill design, so that they can identify ways of reducing overall electrical power consumption.
- Electronic control of crusher discharge opening and feed rate. With adjustment of a crusher’s discharge opening, as the production continues through an on-line coarse size analysis of the crushed product (digital image analyses). Dance, A. 2001)
- More attention is being paid to the impact on crushing circuit design caused by variations in ore characteristics, size distribution, moisture content, ore grade and climatic conditions.
- Operators have always dreamed of reducing the need for crushing equipment; when SAG mills were first introduced, it was hoped that they would eliminate secondary and tertiary circuits. As it turned out, designers are now adding secondary or pebble crushers to SAG circuits, on both greenfield and retrofit projects, to increase feed rate to the SAG mill. In other words, crushing plants, from primary to quaternary circuits, are here to stay.
There are three main steps in designing a good crushing plant: process design, equipment selection, and layout. The first two are dictated by production requirements and design parameters, but the layout can reflect the input, preferences and operational experience of a number of parties. These can include the owner’s engineering staff, safety personnel, operations and maintenance personnel, equipment manufacturers, and the engineering consultant. Ideally, the consultant combines his knowledge and experience with an understanding of all parties’ needs, to provide a balanced, workable, safe and economic plant design.
DESIGN PARAMETERS
The principal design parameters that drive crushing plant selection and configuration include:
- Production requirements • Capital cost
- Ore characteristics • Safety and environment
- Project location • Life of mine/expansion plans
- Operational considerations • Maintenance requirements
- Climatic conditions
Each of these is addressed in the sections that follow.
Production Requirements The process design criteria define the project’s production requirements, and typically include those shown in Table 1.
Table 1 Production requirements Process Description General Ore Characteristics Operating Schedule General Primary crushing Fines crushing Storage & reclaim
Maximum rock size in the feed Ore types, compressive strengths and abrasion indices Ore specific gravity Ore bulk density Ore moisture, wet season Ore moisture, dry season Angle of repose Angle of withdrawal Angle of surcharge
Days per year Hours per day Nominal annual throughput Mining shifts per day Crushing plant shifts per day System availability and utilization
The flowsheet specifies the nominal design, peak production flow rate, and equipment sizing to handle those capacities. Manufacturers provide ratings for their equipment, preferably based on testwork and/or experience, so a project flowsheet specifies tonnage requirements and the equipment is selected to meet or exceed the capacities. Design criteria can be calculated from a simple spreadsheet as shown in Table 2. Mine haul-truck capacity is an important factor at primary crusher installations, because it is cost-effective to integrate truck cycle time at the crusher station with mine/shovel operations. If a primary crusher dump pocket is undersized and unable to handle the mine’s trucks, then operators must slowly meter the ore into the receiving hopper.
Capital Cost Direct Costs. The largest primary gyratory crushers cost US $2 million or more, while overall crushing plant costs can be as high as $18 million. It’s necessary therefore to estimate crusher installation costs based on equipment costs plus the following direct costs, including construction contractor indirects:
- Earthworks • Mechanical
- Concrete • Electrical
- Structural steel • Instrumentation.
- Architectural
Indirect Costs. Indirect costs can fall within a range of 40 to 60% of the direct costs, and include:
- Construction indirects • Startup and commissioning
- Construction equipment • Freight
- Spare parts/first fill • Taxes/duties
- Engineering, procurement and construction management (EPCM) - Owner’s costs (relocation, hiring and training personnel, permits, licensing fees, etc).
In addition to the above, a contingency to cover unforeseen costs will be in the range of 10 to 20% of the sum of the direct and indirect costs. The designer must be aware of the project-specific costs of all such elements, so that he can monitor costs and promote methods of reducing total installation costs. In some locations, for example, labor and material costs could make a gabion wall more expensive than a poured concrete wall, which has minimal structural backfill.
Ore Characteristics Ore characteristics are a critical element in both crusher selection and plant design. Dry ores require greater provisions for dust suppression and collection, including dust enclosures around screens, sealing on conveyor skirts, and vacuum and wash-down systems. Wet, sticky ores can plug chutes, reduce surge capacity, and decrease the live storage capacity of bins and silos. To address this problem, chutes must be easily accessible for clean-up, and large feeder openings must be provided for bins, silos and tunnels. If it is practical to obtain representative ore samples, it is prudent to have testwork conducted to establish ore flow properties, which will influence design parameters. At virtually all mines, ore characteristics change over time, and it can be costly to “design in” the optimal flexibility required to handle such changes. Some owners stipulate that initial capital investment be kept to a minimum, with design modifications paid for out of the operating budget. This is not always easy to achieve.
Safety and Environment Safety must be designed into all mining facilities. North American mines must comply with local and national regulations such as OSHA, MSHA, the Mines Act and the WCB. The modern plant includes safety guards around all moving equipment, and emergency pull-cords on both sides of any conveyors with personnel access. The maintenance department and safety officer must keep these safeguards in working order. Ongoing safety training of plant personnel is imperative, and is considered to be one of the most vital and monitored feature of most mining operations.
Dust emissions must comply with the latest regulations for the jurisdiction. Designers must make provisions for the installation of dust abatement, suppression or collection equipment. Spillages from feeders, chutes and conveyors must be minimized. Spill collection can be “designed in” on feeder installations; chute designs can minimize spillage at receiving and discharge points; and conveyor belts can be widened to be more forgiving (e.g., skirting internal back-to-back width can be reduced to allow the belt more side travel.) Skirting should be extended a minimum of three belt widths past the load point. Rules for conveyor and load point design should be used for guidance only, with transfers custom-designed to suit a particular project. It goes without saying that clean plants have lower operating costs. Crushers, screens and dust-collection fans all contribute to high noise levels. Air-cooled lubrication systems are not only noisy, but often leak oil. Well-balanced, choke-fed crushers, dust- enclosed screens and dust collector fans with silencers can keep noise levels under control. Recirculating water can be used to cool crusher lubrication systems.
Project Location A project’s geographical location, topography, geotechnical conditions, remoteness and climate can all affect crusher plant design. Construction costs are generally much greater at high altitudes, in cold climates and at remote sites. To improve the economics of such locations, modular and pre-assembled structures and plant facilities are used prior to transportation to site. Local labor costs often dictate what material can be best used economically in a particular region; for example, cement structures are much cheaper to erect in Mexico than in Alaska. Remote projects can suffer from difficulties in obtaining spare parts on short notice. Crushing plant design should accordingly provide for laydown and workspace for onsite equipment refurbishment and repair. Where possible, equipment manufacturers should be encouraged to stock and provide spare parts close to the mining operation. Good geotechnical information is essential to crushing plant siting and design. Installing a primary crushing plant on solid rock reduces the cost of concrete and structural steel.
Life of Mine/Expansion Plans The life of the mine is a key element in the design of any crushing plant. Short-term mine lives (three to eight years) require a very careful approach to design, layout and construction. Since the crushing plant’s structure and enclosure can represent the largest single cost element in a primary crushing plant, it is imperative to optimize these structural and construction costs to suit the life of the operation. Perhaps a steel-supported, modular design will be best for short-term operations, since the equipment can be relocated and re-used; while for long-life mines, large concrete structures with fully insulated enclosures might be more economical. In conducting trade-off studies, short-term operations should aim for lower capital cost, while long-life installations should be designed to minimize operating costs and emphasize maintainability. “Operating availability is a function of the design of the processing lines and the ease and type of their maintenance” (Shoemaker and Gould, Modern Mill Design , 1980). Again to quote Shoemaker and Gould, “Increased production of the final product is often more easily and economically attained through expansion than by increased recovery.” Planning for expansion is therefore a consideration in all but the shortest-lived operations. Even at mines with expected lives of only five or six years, it may be necessary to select equipment that can handle anticipated throughput increases. Expansion plans for most crushing plants can be incorporated in the early planning stages at much lower cost than waiting until the mine is up and running before deciding to expand. More and more, operators want to increase primary crusher throughput, especially when they incorporate larger trucks into their mine planning or operations. One manufacturer has modified its 1,067 mm (42 in) and 1,371 mm (54 in) primary crushers to allow for larger rocks and increased
Climatic Conditions Building for cold-weather operations is very challenging, as is designing a plant in a desert environment. This is particularly true when year-round operation is required. Seasonal variations can change ore moisture content, so the crushing plant must be adaptable to changes in the material flow characteristics. Higher moisture requires greater angles of withdrawal, and stone- boxes must be designed to avoid plugging. The crushing plant equipment itself must be adjustable to climatic changes; for example, screen decks must be designed to maintain production, possibly by using wire mesh during the wet season and plastic during the dry. (Vary screen deck types dependent on seasons and material characteristics to achieve maximum passing through deck openings. Climate also dictates the type of plant enclosures required as shown in Figures 1 and 2. Many crushers in milder weather climates or desert areas are installed with an open face and have no enclosures at all.
Figure 1 Teck Cominco, Red Dog Operations, Alaska
Figure 2 Teck Cominco, Red Dog Operations, Alaska - 42” x 65” gyratory
PROCESS DESIGN CRITERIA
Design Criteria Information Typically, the information required to develop crusher process design criteria includes:
- Geographic data • Climatic data
- Civil design criteria
- Structural design criteria
- Process design data (process description, ore characteristics)
- Mechanical design criteria • Electrical/instrumentation design criteria.
Flowsheet Some sample flowsheets are provided in Figures 3, 4, and 5 showing crusher circuits. Figure 6 shows a typical three stage closed crushing circuit with its ancillary equipment.
Figure 3 Two stage open/closed circuit
Figure 4 Three stage open/closed circuit
SECONDARY CONE CRUSHER
DOUBLE DECK SCREEN
PRODUCT
CLOSED CIRCUIT
COARSE ORE STOCKPILE
PRIMARY CRUSHER
OPEN CIRCUIT
SECONDARY CONE CRUSHER
DOUBLE DECK SCREEN
PRODUCT
CLOSED CIRCUIT
COARSE ORE STOCKPILE
PRIMARY CRUSHER
OPEN CIRCUIT
DOUBLE DECK SCREEN
SECONDARY CONE CRUSHER
PRODUCT
COARSE ORE STOCKPILE
PRIMARY CRUSHER
TERTIARY CONE CRUSHER
3 STAGE CLOSED CIRCUIT
TERTIARY CONE CRUSHER
DOUBLE DECK SCREEN
DOUBLE DECK SCREEN
OPEN CIRCUIT
OPEN CIRCUIT
DOUBLE DECK SCREEN
SECONDARY CONE CRUSHER
PRODUCT
COARSE ORE STOCKPILE
PRIMARY CRUSHER
TERTIARY CONE CRUSHER
3 STAGE CLOSED CIRCUIT
TERTIARY CONE CRUSHER
DOUBLE DECK SCREEN
DOUBLE DECK SCREEN
OPEN CIRCUIT
OPEN CIRCUIT
10
Figure 6 Three stage crushing closed circuit
PLANT LAYOUT AND DESIGN
A well-designed plant layout balances the capital versus operating cost over mine life. Buildings, infrastructure, and major equipment items, represent the major cost elements of a crushing plant. The designer must prepare a layout that suits the design criteria, flowsheet and selected equipment in the most economical possible configuration. It’s important to keep structural costs down, to design for ease of maintenance and operation, and to combine best practices with advances in fabrication and erection. Input from an experienced mining plant structural engineer can be very helpful. Crushing circuits and ancillaries have not changed a great deal over the years, so “Keep It Simple” is still the best way to design a plant. Owners may wonder why the design of head chutes hasn’t changed in decades, but the explanation is simple: it’s because the old, well-proven approaches still work best. On the other hand, it’s dangerous to assume that a layout that works well at one mine will work just as well, or at all, at another. Provisions must be made for the replacement of wear parts (e.g., install man-doors on head chutes with flood lighting inside the chute.) Faster part replacement means less downtime. Layout tools can include cut-and-paste arrangements, 2D arrangements fitted onto site topography, or 3D CAD to superimpose the design on the selected site. The choice of tool depends on whether the work is being done at the prefeasibility, feasibility or detailed engineering level, as well as on the accuracy required of any associated cost estimate. The best designs are developed using basic approaches and tools: site visits, discussions with mine personnel, sketches, and cut- and-paste layouts. This writer believes that only after the initial concepts have been developed and optimized does 3D CAD have a role to play. Different industries have different approaches to crushing plant design. The standard approach in the oil sands industry is to use MicroStation 3D CAD from the start; in some cases, the finalization of a system design (hopper, feeder, sizer crusher, and takeaway conveyor) has taken as much as two years, because of the uniqueness of the application. A similar design in the hard-rock mining industry takes from four to six months.
THE PRIMARY CRUSHER
Primary crushers, no matter what type, must all meet the design parameters described earlier. Design details that are fundamental to the layout of gyratory crusher plants are listed in the sections that follow. Some of these details are applicable to other types of crushers as well. A typical in-ground gyratory crusher layout is shown in Figures 7 and 8. Figure 9 breaks this plant down into major areas that are identified as “project specific” or “necessary”.
Figure 9 Gyratory broken into necessary process portions and project specific portions
PROJECT SPECIFIC
NECESSARY
NECESSARY
PROJECT SPECIFIC
NECESSARY
PROJECT SPECIFIC
PROJECT SPECIFIC
NECESSARY
NECESSARY
PROJECT SPECIFIC
NECESSARY
PROJECT SPECIFIC
A typical jaw crusher plant is shown in Figure 10 and Figure 11 shows a typical underground jaw crusher layout. A typical low speed roll sizer plant is shown in Figure 12.
Figure 10 Typical jaw crusher plant enclosed
Figure 11 Typical underground jaw crusher installation
Upper Superstructure
- It is always a challenge to size the crane. Should it be used to install the crusher, or to just service the components of the crusher? The main service hook doesn’t need to travel any further than the top of the crusher; beyond this point, slings can be added to lift anything at lower levels.
- Crane main hook speed should be slow, for inserting the main shaft.
- Always prepare a hook coverage plan to check all areas of crane service.
- Crane maintenance access should include stairs and a platform to service an overhead bridge crane.
- Choose the type of crane, overhead bridge, jib, gantry or mobile crane required to meet project requirements.
- A well-ventilated crusher control room is required.
- There must be a washroom, with or without potable water.
- The electrical room can be located at the upper or lower level; keep high-voltage runs short.
- The location of the dust collector should consider operating lengths of ductwork..
- Two main shaft supports are required, for the shaft in use and a spare. Storage must be provided for both. The spare shaft may be stored near the crusher or in the truck or maintenance shop.
- Provision may be required for a furnace and zincing, although most of today’s crushers use epoxy instead.
- Provide a maintenance laydown area.
- Locate the plant air compressor in a room away from dusty areas.
Receiving Hopper Area
- Determine whether a grizzly is required in the receiving hopper area. This is very expensive in gyratory installations, but is frequently used in jaw crusher installations.
- A splitter may be required in the receiving hopper area, to reduce impact on the spider, particularly in the expectation of large run-of-mine material. Some crusher manufacturers request that protection be provided from direct rock impacts on the spider. The design of a splitter remains a very controversial design subject and has to be reviewed for each project, remembering that any splitter installation can be very expensive. Investigate the design of the receiving hopper relative to where the material impacts as it leaves the truck.
- Well-hatch covers should be fixed-hinge on one side so they won’t accidentally drop to a lower level.
- To minimize dust emission, a vertical dump hopper spray system is best, with up to ten sprays per header. This provides greater distance for dust to pass through.
- A receiving hopper dust-hood plenum is required for plants using dust collection.
- Care should be exercised in determining whether receiver hopper liners are required, and if so, how many and what type. These items are costly. Often it is preferable to install only the steel inserts in the concrete for attaching liners. When the hopper deadbeds are formed, liners need to be applied only on exposed areas.
- Design a simple, easily removed, drop-in circular steel seal for the crusher and dump hopper. A rubber lining will prevent or minimize water leakage.
- Installing a receiving hopper access door at the crusher seal level allows for quick access when concaves are being changed.
- The ability to easily dig out the upper crusher pocket is critical. A long length of stud link chain can be placed on the pocket floor with one end exposed for lifting out and breaking up the stone boxed material in the pocket.
- Rock breaker location is critical to provide reach in all areas of the hopper, and also for concave removal. Ensure that the breaker impact head can be parked in the vertical position out of the way of truck dumping.
- Determine whether the rock breaker should be remotely and/or locally controlled.
- The control room operator should be able to see down into the dump box, preferably through a window installed to the floor. He should be able to see approaching trucks.
- The operator should have access to washroom facilities.
- Truck bollards can be of concrete, old tires or tree trunks. The bollards should be located so they will always deflect the truck body away from any structural columns.
Crusher Floor Level
- A walkway platform should be installed around the crusher for easy spider removal.
- A built-in circular monorail under the concrete floor level at the top of the crusher will provide support for a trolley support air hammer, which can be used to remove or install the spider nuts
- Choose countershaft, in-line drive versus V-belt drive and clutch.
- The spider lube system should normally be located at the crusher floor level.
- The air-seal compressor can be located on the crusher floor.
- The balance cylinder should be located close to the crusher, with maximum pipe bend radii for ease of quick response. Provisions must be made for oil relief collection.
Surge Bin Area
- The surge bin access door should be split horizontally on one side, to allow easy man- access to one side without opening the whole door.
- For the crusher discharge opening, tapered concrete with a welded AR plate is preferred.
- Air cannon discharge points must be pre-designed. Locate the air receivers and valves out side the surge bin.
- Level detectors should be installed at high and low points in the surge pocket.
- For the eccentric trolley, a hung design is best, complete with a man-access platform at the top of trolley to permit servicing the crusher hydraulic cylinder and eccentric.
- Surge pocket withdrawal opening liners should be made in a minimum number of large pieces for ease of removal. Drop-in design is best, without bolts. Liners can be lifted with a sling from the service crane hook through the crusher.
- The surge pocket opening slot should be made as long as practical to maximize live capacity.
- At a minimum, one truckload’s worth of live capacity should be provided, but a capacity of 1.5 or 2 truckloads is better. Some plants are designed with no surge bin under the crusher, with a wide, high-speed take-away conveyor to take the surge (flush rate) to a nearby stockpile or to a external surge bin.
- Install floodlights in the surge pocket to facilitate inspection and maintenance.
- Provide two pick-up openings through the crusher floor level for dust collection at the back of the crusher.
- Provide low-level protection for the surge feeder, possibly gamma detectors. This maintains a bed depth of material to protect the feeder from material falling directly on it.
- If possible, allow for access by a “Bobcat” for cleanup on both sides of the conveyor and at the lower floor level.
- Provide dust collection measures at the conveyor (hood, plenums or sprays).
- Try to have the floor slope down and self-drain to an outside sump, to eliminate sump pumps within the plant structure.
- Keep good clearance under the conveyor tail pulley (a minimum of 400 mm).
- Provide walkway access to service the conveyor skirting.
Electrical
- The electrical MCC/transformer electrical rooms can be located at the top or bottom of a crusher plant.
- Electrical cable tray routing and orientation should be checked by the mechanical process engineer. Vertical trays should be used to eliminate collection of spilled material in the trays.
- If the substation/electrical room is at the surface level, ensure there is no possibility of damage from impact from haul trucks.
Structural Considerations
- Provide easy stair access to each level.
- Provide access to both sides of the take-away conveyor.
- Braces and structures must be located away from equipment service and maintenance areas.
- Primary crushing plant enclosure costs can represent up to two-thirds the capital cost of a crusher station. It is therefore very important to select the most economical structure for the support of the crusher and ancillary equipment. There are many approaches: total concrete structures, round concrete structures, a mixture of concrete and steel, and reinforced earth structures with steel levels. The designer should spend considerable effort on selecting a structure that best suits the design parameters outlined above.
Dust Collection/Suppression
- There are many choices for dust collection/suppression systems, including bag filters, scrubbers, cartridge collectors, surfactants, water sprays and sonic fog. Whether one system or a combination is selected, care must be taken to provide service and maintenance access.
- Control, lube, compressor and electrical rooms should all be well-ventilated.
- Surge bins must include collection hoods.
- The take-away conveyor should have provisions for dust collection/suppression.
- Determine whether dust-collector air must be preheated in cold climates.
- A collector fan silencer should be considered, as fan noise can be excessive in closed areas.
- If an aircooling system is selected for crusher-oil, it will require venting for hot-air evacuation.
Crusher Installations A summary of previous gyratory crusher installations is shown in Table 3.
Table 3 Primary crusher plant installations M in e Locat i o n Cru sh er M fg Q t y Year In st alled
Pro d u ct S i ze
Normal Cap acit y
S ervi ce Cran e
Ap p ro x. O verall H ei g h t
Ap p ro x. Cru sh er Flr
Ap p ro x. Con cret e st p h st on s ft. sq. ft. @ cu. yd s Bet hlehem Co pper
Highland Valley, BC
42 x 54 AC 1 1962 6" 700 40/5 51 600 3280 E ndako E ndako , BC 42 x 54 AC 1 1964 7" 1500 50/5 74 1400 1811 Gr anisle T o pley, BC 42 x 54 AC 1 1966 7" 1000 40/5 52 1150 n/ a B. C. Mo ly Alice Ar m, BC 42 x 54 AC 1 1967 5" 750 40/5 56 1300 n/ a Mar co pper P hillipines 42 x 54 AC/Ko bi
1 1969 7" 1500 35/5 74 2500 n/ a Bell Co pper Babine Lake, BC 42 x 54 AC 1 1972 6. 5" 1500 45/11 70 2300 2561 Aft o n Kamlo o ps, BC 42 x 54 AC 1 1977 8" 2000 35/5 70 1680 2120
42" (1)
E quit y Silver Ho ust o n, BC 42 x 54 AC 1 1980 n/ a n/ a 35/5 70 1600 2054 Gibr alt ar McLeese Lake, BC
54 x 74 AC 1 1972 7" 3000 75/10 82 2600 3260 Rut t an Lynn Lake, MB 54 x 74 AC 1 1972 6" 1800 50/10 81 2100 2388 Aznalco llar Aznalco llar , S pai n
54 x 74 AC/Ko bi
1 1977 8" 1760 11- Jun 81 1950 3270 Gibr alt ar /P it McLeese Lake, BC
54 x 74 AC 1 1979 7" 3000 pit cr ane 63 1662 1500 S imilkameen No. 2
Pr incet o n, BC 54 x 74 AC 1 1979 9" 2880 mo bile 79 1200 n/ a Ranger Ur anium
Jabir u, Aust r alia 54 x 74 AC 1 1981 6. 5" 1400 60/10 86 2100 n/ a Cado min Quar r y
Hint o n, AB 54 x 74 AC 1 1982 6" 2000 44/5 u/g n/ a n/ a
54” (1)
Highmo nt Highland Valley, BC
54 x 74 AC 1 1990 8" 3000 75/10 81 2000 1500 S imilkameen No. 1
Pr incet o n, BC 54 x 74 AC 1 1972 8. 5" 1500 82 mo bile 59 1200 n/ a P alabo r a Mining T win
P halabo r wa, S o ut h Afr ica
54 x 74 AC 2 1966 8" 1265 ea. 75/15 75 6000 8566 Kenneco t t /Ray Ray, AZ 54 x 74 AC 1 1966 8" 1200 60/10 61 2500 n/ a Anaco nda/T win But es
Sahuar it a, AZ 54 x 74 AC 2 1968 8. 5" 2250 ea. 35/ mo bile n/ a n/ a n/ a Bo uganville P apua, New Guinea
54 x 74 AC 2 1972 6" 1750 ea. 60/10 102 5300 9500 I nspir at io n Co ns.
I nspir at io n, AZ 54 x 74 AC 1 1972 7" 1500 75 mo bile 76 1100 1550 Climax Mo ly Hender so n, CO 54 x 74 T r aylo r
1 1976 8"/9" 3000 75/15 111 6100 9475 P alabo r a Mining
P halabo r wa, S o ut h Afr ica
54 x 74 AC 1 1977 8" 1265 80/20 101 cir cular 7680
54” ( 2)
Kenneco t t /Bo nn eville
Salt Lake Cit y, UT
54 x 74 AC 1 n/ a 6" 2000 75/15 139 5800 n/ a Br enda Mines P eachland, BC 60 x 89 AC 1 1969 7" 3500 100/10 87 4200 4300 Cer r o Ver de Ar equipa, P er u 60 x 89 AC 1 1976 7" 3200 90/19 98 1800 n/ a 60" ( 1)^ Rio T int oMiner a Rio T int o , Spain^ 60 x 89 AC^1 1980 n/ a^ n/ a^ 88/11^100 2200 n/ a Cypr us Mining Co r p.
T ho mpso n Cr eek, I D
60 x 89 T r aylo r
1 1982 n/ a 4500 100/30 96 2400 4238 I r o n Or e Co. Lab- Cit y, NF 60 x 89 AC 2 1962/72 7" 4000 ea 75/10 97 10000 n/ a Reser ve Mining Babbit t , MI 60 x 109 AC 1 1955 8. 5" 3000 130 1665 cir cular 11000 Anaco nda/But t e But t e, MT 60 x 89 AC gr izzly feed
1 1971 5. 5" 5000 co mbined
75/20 122 4200 1280 Cit ies S er vice Miami, AZ 60 x 89 T r aylo r
1 1971 8" 3500 80/20 86 2100 4874 Lo r nex Lo gan Lake, BC 60 x 89 AC 1 1972 10" 4000 75 85 2800 6255 Duval Sier r it a T ucso n, AZ 60 x 89 AC 2 1976 6" 2500 ea. 70/20 89 4400 8000
60”
( 2)
So ut her n Per u Cuajo ne, Per u 60 x 89 AC ( gr izzly feed)
1 1976 8" 4000 co mbined
80/20 125 5500 8400
70”
(^) Cdn. Jo hns- Manville
Asbest o s, QE 72 x 93 T r aylo r
1 1972 7. 5" 100/20 106 2100 n/ a
( 1) Wr ight E ngineer s Lt d. I nt er nal st udy o f Pr imar y Cr usher Design, 1982 ( 2) McQuist o n F. W. & S ho emaker R. S. "P r imar y Cr usher Design" "Amer ican I nst it ut e o f Mining, Met allur gical and Pet r o leum E ngineer s" Jan. 1978
