The primary crusher is located in the quarry and consists of a McLanahan 48x72 Shale King Crusher rated at 1,000 TPH (Tons Per Hour). The driving flywheel has a diameter of 2.5 meters and is motor driven through six v-belts. The capacity of the primary crusher had to be increased to 1,250 TPH to produce enough material to serve the wet and both dry lines in the plant. To enable the crusher to operate at the higher capacity, the manufacturer recommended grooving the flywheel for two additional v-belts. To avoid the costs of disassembling, shipping and reassembling, Nesher performed the machining in-place. The operation was performed using portable tools and an auxiliary motor that turned the flywheel for machining the new grooves.
Roll crushers are generally not used as primary crushers for hard ores. Even for softer ores, such as 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 is employed. For close circuit the product is screened with a mesh size much less than the set.
Figure6.4 is a typical set-up where ores crushed in primary and secondary crushers are further reduced in size by a rough roll crusher in an open circuit followed by finer size reduction in a closed circuit by a roll crusher. Such circuits are chosen as the feed size to standard roll crushers normally does not exceed 50mm.
Secondary coal crusher: Used when the coal coming from the supplier is large enough to be handled by a single crusher. The primary crusher converts the feed size to one that is acceptable to the secondary crusher.
Detail descriptions of designs are given of large gyratory crushers that are used as primary crushers to reduce the size of large run-of-mine ore pieces to acceptable sizes. Descriptions of secondary and tertiary cone crushers that usually follow gyratory crushers are also given in detail. The practical method of operation of each type of gyratory crusher is indicated and the various methods of computing operating variables such as speed of gyration, capacities and power consumption given are prescribed by different authors. The methods of calculations are illustrated to obtain optimum operating conditions of different variables of each type using practical examples.
Shale, a low-moisture content soft rock, is quarried, transferred to blending stockpiles before it is reduced by primary crushers and dry-milled to a powder of less than 250m. This powder is homogenized and stored ready for pelletization in manner similar to that used for making aggregate from PFA except that no fuel is added. However, after the pellets have been produced to the appropriate size, which depends on the expansion required, they are compacted and coated with finely powdered limestone. The resulting pellets are spherical with a green strength sufficient for conveying to a three-stage kiln consisting of a pre-heater, expander and cooler. Unlike other aggregates produced from argillaceous materials, the feedstock is reduced to a powder and then reconstituted to form a pellet of predetermined size. The expansion (bloating) is controlled during kilning to produce an aggregate of the required particle density. Different particle densities are produced by controlling the firing temperature and the rotational speed of the kiln. The coating of limestone applied to the green pellet increases the degree of surface vitrification which results in a particle of low permeability. This product gives versatility to the designer for pre-selecting an appropriate concrete density. As Figure7.6 shows, while the particle shape and surface texture of the aggregate remain essentially the same, the internal porosity can be varied according to the bloating required for the specified density.
Mined crushed stone is loaded into trucks or onto conveyors and transported to the processing facility. The broken stone is dumped into a primary crusher where the large rock fragments are broken into smaller sizes. Crushing to the proper size usually occurs in stages because rapid size reduction, accomplished by applying large forces, commonly results in the production of excessive fines (Rollings and Rollings 1996). After primary crushing, the material is run through one or more secondary crushers. These crushers use compression, impact, or shear to break the rock into smaller pieces. The material is screened after each crushing cycle to separate properly sized particles (throughs) from those needing additional crushing (overs). Additional washing, screening, or other processing may be required to remove undesirable material. The material is then stockpiled awaiting shipment.
After mining, sand and gravel may be used as is, which is called bank-run or pit-run gravel, or it may be further processed. The procedures for processing sand and gravel are similar to those for processing crushed stone. The amount of processing depends on the characteristics of the sand and gravel deposit and the intended use. If the gravel deposits contain very large cobbles or boulders, that material may be run through a primary crusher. The material may be run through one or more secondary crushers, then washed, screened, or further processed to remove undesirable material. The material is then stockpiled awaiting shipment.
The design of belt and apron feeders is fairly standardized, and most of the producing companies use pre-defined models and calculation methods to get short delivery times with a low-cost approach. The main features of the apron and belt feeders are:
Although the conveying devices are reasonably well defined and standardized, there is still room for improvement of the overall plant layout and construction, e.g. crushing plant, silo discharge system, train unloading system, etc. One of the most obvious ways to improve the overall design of such systems is to develop a better understanding of the equipment itself. Today, most OEMs want to be involved in the process of seeking the solution rather than only the supply of the equipment. This will enable the market to make use of the expertise of the equipment supplier and, at the same time, use their knowledge base for developing a wider scope, including other aspects such as silo design, hopper design, electrical and hydraulic issues, etc.
Highland Valley copper mine experienced a decline in mill throughput after implementing larger holes for blasting, which resulted in coarser fragmentation and a coarser product from the primary crushers . In the quarry at Vrsi, as drilling geometry decreased from 3.0m4.5m to 2.9m3.0m while other parameters such as borehole sizes were constant, a significant savings of 14% was achieved for the quarry . Due to a mine-to-mill implementation at the Red Dog Mine, the mine achieved savings exceeding $30 million per year . This indicates that, at least in some ores, improved internal fragmentation carries through the crushing and grinding circuits. The mine-to-mill project in the same mine identified further benefit, specifically the marked reduction in SAG feed size and throughput variability . A second but important benefit was the reduced wear in the gyratory crusher, resulting in a significantly longer period between relines. When electronic detonators with very short delay time were applied in the Chuquicamata open pit copper mine, the fragmentation was markedly improved . In the Aitik copper mine a raised specific charge from 0.9 to 1.3kg/m3 gave rise to an increase in the throughput by nearly 7% due to more fines produced and shorter grinding time achieved .
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.
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 . 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.
The LT Series boosts the efficiency of crushing, and features several features an extensive range of track-mounted crushing plants designed for contracting, LT series primary crushing plant followed by a belt conveying system, or with a
the working face as the primary crushing equipment, and the primarily crushed rocks are transported by either a conveyor or a 10-ton dump truck to the secondary crushing plant and the original 50-inch jaw crusher newly designed and
Linwood is currently the largest capacity quarry servicing the Adelaide metropolitan area. In recent years, the region has seen a flurry of large construction projects such as Adelaides Desalination Plant, the citys Northern and Southern Expressways and the Royal Adelaide Hospital. As a consequence of these important projects, the demand for aggregate products has progressively increased, challenging the quarrys production capabilities. In 2013, site management identified the need to upgrade their crushing and screening plant with the latest technology in order to meet this growing demand.
The requirement for new equipment first became evident in the quarrys primary crushing section. The plants 30-year-old primary jaw crusher was struggling to keep up with production demands. The machines reliability and downtime were affecting overall plant performance. Maintenance costs had risen sharply and the availability of spares had become an ongoing problem. After considering the cost of refurbishing the existing crusher, Linwoods management decided that investing in a new machine was their best option. Following a detailed analysis of the quarrys requirements, the team selected Metsos Nordberg C140 jaw crusher.
Quarry Manager, Andy Baker explains the decision: Minimising the need to modify our existing civils was a key prerequisite for the new machine. Essentially we needed a modern like-for-like crusher that would fit into the existing footprint, increase throughput and be easy to maintain Metsos C140 met all these criteria, he said.
Whilst improving throughput and reliability was a priority, Linwoods management also recognised the upgrade as an opportunity to improve site safety. As part of the crusher installation, new walkways and access platforms were designed to improve access to the quarrys primary crushing station.
Once the C140 was installed, the crushers performance and reliability significantly improved product quality and throughput. The new machines ability to deliver more consistent output also immediately reduced the load and wear rates in other key areas of the plant. Where personnel previously needed to constantly monitor the crusher to ensure a consistent product output size, this was now an automated process. Andy comments, Now we can simply program the gap setting and be confident about what product we are going to get. The C140s hydraulic adjustment provides a massive advantage for us in terms of overall efficiency and safety. It eliminates manual adjustments and associated hazards. This saves us time and keeps our production rates up, he said.
The plants primary crusher upgrade represented a big change for quarry staff, as it brought the latest technology to the primary crushing process in the form of advanced automation and safety. Metsos Area Manager - Andy Gough says that post-commissioning support was very important to ensure a smooth transition period. The new machine offered many benefits, however it was a significant change for the site. We worked hard to maintain a presence at the quarry post commissioning, offering a comprehensive range of support services during this critical period, he said
Shortly after the new crusher was installed in 2014, its increased production capacity shifted the sites bottleneck to the tertiary crushing circuit. Tertiary crushing involves further reducing aggregate in size while shaping it into final end products. Whilst its important to keep up with upstream feed rates, high precision is required to ensure the right product shape. Linwood had two cone crushers responsible for this task that were nearing the end of their effective service life.
By weight and volume, cubically shaped aggregate is characteristically much stronger than flatter, elongated material. A problem with the existing crushers was their inability to reliably produce aggregate that met the required index of elongation and flakiness. To get the right shape, operators had to recirculate the output product through the crushers, and/or channel it for additional screening and polishing. Recirculation required additional processing time, which could have been utilised producing new feed material.
Another method employed by the quarrys team to improve shape was to set the crushers with tighter closed-side settings. This increased downstream plant load causing the screens and conveyors to use more energy or become overloaded. Running the crushers longer also increased machine wear, energy consumption and reduced overall production rates. With output quality so heavily dependent on operator intervention, another problem was the constant risk of end-productstock piles being contaminated with inferior product. The combination of these inefficiencies meant there was also less yield per unit of feed.
Site management considered replacing their tertiary cone crushers with units from Borals extensive install base. Eventually, the team decided that the installation of two new machines would provide the best solution. After an exhaustive selection process which took into acount all of the quarrys requirements, in 2015 Metso was awarded with a contract to supply two Nordberg HP3 cone crushers.
When Linwood first compared Metso HP3s specifications with their existing crushers, it was a challenge to reconcile their performance and operating requirements. One of the first things that the team noticed was how different the crushers size, power and capacity were. The HP3s design was physically smaller than the old crushers, yet Metso claimed that the machines had a 20% higher throughput capacity and could produce a higher precision product with one-pass production.
According to Peter Small, Metsos Capital Sales Manager, there are a number of factors that allow the HP3 to outperform similar sized machines. He says that while automation with integrated control is an important factor, it is the efficiency of the crushing process that makes the biggest difference. Peter provides some insight, The HP3s efficiency is derived from a design that increases the concentration of aggregate inside the crusher. It applies more crushing force and relies on a greater degree of inter-particle crushing. Getting these elements to work relies on complex calculations and detailed analysis of process variables, feed material characteristics and final product specification.
Peter says that an essential part of Metsos crushing solution is BRUNO, the companys Crushing and Screening simulation software tool. BRUNO calculates and tests process models based on empirical crushing and screening expertise. Being able to demonstrate the capabilities of alternate configurations and designs gives our customers great confidence in the equipment and the designs we propose, he said.
When Linwood needed to select its new crushers, the HP3 had just been released. There werent any of these machines operating in Australia, which meant Linwoods decision makers couldnt call upon the experiences of their usual references within Boral or the broader quarrying community. The availability of spares for the first and only units in Australia was also a concern.
Linwood recognised that the next generation HP3 offered many benefits. The technology would future proof the sites tertiary circuit and enable the wider integration of automation across the entire plant. Santanu Ghosal, Linwoods Project manager, elaborates, The benefits were clear to us, but choosing the HP3s was still a leap of faith. Ultimately I think it was the confidence and expertise of Metsos people that gave us the assurance we needed. We had access to a very responsive team of local and international experts; and had enjoyed great post-sales support with our C140 primary crusher.
Andy Baker says that Metsos local and global support network was a significant factor in Linwoods decision making process. The support we received helped us to fully explore and understand the options and benefits the HP3s could offer, specific to our situation. For me, a key differentiating factor was the integrated control and automated operation of the HP3s - we knew this was the single biggest technology step towards improving our product quality and efficiency.
Replacing the old crushers with the new HP3s was always going to be a challenge while maintaining aggregate production rates at the quarry. From an electrical point of view, the HP3s larger motor required new mounting and cabling arrangements from the crusher through to the switch room. The mechanical work included installing new cooling units and a bigger standalone lubrication system. A redesign of the feeder to a new location was also required. Alongside this work were the sites safety improvements, which included extended platforms and improved working areas. The team estimated that the electrical and mechanical upgrades would take the tertiary crushing station offline for at least 17 days.
This made the timing of the installation a critical consideration. Linwoods management originally considered performing the installation over Christmas, but were concerned about the availability of personnel, parts, and materials during this period. Whilst management planned to stockpile product in preparation for the installation, at the same time they had major projects to supply and knew their reserves wouldnt last 17 days. In order to help mitigate the loss of production, a trailer mounted cone crusher and screen was refurbished to supplement supply while the main plant was offline.
During the selection process, a high degree of automation was a requirement for the site. Once the new HP3s had been installed, feedback from the quarrys operators has been particularly centered on this aspect. The HP3s touch-screen interface allows operators to have quick and easy access to troubleshooting, throughput and motor current information. Mechanical settings, which previously had to be manually adjusted, are now performed in a matter of seconds via the machines touch screen. The productivity benefits and the elimination of safety risks involved in manual adjustments have made these features very popular with site operational staff.
Stray metallic objects, called tramp iron, that enter the crusher can stall and even damage the machine. The HP3s innovative tramp release system with dual-acting hydraulic cylinders and fixed return point lets the crusher easily eject tramp iron. If the crusher stops under load, the dual-acting hydraulic cylinders provide a powerful stroke that clears the crushing cavity. In both instances the crushers settings are instantaneously restored without the need for operator intervention.
The HP3s liner fastening system doesnt require the backing material that is common with other crushers.When liners are changed or reconfigured, hydraulic motors rotate the bowl completely out of the adjustment ring threads. These two innovations save a lot of time and labour.
The upgrades to Linwoods crushing circuit have improved the sites production capabilities and modernised its crushing process. Commenting on these outcomes, Andy Baker believes the site is now capable of producing more, while maintaining high product quality and improving safety. The throughput we are getting has surpassed our expectations. Our ongoing maintenance costs have come down, while the automation and access platform upgrades have improved plant safety. Overall, we can now more reliably meet market demands for our key-specification products,he said.
Commenting on Linwoods successful application of new crushing technology, Metsos Vice President for Aggregates - Shaun Fanning highlights the importance of the project. We are extremely happy to support Borals long-term growth plans through such an important project for the Linwood site.
We strive to make the big difference by offering quality equipment and supporting our customers with an extensive program of post commissioning services to ensure many years of machine reliability, he said.
The answer might be three if youre referring to stations in a complete crushing plant primary, secondary and tertiary crushers. Of course, there are also different styles of crushers: compression-style jaw and cone crushers, for example, which fit into the various stations within a crushing circuit.
The number of crusher types, in terms of style and configuration, can be more difficult to quantify, as there are many ways to customize crushers. Still, there are four basic designs jaw, cone, gyratory and impact crushers that operate within many crushing plants.
To provide more depth to the question presented at the outset of this article, heres a breakdown of the fundamental details you should know about crushing to ensure your operation has the proper machinery.
Its common to use multiple crusher types within a project and set them up as stations in a circuit format to perform the necessary material reduction work. In many cases, primary, secondary and tertiary stations are established to reduce the rock to the desired size, shape and consistency.
For instance, if the final size of your product only needs to be between 4 in. and 6 in., a primary jaw crusher can accomplish this goal. However, you will likely require a much finer product, and that means incorporating up to three stations, including a variety of crusher types.
Typically, the minimum setting on most primary crushers is about 4 in. to 6 in. Jaw, gyratory and impact crushers are most often appropriate as primary crushers, although there can be overlap between primary and secondary machines.
2. Secondary crushing. Reduction ratios become an important consideration in secondary crushing. Knowing just how fine you need a final output to be, along with the feed requirements of your tertiary crushing station, will help to determine how much reduction needs to take place within this stage.
Cone crushers are often placed within a secondary crushing station because they are versatile in terms of feed and discharge openings. With cone crushers, though, it is essential to operate them at consistent settings to keep productivity up.
Operations can also choose between stationary, modular and portable crushing plants. Stationary plants, like the one pictured, are often selected because they feature higher capacities and lower production costs with easier maintenance. Photo courtesy of Kemper Equipment.
3. Tertiary crushing. The goal of the tertiary, or final, reduction stage is to size and shape rock or other material into marketable products. Again, there may be overlap between stages regarding which crusher styles work best between secondary and final crushing. Cone crushers, vertical shaft impactors (VSIs) or even high-pressure grinding roll crushers canbe used in the tertiary position.
The type of rock you need to process will dictate the types of crushers needed in the crushing circuit. The more you know about the aggregate you wish to crush along with its end use the easier it will be to select the best equipment to achieve project goals.
Jaw crushers are also known as rock breakers and are used to break up larger, harder materials into more manageable pieces. They tend to do well with different types of materials, and they dont display as much wear and tear as impact crushers.
2. Gyratory crushers. These are actually quite similar in concept and design to jaw crushers. Both feature a conical head and concave surface (often lined with manganese steel) and break material apart by compression through what is known as eccentric movement.
3. Cone crushers. Along with jaw crushers, cone crushers are classified as compression-style crushers. These are typically used with more abrasive and harder materials like granite. These types of machines are very powerful and reduce materials by squeezing them until they break apart.
Some operations also use impact-style crushers after theyve already used a different type of crusher that produces a more elongated stone. This helps to further shape the crushed material into a finer consistency with a more cubical nature.
Impact crushers tend to be less expensive than compression crushers and have a higher reduction ratio. They can also break sedimentary deposit-type rocks, like limestone, along natural lines, rounding off sharp angles and weak edges. This produces an end result that is more sand-like in nature.
Dewo machinery can provides complete set of crushing and screening line, including Hydraulic Cone Crusher, Jaw Crusher, Impact Crusher, Vertical Shaft Impact Crusher (Sand Making Machine), fixed and movable rock crushing line, but also provides turnkey project for cement production line, ore beneficiation production line and drying production line. Dewo Machinery can provide high quality products, as well as customized optimized technical proposal and one station after- sales service.
Jan 04, 2019 After the detailed design of this roll crusher, a prototype of the machine was built and extensively field-tested in a six-month campaign at a hard rock quarry in Germany. The crusher model ERC 25-25 selected for this purpose has a crushing roll of 2500mm in diameter and width. The feed opening to the crushing chamber is 2500mm wide and 1230mm ...
Device layout of quarry crushing production line. When the Mohs Hardness of raw material is less than 320Mpa, such as silica and basalt, the main equipment include: vibrating feeder-jaw crusher (primary crushing equipment)-stone crusher (impact crusher, hammer crusher)-vibrating screen-finished stone. The material is transmitted by belt conveyor.
Sep 13, 2017 Time Lapse Camera on the Construction of our Primary Crushing Plant. Video Duration: 1 minViews: 269Author: CarolinaSunrockLokotrack LT series Primary crushing plants for quarrying and ... www.garriockcrushers.co.uk/.../1127/primary_lts.pdfLokotrack LT140 primary jaw plant and ST620 mobile screen in northern Norway. Features and BeneFits Lokotrack Series mobile crushing plants for primary crushing are built around the prov-en jaw and impact crusher concepts. Since the 1920s, Metso has installed over 10,000 jaw crushers and over 1,000 impact crushers worldwide. Full mobility - less
Quarry Crusher Plant Input Size. The input size is the size of feeding materials a quarry crusher plant can accept. There are mainly three crushing stages in a whole quarry crushing production line including primary crushing, secondary crushing and tertiary crushing operation.
Quarry process is a stone crusher plant which crushes the large rock to small gravel and sand materials. What quarry equipment does this process require? From the quarry stone production purposes, the first need for a coarse crusher, which mine down the size of the stones for primary crushing.
These crushers offer an ideal solution for primary crushing applications involving hard, abrasive materials such as granite or recycled concrete. Efficient and less costly to operate because of their minimal moving parts, jaw crushers are well suited to applications where the primary objective is to reduce raw feed material to a manageable size ...
Quarry Mine Crusher Plant for Sale Quarry crushing is generally operated in three stages according to stone properties and final products applications. The complete quarry and mine crushing production line may involves primary crushing, secondary crushing and tertiary crushing plant, screening machine, belt conveyor etc.
The 5165LP can also be used in the primary crushing of medium aggregate and sand and gravel applications. Get Price; Mobile Crushing Station Mobile Crusher Plant Portable . The mobile crushing plant is composed of primary crushing and screening station and secondary one belt conveyor etc.
Dewo machinery can provides complete set of crushing and screening line, including Hydraulic Cone Crusher, Jaw Crusher, Impact Crusher, Vertical Shaft Impact Crusher (Sand Making Machine), fixed and movable rock crushing line, but also provides turnkey project for cement production line, ore beneficiation production line and drying production line.
Conglomerate is a kind of rock whose particle debris content is more than 30%. At the same time, the diameter of particle debris is larger than 2 mm. Conglomerates main constituent is lithic debris, only a small amount of mineral debris. And the interstitial materials are sand, silt, clay and chemical substances sediment. The hardness of conglomerate is 7, the proportion is 2.65.The colors are always milky white, yellow, brown, and gray. Conglomerate has a higher fire resistance. According to the size of gravel, conglomerate can be divided into boulder conglomerate (> 256 mm), large conglomerate (64 to 256 mm), pebbles conglomerate (4 to 64 mm) and fine conglomerate (2 to 4 mm). Depending on the complexity of gravel ingredients, conglomerate can be divided into single-component conglomerate and complex-component conglomerate.
At first, we need to choose a primary crusher. Jaw crusher is always the necessary equipment in various minerals processing line.It is with the features of large capacity, high reliability, easy maintenance and low operating cost. So it is widely applied in coarse crushing of a variety of high hardness materials and low hardness materials.
After primary crushing, we need a cone crusher for secondary crushing. You have many different choices, such as CS Cone Crusher, HCS Cone Crusher, HPC Cone Crusher, and PY Cone Crusher. All of them are designed by our professional engineers. Our cone crushers absorb advanced technology around the world, and adopt high-tech materials. At last, VSI5X Crusher is necessary crushing equipment used in manufactured sand production line, sand and gravel production plant. It adopts hydraulic opening device, which making this crusher is convenient to maintain, time saving, and labor saving. Throughout optimization and upgrading, VSI5X Crushers consumption of wear parts reduced more than 30%.
Besides, some auxiliary equipment is essential, such as vibrating feeder, vibrating screen and belt conveyor. Vibrating feeder is used to feed the materials to the specified machine evenly and continuously. Vibrating screen can separate materials into different sizes. The materials with required size can be sent to windrow as final product directly. In this way, it will greatly avoid unnecessary fragmentation process and increase the production. Belt conveyor is the bridge between the neighboring machines. And it can greatly improve the degree of automation and reduce labor costs.
I have introduced a lot about the conglomerate crushing processing line before, now I will tell you the use of conglomerate. After processed, conglomerate can be used for paving.Currently the length of conglomerate road is longer than the total ofconcrete road and asphalt road around the world. Fine conglomerate is an important material for the production of concrete.In addition, it has many important industrial applications.It is the main raw material of glass, refractory, ceramic, foundry, military, communications and other industries.
As a professional mining equipment manufacturer, we can provide all kinds of conglomerate crushing equipment for our customers. And our experienced engineers can design a complete conglomerate processing line according to customers requirements. Owing to high quality products and thoughtful service, SBM stands out among a number of mining equipment manufacturers and wins a broad market. Our machinery has exported to more than 120 countries over the world. If you have any question, please contact us. SBM is your best choice.
The quarrying operation cuts a block of stone free from the bedrock mass by first separating the block on all four vertical sides, and then undercutting or breaking the block away from the bedrock. If the block is large, it is called a quarry block and will be cut into smaller blocks at the quarry. If the block is small enough to be moved from the quarry it is called a mill block and may be sold as it is or taken to a mill for further processing.
Rock commonly has two, and sometimes three, natural directions of cleavage, which influence both quarrying and rock dressing methods. The direction of easiest cleavage is called the rift, the second easiest is the grain, and the third and most difficult, if present, is the head grain or run. If there is no head grain, the third rectangular direction is called the hardway. Modern technology and quarrying methods are less dependent on cleavage than were earlier methods.
Two of the oldest methods for quarrying are channel cutting and drilling and broaching. A channeling machine cuts a channel in the rock using multiple chisel-edged cutting bars that cut with a chopping action. In drilling and broaching, a drilling tool first drills numerous holes in an aligned pattern. The broaching tool then chisels and chops the web between the drill holes, freeing the block. Both channel cutting and drilling and broaching are slow, and the cutting tool requires frequent sharpening. Both methods have generally been replaced with other more efficient methods.
Line drilling or slot drilling is a more modern technique for quarrying, which consists of drilling a series of overlapping holes. The drill is mounted on a quarry bar or frame that aligns the holes and holds the drill in position.
Flame cutting or jet channeling is a common method for cutting granite. Flame from a torch is passed over the rock and the intense heat creates a thermal shock, which causes the rock to spall. This technique does not work in quartz-free rocks, or carbonate rocks that fuse or calcine. Jet channeling creates a wide irregular kerf, which wastes rock; it is also very loud, which is a potential health hazard to workers. Channels can also be cut into rocks using a water jet. A high-pressure pulsating jet of water is directed at the rock, which causes it to disintegrate.
A variety of saws can be used to excavate dimension stone, including wire saws, belt saws, and chain saws. The introduction of synthetic diamond tools during the 1960s revolutionized stone working. Chain saws or belt saws with diamond-set teeth are used to cut softer stones such as marble, sandstone, and slate. Wire saws with diamond-impregnated beads mounted on a wire cable can cut harder stones like granite.
The quarrying industry is a long established but unpredictable industry, involving hazardous conditions for both plant and personnel. Frequently machinery operates under impact loading conditions with charges that vary in weight from only a few kilograms to several tonnes. Much of the machinery is of traditional design, which has evolved over the years. Such designs are not easily codified, nor their rationale documented, and successful performance relies upon step-by-step progress, and operating conditions within historic experience. Quarrying equipment is very heavy duty and is often thought of as low-tech, especially compared with industries like nuclear and aerospace, but the safety and operational reliability of the industry is still dependent on the same features as in these high-tech industries. In addition, practices which have developed over the years may not be the best available, and because of changes in materials and duty may even become inadequate. This chapter presents the study of a failed rock crusher, and shows where design, material selection, and construction aspects can be improved to facilitate more reliable performance.
The crusher in question was used to crush large boulders of limestone, on site, which had been explosively excavated from the quarry face and had not been otherwise reduced in size. It was of a design that has served the industry satisfactorily for several decades. The one which failed was new, however, and had been operating for only 45 months, well short of the usual lifetime for such equipment.
It is normal for rock crushers of this type to have developed a small amount of cracking on the visible faces of the outer disks of the rotors. This cracking may be repaired from time to time, by welding, and under these circumstances the crushers seem to operate indefinitely. The failure described here involved an unusual mode of cracking which was much more extensive, and which had become so within a short operating period.
The manufacturer's initial thoughts were that the crusher had failed by brittle fracture due to a single excessive load, possibly from a non-friable article, which would tend to overload it. However, there was no independent evidence of this. The study also looked at the possible mechanisms for overloading the crusher, and concluded that this was not possible. Other evidence showed that the material could crack by fatigue by an unusual and highly damaging mechanism, and that this was the most likely reason for the failure.
Many lessons may be drawn from the investigation and could be applied to subsequent plants during manufacture and operation without significantly increasing the manufacturing or running costs, and these were incorporated into a replacement crusher. These succeeded in preventing a recurrence of the mode of cracking that led to failure, but not in eliminating the more common form of cracking. It was thought possible that this mode of cracking was self-arresting, and hence benign. If this could be shown to be the case by analysis, the weld repairs would then become unnecessary and the associated loss of availability and other expense could be avoided. However, the operators declined to support the necessary analytical work, so this avenue could not be investigated. No reason for this rejection was given, but a reluctance to change practices, even when established ones can be shown to be of no benefit, is a common feature in industries which do not have a tradition of applying specialist expertise.
Plans for quarrying must include all operational aspects of mining, including overburden and mineral handling, storage, haul road placement, volumes involved, equipment selection, reclamation and economics. Consideration must be given to annual production; physical, environmental and permitting restrictions (limits of mining, ultimate depth, etc.); desired benching configuration; location of the groundwater table and other impacting factors.
The importance of all these factors being designed appropriately goes beyond the boundary of the quarry and the cost of production. For example, inaccurate calculation of the size of machinery required can easily lead to benches being worked in the order that the material is most easily won rather than the optimum for consistent quality of raw material.
Once material is removed from the quarry face it begins its journey to the raw plant and then to the factory and the customer. If an adequate block model is in place and the composition of each block of material is known before it is despatched from the face, then all the tasks further down the line will be easier than if the material is of unknown composition until the raw meal for the cement kiln has been made.
Historically, quarrying was very much a local task. This fed the development of the vernacular, local distinctiveness, certainly before transportation became widespread and economical. Local sourcing of stone markedly influences its sustainability credentials, with transportation within the United Kingdom accounting for around 1020% of the EC (comparing Cradle-to-gate (C-G) and Cradle-to-site (C-S)). Importation increases the carbon footprint many times over (Crishna et al., 2010). Local sourcing supports employment, often rural. Energy sources associated with extraction and processing include fuel for plant, modest use of explosives, and electricity and water for processing.
The extraction and processing of dimension stone is fairly consistent in terms of process across the United Kingdom. Extraction processes vary according to the type and characteristics of the stone; however, in the main, the aim is to secure the largest bulk block size within practical constraints. These blocks are then inspected to appraise the most efficient way of cutting into slab form with minimum wastage (Stark, 2005). Typically the stone is seasoned in the yard to harden up, although it may be processed green. Cutting is by plant machinery, the primary cut being to reduce the rough bulk to slab forms, and the secondary cut(s) to dimension stone sizes. Tooling, dressing and other finishing is then undertaken according to the final product required.
Approximately one-third of the rock deposit is estimated to become the primary product of dimension stone, the rest of which comprises overburden or primary waste, which then becomes available for by-product usage (Siegesmund and Trk, 2011). This general approximation is of course dependent on the type of stone being quarried, and the product required.
Once commissioned, even the best-planned industrial development requires monitoring and management to ensure that its operation continues to be environmentally acceptable. This applies equally to established industries. When unexpected environmental problems develop, a rapid response is required to assess the cause and magnitude of the problem and to devise remedial measures.
Dusts produced by quarrying and fluorides emanating from oil refineries are typical pollutants, which need regular monitoring. A range of portable equipment for the identification and quantification of toxic and other gases can be used on an ad hoc basis.
When unpleasant odors resulting from manufacturing processes or waste-disposal operations give rise to public complaints they should be identified and quantified prior to deriving methods of abatement. Such work is often innovative, requiring the design and fabrication of new equipment for the sampling and analysis of pollutants.
Consultants are equipped to monitor the quality of freshwater, estuarine and marine environments and can make field measurements of a variety of waterquality parameters in response to pollution incidents. For example, reasons for the mortality of marine shellfish and farmed freshwater fish have been determined using portable water-analysis equipment. Various items of field equipment are, of course, also employed in baseline studies and monitoring, respectively, before and after the introduction of new effluent-disposal schemes.
Where extreme accuracy is required in the identification of pollutants or in the quantification of compounds that are highly toxic, laboratory analysis of samples is conducted. Highly sophisticated techniques have, for example, been employed in the isolation of taints in drinking-water supplies.
As development proceeds, land is coming under increasing pressure as a resource, not only for the production of food and the construction of new buildings but also for disposal of the growing volume of industrial and domestic waste. The design and management of sanitary landfill and other waste-disposal operations requires an input from most of the environmental sciences, including geologists and geo-technicians, chemists and physicists, biologists and ecologists. Such a team can deal with the control and treatment of leachate, the quantification and control of gas generation, and the placement of toxic and hazardous wastes. This may be needed in designs for the treatment of industrially contaminated land prior to its redevelopment.
The acceptability of some industrial and ephemeral development projects such as landfill or mineral extraction may depend upon an ability to restore the landscape after exploitation has been completed. As more rural development projects come to fruition, ecologists will become increasingly involved in resource management to ensure that yields are sustained and to avert the undesirable consequences of development. Some industrial developments and rearranged plant layout schemes will not be complicated, but when ecology studies are needed, the employment of specialist consultants is recommended.
The sample was sourced from Gosford Quarrying, which is located at 300 Johnston St, Annandale, Sydney. Due to the size and weight limitations, the most suitable sample was chosen and transported to Rock Mechanics Laboratory. A specification sheet was obtained from the Gosford Quarrying store, which gives a general idea of the characteristics of the sample. The sandstone is in a brown and banded color, and primarily names as Mount White Brown. Its geological name is Argillaceous Quartz Sandstone, which is formed in the Triassic age. Based on the specification sheet, the sample is described as medium-grained quartz sandstone with a predominantly argillaceous matrix. The concentration and distribution of iron oxides influence the nature of the color banding and density of color. The bulk density of this sandstone is approximately 2.27t/m3 with 4.4% of absorption. The modulus of rupture is 8.9MPa in dry condition and 2.5MPa when is wet. The compressive strength is around 37MPa (dry) and 22MPa (wet).
A diamond wire has become a standard stone quarrying tool which enables high production rates and increased output of blocks that are used for monumental purposes in areas where flawed or fragile stone is quarried. Owing to its adaptability to suit most sawing tasks, it has also made rapid progress in stoneyards, where both single-wire and multi-wire stationary machines are increasingly used for block division (Fig.19.16), as well as for profiling of stone slabs. A typical wire saw contains 1011mm diameter diamond impregnated beads mounted at regular intervals on a flexible 5mm diameter steel rope composed of many twisted together high strength stainless steel strands. The multi-wire machines utilise 68mm beads on a 4mm steel rope to minimise kerf widths and thus to maximise the yield of stone slabs per block.
The cutting action consists of pulling a properly pre-tensioned wire saw across the workpiece. The linear wire speeds and cutting rates achieved on stationary machines are similar to those applied in the quarry and depend on the stone type as shown in Table19.5.
The versatility and economic advantages of the wire saw technology have also been recognised in the construction industry, where portable wire saw machines are used for various construction, renovation and controlled demolition purposes. The ability of the diamond impregnated wire to cut cleanly, quickly and accurately, with little noise and vibration, makes this tool an ideal alternative to blasting or jack hammering with flame cutting of the rebar, which were previously used for removal of thick sections of reinforced concrete or brickwork. The cutting rates achievable on construction materials may widely vary from 16m2h1 on reinforced concrete, through 511m2h1 on plain concrete, up to 1018m2h1 on masonry, depending on the type of concrete aggregates, percentage of steel reinforcing, brick composition, and so on.
It is essential for the tool performance that the diamond beads wear in a uniform manner over the whole working surface. In industrial practice, pre-twisting the wire, by applying one anti-clockwise twist per metre before a continuous loop is assembled, gives rise to its rotation in the kerf and consequently prevents bead ovalisation.
Concrete construction is marked by activities related to the quarrying and processing of raw materials, which consist largely of NA. NA are nonrenewable as their geological processes of formation take a long time (millions of years) and their continuous and increased consumption decreases their reserves. Currently, high-grade reserves of the earths NA have been exploited in construction activities to a point where the availability of NA is now scarce, if not practically unrealizable in some regions or countries, particularly in urban areas. As a result, materials are transported for long distances, and this in turn elevates the energy consumed and construction project costs, both leading to a number of environmental problems such as greenhouse gas (GHG) emissions and resource depletion. Environmental concerns over the excessive mining of NA compared to other aggregate types, such as recycled aggregates, can be addressed by changing raw material consumption patterns in concrete construction through dematerialization.
The application of dematerialization in concrete construction can be partially achieved through the use of recycled concrete aggregates and through the structural optimization of a structural component to reduce the volume of materials used, which in turn leads to a reduction in pollution generation.
Mining is the process of extracting buried material below the earth surface. Quarrying refers to extracting materials directly from the surface. In mining and quarrying, water is used and gets polluted in a range of activities, including mineral processing, dust suppression, and slurry transport. In addition, water is subtracted from the environment in the process of dewatering, the process of pumping away the water that naturally flows into the pit or tunnels of the mine. When disposed, this water may also carry pollutants. The mining and quarrying sector includes mining of fossil fuels (coal and lignite mining, oil and gas extraction), mining of metal ores, quarrying of stone, sand, and clay, and mining of phosphate and other minerals. A rich data source of water use in the mining of conventional and unconventional oil and gas, coal, and uranium is provided in the work of Williams and Simmons (2013).
Mudd (2008) provides a useful review of gross blue water use in different types of mining (Table 7.3). In general, he found that the higher the ore throughput, the more likely that, through economies of scale, the unit water use per kilogram of ore is lower. Furthermore, he found that as metallic ore grades decline, there is a strong probability of an increase in water use per unit of metal. Gold has the highest water use per kilogram of metal, with platinum closely behind; this is presumably attributable to the very low grade of gold and platinum ores (i.e., parts per million compared with percent for base metals). It is noted here that net blue water use, the blue WF, will be substantially lower than the figures presented in Table 7.3, because most of the water will remain within the catchment.
Pea and Huijbregts (2014) made a detailed estimate of the operational and supply chain blue WF for the extraction, production, and transport to the nearest seaport of high-grade copper refined from two types of copper orecopper sulfide ore and copper oxide orein the Atacama Desert of northern Chile, one of the driest places on earth. The total blue WF (direct and upstream consumption) for the sulfide ore refining process was 96L/kg of copper cathode. The first step in the process, the extraction from the open pit mine, accounts for 5% of the total blue WF; the second step, comminution (crushing, grinding), accounts for 3%; the third step, the concentrator plant, accounts for 59%; the fourth step, the smelting plant, contributes 10%; and the last two steps, electrorefinery and the sulfuric acid plant, contribute 3% and 1%. The supply chain contributes 19%: approximately 9% related to materials and 10% related to electricity. In the case of the copper oxide ore-refining process, the blue WF was 40L/kg of copper cathode. The first step, extraction, accounts for 2%; the second step, comminution and agglomeration, contributes 18%; the third step, the heap leaching process, accounts for 44%; the fourth step, solvent extraction, contributes nothing; and the last step, electrowinning, accounts for 10%. The supply chain contributes 26%: approximately 6% related to materials and 20% related to electricity.
Generally, mining has a significant gray WF, but it is difficult to obtain quantitative data for this. The first source of pollution can come from the overburden, the waste soil and rock that has to be removed before the ore deposit can be reached and that has to be stored somewhere after removal. The strip ratio, the ratio of the quantity of overburden to the quantity of mineral ore extracted, can be much higher than one. The overburden material, sometimes containing significant levels of toxic substances, is usually deposited on-site in piles on the surface or as backfill in open pits, or within underground mines (ELAW, 2010). Through erosion, runoff, and seepage, these toxic substances may reach groundwater or surface water bodies. The second source of pollution comes from the pit itself, where similar processes may spread toxic chemicals into the wider environment. In addition, mine dewatering can bring polluted water from the mine to the streams into which the water is released. The third source of pollution comes from the waste material that remains after concentration of the valuable mineral from the extracted ore and that often contains various toxic substances (like cadmium, lead, and arsenic). This waste, the so-called tailings, is generally stored in tailings ponds, which may leak. Also, there are numerous incidents of tailings reservoir dam breaks, after which the content of the reservoir released itself into the environment. A fourth source of pollution can come from the process of heap leaching. With leaching, finely ground ore is deposited in a large pile (called a leach pile) on top of an impermeable pad, and a solution containing cyanide is sprayed on top of the pile. The cyanide solution dissolves the desired metals and the pregnant solution containing the metal is collected from the bottom of the pile using a system of pipes, a procedure that brings significant environmental risk (ELAW, 2010). Finally, a form of mining that typically results in significant water pollution is the so-called placer mining, in which bulldozers, dredges, or hydraulic jets of water are used to extract the ore from a stream bed or flood plain (ELAW, 2010). Placer mining is a common method to obtain gold from river sediments.
Once the overburden has been removed by processes similar to those used in hard rock quarrying, deposits of sand and gravel are usually extracted by a range of earth-moving plant (Figure 16.6). Some sand and gravel pits extract beneath the local water table and are wet pits, whereas others exploit wholly above the water and are dry pits. Various types of dredger are commonly used for extraction in wet pits, or occasionally large excavators. In dry pits, a great variety of diggers or scrapers may be used, or very occasionally strong water jets known as monitors. In the case of some deposits, wet pit working has the advantage that very fine or clay material can be washed out during the winning and the subsequent transportation of the material to the processing plant.
Fig. 16.6. General view of a sand and gravel pit in Essex, UK. The boulder clay overburden has been removed, the sand and gravel deposit is being worked using earth-moving plant and the base of the sand and gravel rests on London Clay.Get in Touch with Mechanic