Ideal for producers and contractors in mining, aggregates, crushed stone production and recycling applications, the T400 portable cone crusher plant offers quick, safe maintenance access, consistent crushing and easy mobility as the result of direct customer feedback.
The T400 cone is part of the T-Series Cone Crushers line by Telsmith that offers large clearing circuits that are designed to safely and quickly allow uncrushable materials to pass, avoiding costly damage and associated downtime for repairs. The patented anti-spin feature prevents head spin to help extend manganese service life. Like other key components, it's mounted on top of the machine for safe, top-service access.
In addition, the anti-spin operates with pressure lubrication oil, eliminating the need for a gearbox, separate hydraulic circuit and associated maintenance. The use of a single bowl for all liners over its life of operation helps reduce downtime and inventory costs while allowing optimum versatility, flexibility and efficiency in portable crushing applications.
Furthermore, Telsmith Inc. patented hybrid bearing technology within T-Series Cone Crushers provides the ability to crush at lower horsepower from improved lift that helps carry the crushing forces, when compared to roller bearing machines. Engineered to hold up to tough, abrasive aggregate and mining processes, the T-Series cones with hybrid bearings deliver tested productivity, safety and ease of maintenance with maximum uptime.
The T400 cone crusher performance is second to none by supplying 400 horsepower, a 12-in. maximum feed size and throughput capacities ranging from 138 up to 594 mtph allowing for consistent crushing and sizing of materials.
Startup is made simple allowing for operations to begin the crusher within hours. To achieve this, Telsmith designed three simple user-friendly control panels, Soft Start, Motor Start and Off-Plant. The Soft Start UL certified NEMA4 panel consists of a main circuit breaker for the crusher motor soft start. The Motor Starter UL certified NEMA4 panel provides a main circuit breaker, motor starters for plant motors and 4 extra 20HP motor starters for off-plant conveyors. The Off-Plant Panel support stand provides cord grips and 50' wiring from starter panels to on-plant junction box.
TRAC10 monitors crusher operations, provides automated calibration and setting controls, and protects the crusher from overload; all to yield greater crushing performance and efficiency. Operators can initiate an automated calibration process via the touch screen monitor, that automatically "zero's-out" and resets to the proper setting. Operators can also modify the crusher setting at any time, even while crushing.
Telsmith engineered and manufactured chassis provide ease of mobility and strength to handle the vibrations of many crushing applications. The T400 portable chassis offers 24 in.x 68 in. WF Main beams, fifth wheel plate, equipment supports and cribbing legs that are easily adjusted for quick setup and mobilization.
Telsmith offers chassis compliant with all 50 states on-highway regulations. The T400 standard chassis includes triple axles and highway towing kit with 25,000# axles, air brakes, walking beam axle support, (12) 11R22.5 tires, mud flaps and lights with reflectors. Total transport weight and dimensions for the standard configuration are 100,000 lbs. and 50 ft. 9 in. L x 11 ft. 11 in. W x 13 ft. 6 in. H.
MEKAs cone crusher is a very good example of our determination to gain customer trust in the field of crushing and screening equipment. The solid structure required for crushing very hard materials allows the operators to employ the cone crusher for a wide range of applications, crushing everything from limestone to basalt. In addition, its versatility enables our customers to keep a high profit level in changing conditions. The cone crushers optimised speed and improved crushing chamber design provides high productivity with less wear on parts, meaning a great savings in labour. The adjustable crushing chamber can provide the required size of material, and is able to meet a variety of customer needs.
Today, technology is a part of every aspect of life, and our businesses are no exception. MEKA aims to satisfy our customers needs completely because we know that client profitability pays dividends in higher trust and better customer relationships. MEKA cone crushers arrive to our customers complete with the automation system as standard, without any extra charge.
Our automation system maintains closed side settings in a stable position by tracking wear part abrasion. This creates a significant increase in crushing efficiency and also enables the use of wear parts for longer, with more profitability. In addition, it makes scheduling wear part replacement easier than ever. The automatic control system can adapt the closed side settings in accordance with different feed conditions and keep the system in choke feed, creating more rock-on-rock crushing action and increasing profitability.
Automation helps to increase the security of the crusher in case non-crushable material, such as a piece of metal, enters into the crusher cavity and causes high pressure. The relief valve is opened automatically, releasing hydraulic oil from the cylinders to prevent the machine from being severely damaged.
With over 100 years of experience and our knowledge of crushers and different minerals processes, we know how crusher wear parts fit and function within a crusher to provide maximum performance. Our cone crusher wear parts are designed to the same specifications and standards as our cone crusher equipment, ensuring equipment compatibility for reliable and safe operation.
We have complete control over quality at every step of the process, from the selection of raw materials to final production. Metso Outotec cone crusher wear parts are made of high-quality manganese in a continuously monitored process at our own foundries and manufacturing facilities.
Our selection of cone crusher wear parts ensures that there is a solution for your application. We have the expertise to select both the chamber and the material to fit your crushing process. The right wear profile improves crusher performance and extends wear life, leading to less downtime and fewer liner replacements, which in turn increases safety and reduces the cost per ton. Our cone crusher wear parts are available for all Metso Outotec crushing equipment, but we also offer crusher wears for non-Metso Outotec crusher models.
Our premium cone crusher wears are designed to provide extended life, lower cost per ton, and optimized capacity and performance even in the most challenging conditions. Our selection of premium cone crusher wear parts has solutions for every type of application. We also have the expertise and tools to offer customized solutions and chamber optimization services to find the optimal crusher wear parts that will bring your specific crushing application improved crushing performance and lower cost per ton.
Get the maximum potential out of your size reduction process to achieve improved crushing performance and lower cost per ton. By using our unique simulation software, our chamber optimization experts can design an optimized crushing chamber that matches the exact conditions you are operating under.
Maintain control of your daily operation at an affordable cost with Metso Outotec O-Series crusher wear parts. We offer O-Series crusher wear parts for Nordberg HP, GP and Symons crushers. These O-Series crusher wear parts are designed by original equipment manufacturer (OEM), so you can trust that they fit and function with your Metso Outotec crusher.
With multiple fabrication options and upgrades to choose from, Metso Outotec's cone crusher spare parts are eliminating the risk that the replaced part becomes the weak point in your crusher. They offer stable production without unexpected downtime.
Contender Series spare and wear parts are designed to fit and perform with Sandvik CH, CS and CJ crushers. The premium spare parts are designed using our OEM know-how. Selected spare parts are enhanced with better safety, easier maintenance and longer life. Wear parts are designed to meet OEM standards, going well together with Contender Series spare parts. Wear parts for CH430 and CH440 crushers are further complemented with lifting tools.
The last time that E&MJ looked at crushing technology (November 2010, pp.38-42), the focus was predominantly on primary crushers and mobile units. Here, we turn the spotlight on cone crushers, used more often for secondary and tertiary crushing duties in both the mining and aggregates industries.
Industry consolidation over the past 20 years has resulted in a much smaller pool of suppliers servicing the market, althoughas in the construction sectorChinese equipment manufacturers are becoming increasingly international in their marketing approach. While Chinese-supplied crushers may well find their way into projects in which there is a significant Chinese funding contribution, for the established sector the choice stands between machines from four major manufacturers: Finlands Metso Minerals, Sandvik Mining & Construction from Sweden, the U.S. arm of Denmark-based FLSmidth, and Telsmith, also from the U.S.
Recent Addition to the Raptor Range Last year, FLSmidth introduced a new top model to its Raptor cone-crusher range, the XL2000. With effectively double the capacity of the previous top-of-the-range XL1100, the XL2000 cone is powered by a 2,000-hp (1,750-kW) motor, making it ideal for high-tonnage mining operations, the company states.
FLSmidth adds that its new machine provides opportunities for linking cone crushers directly to a primary crusher, offering the capability of producing up to 10,000 t/h of minus 125-mm material when a primary gyratory is followed by XL2000 cone crushers. The advantage of producing a finer product and higher total tonnage from a primary gyratory and XL2000 is that fewer screens and crushers will be required in later stages to prepare material for milling or leaching. Because of this, the XL2000 cone crusher provides a better return on investment for high-tonnage applications, FLSmidth said.
Innovations introduced on the XL2000 include double-acting tramp-release and clearing cylinders, and easy access to critical load-carrying bearings. The machine also has a sleeved main shaft to allow for rapid disassembly and access to all bronze bearings/bushings for inspection or replacement, and an improved seal design to help reduce failures caused by material ingress.
FLSmidth can supply its Raptor cone crushers with input power ratings from 300 to 2,000 hp, suitable for installing in both mobile and stationary applications. The three largest machines in the range, the XL900, XL1100 and XL2000, are the most likely to appeal to the mining sector. With a 1.8 m (71 in.) crushing head, the XL900 can take feed material up to 14.57 in. (313 mm) with a maximum throughput of nearly 1,400 t/h (1,270 mt/h). The XL1100, meanwhile, is capable of taking minus-24 in. (620 mm) feed.
Two recent equipment-supply orders announced by the company have included cone crushers within the machines being provided. In November, the award of a $30-million contract by the Indian state company NMDC Ltd., included a cone crusher in the equipment being sourced for its Kumaraswamy iron ore project. This order followed one earlier in the year from Mineral Lumina Copper for its Caserones copper-moly project in Chile, where FLSmidth cone crushers will form an integral part of the 105,000 mt/d processing circuit.
Wear Monitoring Helps Maintenance An Astec Group member company, U.S.-based Telsmith reports that its SBS and SBX cone crushers offer state-of-the-art technology that has evolved from more than 100 years of experience. Standard features include hydraulic overload protection, chamber clearing and pushbutton adjustment control with digital setting display, while options include a no-maintenance, hydraulic anti-spin system that reduces manganese wear costs, and the companys TRAC10 automated crusher-control system that, it claims, improves efficiency and reduces operating costs.
The companys current cone-crusher portfolio includes five SBS models, with power requirements ranging from 200 to 600 hp, and three SBX models (300, 400 and 500 hp). SBS cone crushers can handle both coarse and fine crushing from secondary to fourth-stage applications, while the SBX models are designed for extra-coarse secondary crushing. The SBX machines can also accept larger feed, fitting into secondary crushing circuits that once required larger, more expensive machines, Telsmith notes.
Telsmith cone crushers feature a cam-and-lever crushing action, allowing them to work with many different liner profiles. The company states that in most installations, an anti-spin system will deliver longer liner life, and claims its hydraulic anti-spin design is the most advanced available. A small, low-maintenance hydraulic motor, coupled to the main shaft, allows the head to spin only in the crushing direction, while the system can interface with automation systems to provide greater crusher protection and automatic setting calibration.
Its crushers also feature an advanced clearance system that can be used in the event of a power failure or when tramp metal enters the crusher. The push-button system works by lifting the upper frame vertically, allowing material in the chamber to fall through the crusher quickly and safely, giving the minimum of downtime.
Optimum crusher settings are maintained via remote adjustment, with the crusher operator able to initiate an automated calibration process via a touch-screen monitor. The operator can also modify the crusher setting at any time, even while crushing, with the system providing warnings when liner wear reaches various set levels between 50% and 100%.
Sensors continuously monitor crusher lube, hydraulic and electrical systems, making adjustments and providing advanced warnings, with historical records and trending data providing additional tools that can be used for predictive maintenance.
Multiple Choices of Liners and Throw Sandvik reports that its mining cone crushers are of advanced design with a small footprint and high capacity in relation to their size. They have a high reduction efficiency and high capacity in round-the-clock mining operations. Major features include hydraulically adjusted closed-side setting (CCS), Sandviks Automatic Setting Regulation (ASRi) system, and a choice of several different crushing chambers.
The companys CS and CH series of cone crushers have a wide field of use, as they can easily be matched to changes in production through the proper selection of the crushing chamber and eccentric throw. Its cone crushers are designed for secondary, tertiary and pebble crushing, while their easy-to-install and easy-to-service design allow them to be used in replacement, expansion or greenfield projects.
With Sandviks Constant Liner Performance (CLP) design, the almost vertical profile of the feed opening area means the shape of the crusher chamber remains virtually unchanged throughout the wearing life. In combination with CLP crushing chambers, high motor powers give its crushers capacities that are in most cases comparable with those of other, larger crushers. It cites advantages of CLP as being constant feed acceptance capability; increased output; and increased liner life, leading to lowest total cost.
Sandvik offers four models in its CS range, and six in the CH series, with the largest of these, the CH880, taking an 800-hp (600-kW) motor and capable of handling up to 2,130 mt/h. Its feed size capabilities range between 75 and 370 mm (2.914.6 in.), with a CCS range of 870 mm (0.32.8 in.). Two newly designed models, the CH890 and CH895, will supersede the CH880, with both new machines designed to increase operational performance in both secondary, tertiery and pebble crushing. They will have increased power (1,000 hp) and significantly increased crushing force, Sandvik says.
Last year, Sandvik delivered eight cone crushers to the Russian iron ore producer, Stoilensky GOK, as part of a program aimed at upgrading its secondary and tertiary crushing plant. These units followed four CH880s that were supplied in 2006machines Sandvik says led to a considerable increase in productivity.
In Australia, meanwhile, 12 CH880 cone crushers are currently being installed for the major Sino Iron project in the Pilbara region of Western Australia. These will function as pebble crushers, and are being installed in pairs to serve six mill circuits.
Maximum Power, High Performance Metso offers three ranges of its Nordberg cone crushers, the GP, HP and MP series. The company notes the GP concept allows big feed openings with a fairly small cone diameter, adding this is especially important in secondary applications since it means the primary crusher can be opened wider, giving the possibility of higher throughput. GP machines are usually equipped with the Nordberg IC50 automation unit which, Metso says, guarantees constant choke feeding, improves the liner utilization rate, and enhances end-product quality by promoting inter-particle crushing.
Most GP cone crushers are equipped with a patented piston design, which gives a lower installation height and, in turn, helps cut installation costs as well as making the machine suitable for mobile crusher applications.
Typical applications for Nordberg MP cone crushers include secondary and tertiary crushing for feeding grinding circuits and leach pads, Metso says. With MP designating maximum power, Metso claims the two models in the series, the MP800 and MP1000, can process more ore to the same reduction, or the same amount to a finer reduction than any competing machine. Features include a rotating bowl to give even liner wear, automatic tramp release and a large feed opening, with the units designed to fit onto a 7-ft (2.1-m) Symons crusher foundation.
The most recent additions to Metsos HP series, the HP4 and HP5, build on the companys previous six-model range. With HP standing for high performance, these units give the operator the option of producing much finer products with fewer crushing stages, Metso says, thus lowering investment costs and saving energy. A combination of optimized speed and large throw gives these machines the highest reduction ratios of any current cone crusher, the company claims, a result of their power utilization measured on a cone-diameter basis.
Capable of handling materials as diverse as limestone and taconite, the HP cone crushers offer versatility, allowing users to change rotational speeds and liner configurations quickly and easily. This gives the potential for changing the machines from coarse to extra-fine crushing, depending on the product specifications needed.
Metso points out the HP4 and HP5 have an advanced fastening system for the mantle and bowl liner that makes backing material unnecessary, and makes liner changes faster. When liners are changed or the crusher is reconfigured, the same hydraulic motors that rotate the bowl for setting adjustment will rotate the bowl completely out of the adjustment ring threads, greatly simplifying liner replacement.
The Technology Develops E&MJ asked each of the major manufacturers for their perspective on various aspects of cone-crusher technology, from developments that have taken place over the recent past, to the way ahead in crusher design and the potential impact of other players in what is currently a tightly-held market.
Asked to summarize the major developments that there have been in cone crusher design over the past 10 years, Jouni Mhnen, product manager for cone crushers at Metso Minerals, said wear-part developmentin terms of both materials and liner profileshas been remarkable over recent years, and will continue. The pressure is huge to provide long-lasting liners, while consistent performance over the liner lifetime is very important in liner development, he said.
The development of high reduction ratios has also been important. The recent HP-range developments have been the HP4 and HP5. The technological innovation in these machines is the full utilization of cone-crusher parameters and theory in practice, Mhnen said.
Higher reduction ratios and greater yields mean that this a way reduce the number of operating machines, with a new-generation unit capable of replacing a larger old-technology cone crusher, or two of the same head diameter.
John Olsen, vice president for international sales at Astec Industries, agreed. Telsmith cone crushers have been improved through an increased use of automation, by designing higher horsepower machines with a more efficient use of the power, and by making smaller machines more efficient through geometry and speed of crushing, he said.
From Sandviks perspective, major improvements have been made to further optimize the overall design, improve the crushing chambers, increase power, increase the crushing force, improve durability, improve serviceability (i.e., increased safety, ease of access) and improve the strength and wear-resistance of materials. Torbjrn Nilsson Wulff, the companys product line manager for mining cone crushers, added that advances in setting regulation (such as Sandviks ASRi) have also been introduced. All of these major developments have led to significant productivity gains, he said.
Fred Gross, global product director for minerals at FLSmidth, looked at some of the technical achievements from a hardware point of view, listing innovations such as the optimization of gradation control, the development of superior bronze bearing technology, and the design of high-strength load-bearing components. Production versatility has also improved markedly, he said, while other major advances have come with the development of fail-safe hydraulics to ensure protection from mechanical overload, and the counter-clockwise rotation feature adopted by the company in its cone-crusher designs, which prevents the cone from self-tightening when movement in the adjustment ring becomes excessive.
Optimizing Performance Mhnen (Metso): Crusher effective stroke adjustment through changing the eccentricity or speed is definitely the way to adjust the throughput capacity to production needs and utilize the crusher installed power. The active setting adjustment is needed for end product calibration. The shape of the end product is managed by controlling the crusher kinematics, which means all of the available parameters, together with liner profile design.
A cone crusher can be optimized (proper liner configurations, speed and kinematics) for maximum performance when the feed distribution and ore characteristics are constant. However, in the real world the feed distribution and ore characteristics are always varying. Crusher designs today are well-suited for optimizing cone crusher performance, especially when product sizing requirements are critical, with the ability to vary and hold settings. It is often the case that crusher performance can be optimized most effectively by having proper screening, plant layout and feed-control arrangements.
Crusher wear-part material development is targeting for longer lifetimes. While new, harder and more abrasion-resistant materials are being developed all the time, the manufacturing application of cone-crusher wear parts is demanding, so the manufacturing techniques need to be developed as well.
Automation and control support the crusher when the feed is consistent, or react and adjust it when the feed becomes unstable. In both cases, automation helps to optimize the crushers performance, giving consistent, predictable production of the end products that are wanted. The development of sensor technologies will provide more opportunities for smart adjustment of both the crusher and other machinery near it.
Nilsson Wulff (Sandvik): Specialization will increase efficiencies. By optimizing and designing a crusher to match a customers applications, cone crushers will be more tailor-made, leading to increased production efficiencies. Robust structural design of the bottom shell, as well as using stronger alloys for key components, will result in a better product for mining customers.
Robust sealing to the inner crusher mechanics provides more effective protection against dust and other unwanted particlesreducing maintenance and increasing the life of the crusher. An over-pressure system to keep the lubrication oil clean, hence increasing the time between servicing and reducing the number of oil changes, will also contribute to increased productivity.
In terms of control and automation, Sandviks cone crushers provide automatic overload protection. A combination of Hydroset and ASRi offers possibilities of true automation of the setting, facilitating online adjustment during full load and ensuring peak performance at all times. Faster signal analysis and response time could further improve operational efficiencies, while the external monitoring of auxiliary systems could also help optimize cone-crusher performance.
Olsen (Telsmith): There have been substantial advances in the study of the effects of speed and throw on crusher performance, which have been incorporated into Telsmith cone crushers. There has also been a minimization of maintenance times and costs to provide a lower overall cost of operating. By monitoring our cone crushers out in the field, there has been continuous improvement regarding the life of wear components, and the endurance of critical components.
Improving the productivity of cone crushers by automating their key functions will allow them to operate at peak performance while crushing. Critical machine operational data must also be collected and tracked, and can then be used for real-time protection, diagnostics, operational and maintenance adjustments.
Making Maintenance Safer Nilsson Wulff (Sandvik): Like all mining equipment, proper and regular scheduled maintenance is required in order to reduce unwanted breakdowns that can lead to major unexpected production costs. Lubrication is absolutely vital, and an off-line filtration unit increases up-time and wear life and cuts operating costs.
Mhnen (Metso): Generally maintenance should be made as easy and safe as possible. This means components need to be developed that have lower maintenance requirements and/or safe and easy accessibility. Crusher lubrication plays the most important role in respect to sensitiveness for crusher failure, so the lube unit and monitoring the oil flow and quality is important.
Maintenance is an area of challenge, especially for mining-size crushers; as crushing equipment becomes larger, the individual components get larger as well. Transport restrictions makes optimizing the completeness of crusher component/assemblies (as far as installation is concerned) limited. Having said that, in some parts of the world Metso has been very successful in terms of being fitter-friendly, with MP1000 cone crushers being completely assembled before delivery to site.
Health and safety are very important for everyone operating with crushing equipment. The development of safe lifting tools is important, as the components that need to be liftedsuch as wear partsare very special, and cannot be lifted with hook and chain. Metso will be launching a new mantle-lifting tool for its HP cone crushers in 2011.
Olsen (Telsmith): Serviceability is the key here. Telsmith believes ease of maintenance is critical for our customers. That is why we are focusing on lengthening maintenance cycles and making common maintenance components more fitter-friendly, enabling our customers to perform most routine maintenance.
Future Development: The Five-Year Forecast Mhnen (Metso): One area of development is improving crushing diagnostics and crusher performance status-monitoring even more than today. Automation will develop all of the time when other industries develop sensor techniques that can be used in the crushing industry.
The critical factors in cone-crusher design are the head diameter, head angle, length of stroke and eccentric speed. By understanding the combination of previous, you can choose the direction of cone-crusher development.
The development of cone crushers will continue in the direction where operating costs per ton will be the lowest. This means more production from less, with wear-part profile development having big potential for energy saving in terms of kWh/ton.
Olsen (Telsmith): A key area for improvement will be improving the life of wear materials within the crusher itself. Telsmith is also utilizing increased automation to improve the efficiency of its cone crushers.
Nilsson Wulff (Sandvik): Specialization increases efficiency. The specially designed, strength-optimized top shell and dedicated crushing chambers of Sandviks new CH895 model, for instance, make it ideal for tertiary and pebble crushing, while the new CH890 model uses a top shell and crushing chambers dedicated to secondary crushing. Both units have more power and increased crushing force in order to increase productivity.
The new main shaft, made from a new high strength material, is designed to withstand harsh mining conditions. The strength-optimized bottom shell design allows for greater loads, while the heavy-duty structural design ensures durability and longevity in the most demanding mining conditions.
Wider Applications for Cone Crushers? Nilsson Wulff (Sandvik): Crushing in stages, as an alternative to SAG milling, generates the same size reduction but with a lower total power consumption (crushing vs. milling). Rising energy costs and the benefits of cone crushers to reduce operating costs will hopefully shift the landscape in favor of crushing circuits.
Mhnen (Metso): Applications are getting wider all of time, especially where recycling raw materials from different industries needs particle breakage and re-utilization in the original industrial process. Slag, ferrochrome and demolished concrete are just three examples. The crushing of high-temperature feed material is one specific requirement, and Metso is developing sustainable optional solutions that can be used with our standard cone crushers.
Automation Benefits Mhnen (Metso): Most of our customers choose our cone-crusher automation package. The reason for the success and widespread use of our crusher automation system is that it has been developed to control our selected components, and it provides correct and safe start-up sequences (lube unit pump, discharge conveyor, crusher, feeder and so on) and shut-down sequences in a similar way. It monitors the crusher status, so the power draw, pressure levels and temperatures are in the right area.
Automatic wear compensation keeps the crusher setting constant even if the CSS increases because of lining wear. Feed level control keeps the crusher choke-fed, and the feed level at a selected point to provide consistent crushing. In summary, we can say automation gives better availability, efficiency and consistency, as well as safety in cone-crusher operation.
A technical paper presented by Metso at the Procemin 2010 seminar in Chile on Cavity Level Effect on Cone Crusher Performance and Production reported the results of experiments that proved the benefits and productivity gain of having controlled feed levels in the crushing cavity.
Olsen (Telsmith): On average, Telsmith customers realize a 10%15% improvement in productivity with automation. Automating key functions like maintaining the crusher settings throughout the operation will maximize the net finished product while minimizing the re-crush load.
Nilsson Wulff (Sandvik): With ASRi, the actual load inside the crusher is continuously monitored. This makes it possible to optimize crusher utilization, allowing our customers to squeeze the ultimate performance from their machine at all times. The system also keeps track of liner wear, making it easy to plan liner changes and minimize interruptions in production. Finally, the ASRi system can be integrated with sophisticated plant-control systems.
Sandviks Hydroset system provides safety and setting adjustment functions, and incorporates a heavy-duty hydraulic cylinder that supports the main shaft and adjusts its position. The system also provides automatic overload protection to allow tramp iron or other uncrushable material to pass through.
What About Competition from China? A quick Web search revealed a number of mainly Shanghai-based manufacturers who are offering cone crushers to the international market. E&MJ asked each of the respondents who participated in this article for their views on the potential threat these pose to the established suppliers.
Expressing Telsmiths point of view, John Olsen said: Our Chinese competitors are continuing to improve the quality of their product offerings, increasing overall market share in both the aggregate and mining sectors.
From Metso, Jouni Mhnen said: At the moment, the clear trend is that the Chinese companies are focusing heavily on the construction segment, with only limited impact on the mining segment. We have seen the Chinese companies produce old-technology machinery we rejected decades ago. However, the threat is obvious as their strategy can change almost overnight. Globally I can see that serious mining and construction customers trust our product knowledge, development skills and industrial benchmark. They appreciate the skills we have to develop new products, systems and automation that are always targeting the lowest operation cost/ton in the market. This is still our strength.
His view was reinforced by Torbjrn Nilsson Wulff at Sandvik. Any new competitor is a threat, but Sandviks mining offering goes beyond just supplying cone crushers. Continuous investments in research and development produce a constant flow of innovative technical features. By combining intelligent technology, advanced engineering skills and service and support, the outcome is maximum productivity for our customers.
Despite todays tightly held supply position, cone crusher technology continues to evolve, with the worlds leading manufacturers all investing in the development of new innovations that will make the concept more productive and cost-effective. Add to that the widening application field, and it is clear cone crushers will continue to be a key component of comminution circuits for both mining and aggregates production.
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In aggregates crushing field, aggregates mainly comes from the crushing of high-hardness materials such as basalt and granite. But one thing cannot be ignoredthere has higher requirements on capacity and bearing strength of the crushing equipment when processing these materials. This leads to higher costs for processing these materials. But cone crusher greatly reduces the cost of producing aggregates.
HST Single-cylinder Hydraulic Cone Crusher achieves higher production efficiency and better product quality by matching suitable crushing cavity, eccentric distance and movement parameters. Combined with optimized strength and high-quality components, HST Hydraulic Cone Crusher has bigger holding capacity and crushing ratio as well as stronger throughput capability.
The fully automatic control system equipped on the HST Cone Crusher can provide manual control, constant discharge opening control, constant power control and many other operation modes for users to select. It can continuously monitor the internal actual load of the crusher to optimize the use ratio of the crusher and allow it to play its best performance at all times.
HST Hydraulic Cone Crusher has a simple structure. Almost all checks and maintenances can be done by only taking down the upper rack. The structure can not only make maintenances and checks get easier, but also save maintenance costs a lot. Besides, HST Single-cylinder Hydraulic Cone Crusher is compact on its structure, occupying small floor area, which further cuts expenditures on the foundation building.
Seeing this, do you think HST cone crusher is excellent? If you want to learn more about HST price and other information, you can leave a message online for consultation, and we will have professionals to answer your questions in time.
In the quarry, crushing is handled in four potential stages: primary, secondary, tertiary and quaternary. The reduction of aggregate is spread over these stages to better control the product size and quality, while minimizing waste.
The primary stage was once viewed merely as a means to further reduce stone following the blast or excavation prior to secondary crushing. Today, primary crushing is viewed as more important within the balance of production and proper sizing needs. The size and type of the primary crusher should be coordinated with the type of stone, drilling and blasting patterns, and the size of the loading machine. Most operations will use a gyratory, jaw or impact crusher for primary crushing.
In the secondary and subsequent stages, the stone is further reduced and refined for proper size and shape, mostly based on specifications to produce concrete and asphalt. Between stages, screens with two or three decks separate the material that already is the proper size. Most secondary crushers are cone crushers or horizontal-shaft impact crushers. Tertiary and quaternary crushers are usually cone crushers, although some applications can call for vertical-shaft impact crushers in these stages.
A gyratory crusher uses a mantle that gyrates, or rotates, within a concave bowl. As the mantle makes contact with the bowl during gyration, it creates compressive force, which fractures the rock. The gyratory crusher is mainly used in rock that is abrasive and/or has high compressive strength. Gyratory crushers often are built into a cavity in the ground to aid in the loading process, as large haul trucks can access the hopper directly.
Jaw crushers are also compression crushers that allow stone into an opening at the top of the crusher, between two jaws. One jaw is stationary while the other is moveable. The gap between the jaws becomes narrower farther down into the crusher. As the moveable jaw pushes against the stone in the chamber, the stone is fractured and reduced, moving down the chamber to the opening at the bottom.
The reduction ratio for a jaw crusher is typically 6-to-1, although it can be as high as 8-to-1. Jaw crushers can process shot rock and gravel. They can work with a range of stone from softer rock, such as limestone, to harder granite or basalt.
As the name implies, the horizontal-shaft impact (HSI) crusher has a shaft that runs horizontally through the crushing chamber, with a rotor that turns hammers or blow bars. It uses the high-speed impacting force of the turning blow bars hitting and throwing the stone to break the rock. It also uses the secondary force of the stone hitting the aprons (liners) in the chamber, as well as stone hitting stone.
With impact crushing, the stone breaks along its natural cleavage lines, resulting in a more cubical product, which is desirable for many of todays specifications. HSI crushers can be primary or secondary crushers. In the primary stage, HSIs are better suited for softer rock, such as limestone, and less abrasive stone. In the secondary stage, the HSI can process more abrasive and harder stone.
Cone crushers are similar to gyratory crushers in that they have a mantle that rotates within a bowl, but the chamber is not as steep. They are compression crushers that generally provide reduction ratios of 6-to-1 to 4-to-1. Cone crushers are used in secondary, tertiary and quaternary stages.
With proper choke-feed, cone-speed and reduction-ratio settings, cone crushers will efficiently produce material that is high quality and cubical in nature. In secondary stages, a standard-head cone is usually specified. A short-head cone is typically used in tertiary and quaternary stages. Cone crushers can crush stone of medium to very hard compressive strength as well as abrasive stone.
The vertical shaft impact crusher (or VSI) has a rotating shaft that runs vertically through the crushing chamber. In a standard configuration, the VSIs shaft is outfitted with wear-resistant shoes that catch and throw the feed stone against anvils that line the outside of the crushing chamber. The force of the impact, from the stone striking the shoes and anvils, fractures it along its natural fault lines.
VSIs also can be configured to use the rotor as a means of throwing the rock against other rock lining the outside of the chamber through centrifugal force. Known as autogenous crushing, the action of stone striking stone fractures the material. In shoe-and-anvil configurations, VSIs are suitable for medium to very hard stone that is not very abrasive. Autogenous VSIs are suitable for stone of any hardness and abrasion factor.
Roll crushers are a compression-type reduction crusher with a long history of success in a broad range of applications. The crushing chamber is formed by massive drums, revolving toward one another. The gap between the drums is adjustable, and the outer surface of the drum is composed of heavy manganese steel castings known as roll shells that are available with either a smooth or corrugated crushing surface.
Double roll crushers offer up to a 3-to-1 reduction ratio in some applications depending on the characteristics of the material. Triple roll crushers offer up to a 6-to-1 reduction. As a compressive crusher, the roll crusher is well suited for extremely hard and abrasive materials. Automatic welders are available to maintain the roll shell surface and minimize labor expense and wear costs.
These are rugged, dependable crushers, but not as productive as cone crushers with respect to volume. However, roll crushers provide very close product distribution and are excellent for chip stone, particularly when avoiding fines.
Hammermills are similar to impact crushers in the upper chamber where the hammer impacts the in-feed of material. The difference is that the rotor of a hammermill carries a number of swing type or pivoting hammers. Hammermills also incorporate a grate circle in the lower chamber of the crusher. Grates are available in a variety of configurations. The product must pass through the grate circle as it exits the machine, insuring controlled product sizing.
Hammermills crush or pulverize materials that have low abrasion. The rotor speed, hammer type and grate configuration can be converted for different applications. They can be used in a variety of applications, including primary and secondary reduction of aggregates, as well as numerous industrial applications.
Virgin or natural stone processing uses a multi-stage crushing and screening process for producing defined aggregate sizes from large lumps of rock. Such classified final fractions are used as aggregates for concrete, asphalt base, binder and surface course layers in road construction, as well as in building construction. The rock is quarried by means of drilling and blasting. There are then two options for processing the bulk material after it has been reduced to feeding size of the crushing plant: mobile or stationary plants.
When stone is processed in mobile primary crushing plants, excavators or wheel loaders feed the rock into the crusher that is set up at the quarry face, gravel pit or in a recycling yard or demolition site. The crushed material is then either sent to the secondary/tertiary processing stage via stacking conveyors or transported by trucks. Some mobile crushers have an independent secondary screen mounted on the unit, effectively replacing a standalone screen.
The higher the compressive strength of rock, the higher also is its quality, which plays an important role particularly in road construction. A materials compressive strength is delineated into hard, medium-hard or soft rock, which also determines the crushing techniques used for processing to obtain the desired particle sizes.
The materials quality is influenced significantly by particle shape. The more cubic-shaped the individual aggregate particles are, the better the resulting particle interlock. Final grains of pronounced cubic shape are achieved by using several crushing stages. A cubicity showing an edge ratio of better than 1-to-3 is typical of high-quality final aggregate.
As the earths natural resources are becoming ever more scarce, recycling is becoming ever more important. In the building industry, recycling and reuse of demolition concrete or reclaimed asphalt pavement help to reduce the requirements for primary raw materials. Mobile impact and jaw plants are uniquely positioned to produce high-quality reclaimed asphalt pavement (RAP) and recycled concrete aggregate (RCA) for reuse in pavements, road bases, fill and foundations.
Use of RAP and RCA is growing dramatically as road agencies accept them more and more in their specs. But because RAP and RCA come from a variety of sources, to be specified for use by most departments of transportation they must be processed or fractionated and characterized into an engineered, value-added product. RCA or RAP are very commonly crushed and screened to usable sizes often by impact crushers and stored in blended stockpiles that can be characterized by lab testing for use in engineered applications.
Impact crushers are increasingly used for crushing recycling material. Impact crushers are capable of producing mineral aggregate mixes in one single crushing stage in a closed-cycle operation, making them particularly cost-effective. Different crusher units can alternatively be combined to process recycling material. A highly efficient method of processing recycling material combines crushing, screening and separation of metals. To produce an end product of even higher quality, the additional steps of washing to remove light materials such as plastics or paper by air classification and via electromagnetic metal separator are incorporated into the recycling process.
Mobile impact crushers with integrated secondary screens or without integrated screen used in conjunction with an independent mobile screen are ideal for producing large volumes of processed, fractionated RAP or RCA on a relatively small footprint in the plant. Mobile impactors are especially suited for RAP because they break up chunks of asphalt pavement or agglomerations of RAP, rather than downsize the aggregate gradation. Compression-type crushers such as jaws and cones can clog due to packing (caking) of RAP when the RAP is warm or wet.
Contaminants such as soil are part of processing demolition concrete. Mobile impact and jaw crushers when possessing integrated, independent prescreens removing dirt and fines before they ever enter the crushing circuit reduce equipment wear, save fuel, and with some customers, create a salable fill byproduct. A lined, heavy-duty vibrating feeder below the crusher can eliminate belt wear from rebar or dowel or tie bar damage. If present beneath the crusher, this deflector plate can keep tramp metal from degrading the conveyor belt. That way, the feeder below the crusher not the belt absorbs impact of rebar dropping through the crusher.
These mobile jaw and impact crushers may feature a diesel and electric-drive option. In this configuration, the crusher is directly diesel-driven, with the conveyor troughs, belts and prescreen electric-driven via power from the diesel generator. This concept not only reduces diesel fuel consumption, but also results in significantly reduced exhaust emissions and noise levels. This permits extremely efficient operation with low fuel consumption, allowing optimal loading of the crusher.
Jaw crushers operate according to the principle of pressure crushing. The raw feed is crushed in the wedge-shaped pit created between the fixed crusher jaw, and the crusher jaw articulated on an eccentric shaft. The feed material is crushed by the elliptic course of movement and transported downwards. This occurs until the material is smaller than the set crushing size.
Jaw crushers can be used in a wide range of applications. In the weight class up to 77 tons (70 metric tons), they can be used for both virgin stone and recycled concrete and asphalt aggregates processing as a classic primary crusher for natural stone with an active double-deck grizzly, or as a recycling crusher with vibrating discharge chute and the crusher outlet and magnetic separator.
Output for mobile jaw crushers ranges from 100 to 1,500 tph depending on the model size and consistency of the feed material. While larger mobile crushers produce more aggregate faster, transport weights and dimensions may limit how easily the crusher can be shipped long distances. Mobile jaw crushers can have either a vibratory feeder with integrated grizzly, or a vibrating feeder with an independent, double-deck, heavy-duty prescreen. Either way, wear in the system is reduced because medium and smaller gradations bypass the crusher, with an increase in end-product quality because a side-discharge conveyor removes fines. A bypass flap may provide easy diversion of the material flow, eliminating the need for a blind deck.
Jaw crusher units with extra-long, articulated crusher jaws prevent coarse material from blocking while moving all mounting elements of the crusher jaw from the wear area. A more even material flow may be affected if the transfer from the prescreen or the feeder trough is designed so material simply tilts into the crushing jaw.
Mobile jaw and impact crushers alike can be controlled by one operator using a handheld remote. The remote also can be used to move or relocate the crusher within a plant. In other words, the crusher can be run by one worker in the cab of an excavator or loader as he feeds material into the crusher. If he sees something deleterious going into the hopper, he can stop the crusher.
Impact crushing is totally different from pressure crushing. In impact crushing, feed material is picked up by a fast moving rotor, greatly accelerated and smashed against an impact plate (impact toggle). From there, it falls back within range of the rotor. The crushed material is broken again and again until it can pass through the gap between the rotor and impact toggle.
A correctly configured mobile jaw or impact crusher will enhance material flow through the plant and optimize productivity. New-design mobile jaw and impact crushers incorporate a highly efficient flow concept, which eliminates all restriction to the flow of the material throughout the entire plant. With this continuous-feed system, each step the material goes through in the plant is wider than the width of the one before it, eliminating choke or wear points.
For example, a grizzly feeder can be wider than the hopper, and the crusher inlet wider than the feeder. The discharge chute under the crusher is 4 inches wider than the inner width of the crusher, and the subsequent discharge belt is another 4 inches wider than the discharge chute. This configuration permits rapid flow of crushed material through the crusher. Also, performance can be significantly increased if the conveying frequencies of the feeder trough and the prescreen are adapted independently to the level of the crusher, permitting a more equal loading of the crushing area. This flow concept keeps a choke feed to the crusher, eliminating stops/starts of the feed system, which improves production, material shape and wear.
Users are focused on cost, the environment, availability, versatility and, above all, the quality of the end product. Simple crushing is a relatively easy process. But crushing material so that the particle size, distribution and cleanliness meet the high standards for concrete and asphalt requires effective primary screening, intelligent control for optimal loading, an adjustable crusher with high drive output, and a screening unit with oversize return feed.
This starts with continuous flow of material to the crusher through a variable-speed control feeder. Having hopper walls that hydraulically fold integrated into the chassis makes for quick erection of hopper sides on mobile units. If available, a fully independent prescreen for either jaw or impact models offers the ability to effectively prescreen material prior to crushing this allows for product to be sized prior to crushing, as opposed to using a conventional vibrating grizzly. This has the added value of increasing production, reducing wear costs and decreasing fuel consumption.
This independent double-deck vibrating screen affects primary screening of fines and contaminated material via a top-deck interchangeable punched sheet or grizzly, bottom-deck wire mesh or rubber blank. Discharged material might be conveyed either to the left or to the right for ease of positioning. The independent double-deck vibrating prescreen improves flow of material to the crusher, reducing blockages and feed surges.
Modern electrical systems will include effective guards against dust and moisture through double-protective housings, vibration isolation and an overpressure system in which higher air pressure in the electrical box keeps dust out. Simple and logical control of all functions via touch panel, simple error diagnostics by text indicator and remote maintenance system all are things to look for. For crushing demolition concrete, look for a high-performance electro- or permanent magnet with maximum discharge capacity, and hydraulic lifting and lowering function by means of radio remote control.
For impact crushers, a fully hydraulic crusher gap setting with automatic zero-point calculation can speed daily set-up. Featured only on certain mobile impact crushers, a fully hydraulic adjustment capability of the crushing gap permits greater plant uptime, while improving quality of end product.
Not only can the crushing gap be completely adjusted via the touch panel electronic control unit, but the zero point can be calculated while the rotor is running. This ability to accurately set the crusher aprons from the control panel with automatic detection of zero-point and target-value setting saves time, and improves the overall efficiency and handling of the crusher. On these mobile impact crushers, the zero point is the distance between the ledges of the rotor and the impact plates of the lower impact toggle, plus a defined safety distance. The desired crushing gap is approached from this zero point.
While the upper impact toggle is adjusted via simple hydraulic cylinders, the lower impact toggle has a hydraulic crushing gap adjustment device, which is secured electronically and mechanically against collision with the rotor. The crushing gap is set via the touch screen and approached hydraulically. Prior to setting of the crushing gap, the zero point is determined automatically.
For automatic zero-point determination with the rotor running, the impact toggle moves slowly onto the rotor ledges until it makes contact, which is detected by a sensor. The impact toggle then retracts to the defined safe distance. During this procedure, a stop ring slides on the piston rod. When the zero point is reached, the locking chamber is locked hydraulically and the stop ring is thus fixed in position. The stop ring now serves as a mechanical detent for the piston rod. During the stop ring check, which is carried out for every crusher restart, the saved zero point is compared to the actual value via the electronic limit switch. If the value deviates, a zero-point determination is carried out once again.
These impact crushers may feature a new inlet geometry that allows even better penetration of the material into the range of the rotor. Also, the wear behavior of the new C-form impact ledges has been improved to such an extent that the edges remain sharper longer, leading to improved material shape.
The machines come equipped with an efficient direct drive that improves performance. A latest-generation diesel engine transmits its power almost loss-free directly to the crushers flywheel, via a fluid coupling and V-belts. This drive concept enables versatility, as the rotor speed can be adjusted in four stages to suit different processing applications.
Secondary impact crushers and cone crushers are used to further process primary-crushed aggregate, and can be operated with or without attached screening units. These crushers can be used as either secondary or tertiary crushers depending on the application. When interlinked to other mobile units such as a primary or screen, complicated technical processing can be achieved.
Mobile cone crushers have been on the market for many years. These machines can be specially designed for secondary and tertiary crushing in hard-stone applications. They are extraordinarily efficient, diverse in application and very economical to use. To meet the diverse requirements in processing technology, mobile cone crushing plants are available in different sizes and configurations. Whether its a solo cone crusher, one used in addition to a triple-deck screen for closed-loop operation, or various-size cone crushers with a double-deck screen and oversize return conveyor, a suitable plant will be available for almost every task.
Mobile cone crushers may be available with or without integrated screen units. With the latter, an extremely efficient triple-deck screen unit may be used, which allows for closed-loop operation and produces three final products. Here the screen areas must be large so material quantities can be screened efficiently and ensure that the cone crusher always has the correct fill level, which is particularly important for the quality of the end product.
Mobile, tracked crushers and screen plants are advancing into output ranges that were recently only possible using stationary plants. Previously, only stationary plants were used for complicated aggregate processing applications. But thanks to the advancements made in machine technology, it is becoming increasingly possible to employ mobile technology for traditional stationary applications.
Mobile crushers are used in quarries, in mining, on jobsites, and in the recycling industry. These plants are mounted on crawler tracks and can process rock and recycling material, producing mineral aggregate and recycled building materials respectively for the construction industry. A major advantage of mobile crushers is their flexibility to move from one location to the next. They are suitable for transport, but can also cover short distances within the boundaries of their operating site, whether in a quarry or on the jobsite. When operating in quarries, they usually follow the quarry face, processing the stone directly on site.
For transport over long distances to a new location or different quarry, mobile crushers are loaded on low trailers. No more than 20 minutes to an hour is needed for setting the plant up for operation. Their flexibility enables the mobile crushers to process even small quantities of material with economic efficiency.
Mobile plants allow the combination of prescreening that prepares the rock for the crushing process and grading, which precisely separates defined aggregate particle sizes into different end products to be integrated with the crushing unit into one single machine. In the first stage, the material is screened using an active prescreen. After prescreening, it is transferred to the crusher, from where it is either stockpiled via a discharge conveyor or forwarded to a final screen or a secondary crushing stage. Depending on the specified end product, particles are then either graded by screening units or transported to additional crushing stages by secondary or tertiary impact crushers or cone crushers. Further downstream screening units are used for grading the final aggregate fractions.
The process of prescreening, crushing and grading is a common operation in mobile materials processing and can be varied in a number of ways. Mobile crushers with up to three crushing stages are increasingly used in modern quarries. Different mobile crushing and screening plants can be combined for managing more complex crushing and screening jobs that would previously have required a stationary crushing and screening plant.
Interlinked mobile plants incorporate crushers and screens that work in conjunction with each other, and are coordinated in terms of performance and function. Mining permits are under time constraints and mobile plants provide faster setup times. They provide better resale value and reusability, as mobile plants can also be used individually. They also reduce operating costs in terms of fewer haul trucks and less personnel.
With a so-equipped mobile crusher, the feed operator can shut the machine down or change the size of the material, all using the remote control, or use it to walk the crusher from one part of the site to the other, or onto a flat bed trailer for relocation to a different quarry or recycling yard. This reduces personnel and hauling costs compared to a stationary plant. With the mobile jaw or impact primary crusher, the only additional personnel needed would be a skid-steer operator to remove scrap steel, and someone to move the stockpiles.
Thanks to better technology, mobile plants can achieve final aggregate fractions, which previously only were possible with stationary plants. Production availability is on par with stationary plants. Theyre applicable in all quarries, but can be used for small deposits if the owner has several quarries or various operation sites. For example, an operator of several stone quarries can use the plants in changing market situations at different excavation sites. In addition, they also can be used as individual machines. A further factor is that mobile plants, in general, require simpler and shorter licensing procedures.
The high cost of labor keeps going up. A stationary crusher might be able to produce multiple times the amount of product, but also would require about seven or eight workers. Aggregate producers can benefit when producing material with the minimized crew used for mobile jaw and impact crushers.
Using correct maintenance practices, mobile crushers will remain dependable throughout their working life. Crushing and processing material can result in excessive wear on certain components, excessive vibration throughout the plant, and excessive dust in the working environment. Some applications are more aggressive than others. A hard rock application is going to require more maintenance on top of standard maintenance, as there will be more vibration, more dust and more wear than from a softer aggregate.
Due to the nature of its purpose, from the moment a mobile crusher starts, the machine is wearing itself out and breaking itself down. Without routine, regular maintenance and repair, a mobile crusher will not be reliable nor provide the material customers demand.
The first area of wear on any machine is the feed system. Whether its a feeder with an integrated grizzly, or a feeder with an independent prescreen, how the machine is fed contributes to wear. When setting up and maintaining a machine, the machine must be level. A machine that is unlevel left to right will experience increased wear on all components, including the feeder, the screens, the crushing chambers and the conveyor belts. In addition, it reduces production and screening efficiency, as the whole area of the machine is not being effectively used. Also, having the machine sit high at the discharge end will have the effect of feeding the material uphill in the feeder and reducing its efficiency, thus reducing production.
Another area for consideration is the equipment used to feed the machine. The operator using a loader to feed the crusher will have no control over the feed size, as he cannot see whats in the bucket. Whereas with an excavator, the operator can see whats inside and has more control over the feed into the hopper. That is, the operator is not feeding so much material all at once and is controlling the size of the feed. This reduces wear in the feed hoppers impact zones and eliminates material blockages due to feed size being too large to enter the chamber.
Dust is a problem in its own right, especially for the power plant of the mobile crusher. In a very dusty application, it is easy to plug the radiator and have engine-overheating problems. High dust levels cause increased maintenance intervals on air filters, and if not controlled properly, can enter the diesel tank and cause problems with the fuel system. Also, dust that gets inside the crusher increases wear. But if systems are put in place to remove the dust, it should keep it from going into the machine in the first place.
Dust also is a hazard on walkways and a problem for conveyors. If maintained, side-skirting and sealing the conveyors keeps dust from spilling out, building up underneath the conveyor, or building up in rollers, pulleys, bearings, and causing wear on shafts. Its important to maintain the sealing rubbers on the conveyor belts to avoid those issues. Routine maintenance calls for removing accumulated dust from inside and under the machine.
Dust also is a problem for circuit boards and programmable controllers. Dust causes electrical switches to malfunction because it stops the contacts from correctly seating. Electrical systems under positive air pressure dont permit dust to penetrate the control system. In control panels with a correctly maintained positive pressure system, filters remove dust from air that is being pumped into the cabinets. If the filters are plugged, the system will not pull as much air through, allowing dust, moisture and heat to build in the cabinet.
There are also impact aprons against which the rock is thrown, which also see high wear. There are side plates or wear sheets on the sides of the machine. The highest wear area is around the impact crusher itself, around the circumference of the rotor. If not maintained, the wear items will wear through and compromise the structure of the crusher box.
Conduct a daily visual check of the machine. The jaw is simple; just stand up on the walkway and take a look down inside. A crushers jaw plate can be flipped so there are two sides of wear on them. Once half the jaw is worn out, flip it; once that side is worn, change it.
The impact crusher will have an inspection hatch to see inside. Check to see how much material is left on the blow bars and how much is left on the wear sheets on the side of the crusher box. If half the bar is worn out after one week, change the blow bars in another week.The frequency of changes depends entirely on the application and the rock that is being crushed.
They have to be user serviceable, user friendly, and able to be changed in a short time. The best way to change these parts is a service truck with a crane; some use excavators but thats not recommended by any means.
After initial blasting, breakers are used to break down aggregate that typically is not only too large to be hauled in dump trucks, but also too large for crushers that size rock to meet asphalt, drainage system, concrete and landscaping specifications. Breakers can be mounted to a mobile carrier, such as an excavator, or to stationary boom systems that can be attached to a crusher. The total number of hydraulic breakers can vary from site to site depending on production levels, the type of aggregate materials and the entire scope of the operation.
Without hydraulic breakers, workers rely on alternative practices that can quickly affect production rates. For instance, blasting mandates shutting down operations and moving workers to a safe location. And when you consider how many times oversize aggregate might need to be reduced, this can lead to a significant amount of downtime and substantially lower production rates.
Aggregate operations can use hydraulic breakers to attack oversize without having to clear the quarry. But with an ever-growing variety of manufacturers, sizes and models to choose from, narrowing the decision to one hydraulic breaker can be overwhelming with all of the stats and speculation. Thats why its important to know what factors to consider before investing in a new hydraulic breaker.
In most cases, heavy equipment dealers are very knowledgeable about quarry equipment, including breakers, so they are a good resource for finding the best model for a carrier, usually an excavator or stationary boom system. More than likely, they will have specifications and information about various breaker sizes to help gauge what model is best. But being familiar with what to look for in a breaker can streamline the selection process.
The best places to look for breaker information are in the manufacturers brochure, website, owners manual or catalogue. First, carefully review the carrier weight ranges. A breaker that is too big for the carrier can create unsafe working conditions and cause excessive wear to the carrier. An oversized breaker also transmits energy in two directions, toward the aggregate and through the equipment. This produces wasted energy and can damage the carrier. But using a breaker thats too small puts excessive force on the tool steel, which transmits percussive energy from the breaker to the material. Using breakers that are too small also can damage mounting adapters and internal components, which considerably decreases their life.
Once you find a breaker that meets the carriers capacity, check its output power, which is typically measured in foot-pounds. Foot-pound classes are generalizations and are not based on any physical test. Often the breakers output will be documented in one of two ways: as the manufacturers calculated foot-pound class or as an Association of Equipment Manufacturers measured foot-pound rating. Foot-pound class ratings can be deceiving since they are loosely based on the breakers service weight and not the result of any physical test. The AEM rating, on the other hand, measures the force a breaker exerts in a single blow through repeatable and certified testing methods. The AEM rating, which was developed by the Mounted Breaker Manufacturers Bureau, makes it easier to compare breaker models by reviewing true figures collected during an actual test procedure.
For instance, three breaker manufacturers might claim their breakers belong in a 1,000-lb. breaker class. But AEM testing standards could reveal all three actually have less foot-pound impact. You can tell if a breaker has been AEM tested if a manufacturer provides a disclosure statement or if the breaker is labeled with an AEM Tool Energy seal. If you cannot find this information, contact the manufacturer. In addition to output energy specifications, manufacturers often supply estimates for production rates on different types of aggregate material. Make sure to get the right measurements to make the best decision.
In addition to weight and output power, look at the breakers mounting package. Two things are crucial for mounting a breaker to a carrier: a hydraulic installation kit and mounting components. Breakers need hydraulic plumbing with unidirectional flow to move oil from the carrier to the breaker and back again. A one-way flow hydraulic kit is sufficient to power the breaker as long as the components are sized to properly handle the required flows and pressures. But, consider a bidirectional flow hydraulic kit if you plan to use the same carrier with other attachments that require two-way flow. Check with the dealer or breaker manufacturer to determine which hydraulic package best fits current and future needs.
Hydraulic flow and pressure specifications also need to be considered when pairing a breaker to a hydraulic system. If the carrier cannot provide enough flow at the right pressure, the breaker wont perform with maximum output, which lowers productivity and can damage the breaker. Additionally, a breaker receiving too much flow can wear quickly, which reduces its service life. For the best results, follow the hydraulic breaker specifications found in owners manuals, catalogs and brochures. Youll find out if a breaker has additional systems that might require additional servicing. For instance, some breakers feature nitrogen gas-assist systems that work with the hydraulic oil to accelerate the breakers piston. The nitrogen systems specifications need to be followed for consistent breaker power output.
Brackets or pin and bushing kits are commonly required to attach the breaker to the carrier. Typically they are bolted to the top of a breaker and are configured to match a specific carrier. Some manufacturers make universal mounting brackets that can accommodate two or three different sizes of carriers. With the adjustable pins, bushings or other components inside these universal brackets, the breaker can fit a range of carriers. However, varying distances between pin centers can complicate hookups to quick coupling systems. In addition, loose components, such as spacers, can become lost when the breaker is not in use and detached from the carrier.
Some carriers are equipped with quick-coupling systems, which require a breakers mounting interface to be configured like the carriers original attachment. Some manufacturers produce top-mount brackets that pair extremely well with couplers. This allows an operator to use the original bucket pins from the carrier to attach the breaker, and eliminates the need for new pins. This pairing also ensures a fast pickup with the quick coupler.
Its also a good idea to check which breaker tools are available through the dealer and manufacturer. The most common for aggregate mining are chisels and blunts. There are two kinds of chisels commonly used in aggregate mines: crosscut and inline. Both chisels resemble a flat head screwdriver, but the crosscut chisels are used when carrier operators want to direct force in a left-to-right concentration; whereas, inline chisels direct force fore and aft. With chisel tools, operators can concentrate a breakers energy to develop cracks, break open seams or define scribe lines.
If a chisel cant access or develop a crack or seam, a blunt can be used. Blunts have a flattened head that spreads the energy equally in all directions. This creates a shattering effect that promotes cracks and seam separation. Ask your dealer if the tools you are considering are suited for the application. Using non-original equipment manufacturer tool steel can damage the percussive piston in the breaker, seize into the wear bushings, or cause excessive wear.
Regular breaker maintenance is necessary, yet its one of the biggest challenges for aggregate operations. It not only extends the life of the breaker, but also can keep minor inconveniences from turning into expensive problems. Some manufacturers recommend operators inspect breakers daily to check grease levels and make sure there are no worn or damaged parts or hydraulic leaks.
Breakers need to be lubricated with adequate amounts of grease to keep the tool bushing area clear and reduce friction, but follow the manufacturers recommendations. For example, adding grease before properly positioning the breaker can lead to seal damage or even catastrophic failure. And too little grease could cause the bushings to overheat, seize and damage tools. Also, manufacturers advise using high-moly grease that withstands working temperatures greater than 500 degrees. Some breakers have automatic lube systems that manage grease levels, but those systems still need inspections to ensure there is adequate grease in their vessels. Shiny marks on the tool are a good indication the breaker is not properly lubricated.
Little has changed in basic crusher design over past decades, other than that of improvements in speed and chamber design. Rebuilding and keeping the same crusher in operation year after year has long been the typical approach. However, recent developments have brought about the advent of new hydraulic systems in modern crusher designs innovations stimulated by the need for greater productivity as well as a safer working environment. Importantly, the hydraulic systems in modern crusher designs are engineered to deliver greater plant uptime and eliminate the safety risks associated with manual intervention.
Indeed the crushing arena is a hazardous environment. Large material and debris can jam inside the crusher, damaging components and causing costly downtime. Importantly, manually digging out the crusher before repairs or restarts puts workers in extremely dangerous positions.
The Mine Safety and Health Administration has reported numerous injuries and fatalities incurred when climbing in or under the jaw to manually clear, repair or adjust the typical older-style jaw crusher. Consider that fatalities and injuries can occur even when the machine is locked out and tagged out. Recent examples include a foreman injured while attempting to dislodge a piece of steel caught in the primary jaw crusher. Another incident involved a fatality when a maintenance man was removing the toggle plate seat from the pitman on a jaw crusher. The worker was standing on a temporary platform when the bolts holding the toggle seat were removed, causing the pitman to move and strike him.
The hydraulic systems on modern crusher designs eliminate the need for workers to place themselves in or under the crusher. An overview of hydraulic system technology points to these three key elements:
A hydraulic chamber-clearing system that automatically opens the crusher to a safe position, allowing materials to pass. A hydraulic overload relief that protects parts and components against overload damage. A hydraulic adjustment that eliminates the maintenance downtime associated with manual crusher adjustments, and maintains safe, consistent crusher output without the need for worker intervention.
Whether a crusher is jammed by large material, tramp iron or uncrushable debris; or is stalled by a power failure the chamber must be cleared before restarting. Manual clearing is a lengthy and risky task, especially since material can be wedged inside the crusher with tremendous pressure, and dislodging poses much danger to workers placed in harms way inside the crusher.
Unlike that of the older-style jaw, the modern jaw will clear itself automatically with hydraulics that open the crusher to a safe position, and allow materials to pass again, without the need for manual intervention. If a feeder or deflector plate is installed under the crusher, uncrushable material will transfer smoothly onto the conveyor without slicing the belt.
To prevent crusher damage, downtime and difficult maintenance procedures, the hydraulic overload relief system opens the crusher when internal forces become too high, protecting the unit against costly component failure. After relief, the system automatically returns the crusher to the previous setting for continued crushing.
The modern crusher is engineered with oversized hydraulic cylinders and a traveling toggle beam to achieve reliable overload protection and simple crusher adjustment. All closed-side setting adjustments are made with push-button controls, with no shims being needed at any time (to shim is the act of inserting a timber or other materials under equipment). This is a key development as many accidents and injuries have occurred during shim adjustment, a process which has no less than 15 steps as described in the primary crusher shim adjustment training program offered by MSHA.
To get the most out of your cone crusher it is important to configure it correctly. Often this is viewed as some sort of dark art but with some basic guidance it is not that hard to do. This paper is intended to introduce the topic of crushing chamber selection and how to keep crushing performance high during the lifetime of the crushing chamber. The paper will also give guidance on what can be done to both detect and address some common problems. It is good to have some basic understanding so this paper starts off with some theory and then connects the theory into some practical applications.
In order to understand why certain things happens in the cone crusher it is good to have some insights in the actual crushing process. In this paper we will start up with a little bit of theory on what happens with the rocks as they pass through the crushing chamber.
During one revolution of the crusher the rock material will both fall and be crushed. The falling occurs from the moment the mantel starts to move away from the concave and ends when the mantle have closed enough to again grip the material. During the fall phase the material first falls freely and sometimes it also slides against the mantle. Once gripped the downward motion stops and the material is crushed. This process is repeated over and over until the material has reached the bottom of the crushing chamber and falls out. Each of these crushing events is often referred to as a crushing zone, see Figure 1.
Figure 1. The crushing zones. The material is first crushed in the first crushing zone, when the mantle moves away from the concave the material will fall into the second crushing zone and be crushed again. The process repeats itself until the material reach the bottom of the chamber and falls out of the crushing chamber.
Since the cavity formed by the mantel and concave have more or less of a funnel shape the size of the crushing zones will vary. The smaller the zone the less material can fit into it. In all crushers there will be a zone with smallest volume and that is referred to as the choke zone. The volume of the choke zone is what determines the crusher throughput capacity.
Often selection of a crushing chamber is regarding a bit of a mystery but in reality, it is not that hard to get the basics right. When starting the selection process there is one factor more important than all others: chamber max feed size. When selecting crushing chamber review the maximum feed size, the chamber should be selected so that the crushing chamber specified feed size is larger than the rock material max size. The chamber max feed size is not to be mistaken for chamber intake opening. So the specified max feed size will have some margins so no tolerance is needed when the chamber is selected. One exception from this might be if the rock material is extremely elongated or flat but those cases are rare.
In general the crushers ability to crush at a smaller setting gets better and better as the chamber becomes finer. If you look at the capacity table of different crushing chambers for a crusher you will notice that the minimum closed side setting (CSS) is smaller for a fine chamber compared to a coarse chamber. Often you want to be able to run the crusher at a small setting to efficiently crush the rock into the desired size and to do that a small CSS is needed.
Another thing worth noting about crushing chambers is that as they get coarser, they will have a larger capacity. Based on this one might be tempted to abandon the rule of selecting chamber based on feed size. It is easy to think that if you do not need the small CSS why do not select a coarser chamber and thereby increase the crusher capacity. This is totally feasible, but it will come at a price.
As mentioned above the second reason for selecting a crushing chamber based on feed size is wear. If a coarser than needed chamber is selected the material entering the crushing chamber will be significantly smaller than the intake opening. The consequence of this is that there will be no crushing in the upper part of the chamber, instead all crushing will take place further down in the chamber. No crushing in the upper part means no wear. All wear will instead be focused to the lower part of the crushing chamber. Again, if the material abrasiveness is low this might not be a big problem but for most plants the down time and effort to replace crusher wear parts has significant effect on productivity. So, in order to maximize wear part utilization and minimize downtime, it is important to select the chamber with the correct max feed size.
For a given crushing chamber there are often more than one mantle. They are often referred to as A and B mantle. (This is only valid on crushers with several eccentric throws.) The profile of mantle A and mantle B are very similar, but they sit at different position on the head center. The A mantle sits higher than the B mantle. The reason for needing more than one mantle is that the position of mantle changes with both eccentric throw and CSS. It is always advisable to have the mantle position inside the concave, otherwise there will be no wear on the bottom part of the mantle, this will create a poor wear profile which will have a negative effect on the crusher performance. For an illustration of a mantle sitting below the concave see Figure 2.
So, if the crusher has a bigger throw the mantle needs to be position further down so it has room to swing to reach the CSS. To position the mantel further down it needs to sit lower on the head center, otherwise the main shaft cannot be lowered enough. On the other hand, if the crusher has a smaller throw the mantle will need to swing a smaller distance and can be positioned higher. This is illustrated in Figure 4 where the throw has be reduced from biggest (Figure 3). The benefit of using an A mantle when possible is that it will give the crushing chamber a longer wear life.
We understand mantle and concave selection might seem to be complicated. So, to give a more hands on experience we have created an Excel dashboard, it can be downloaded from the same place as this paper. Give it a try and we are convinced you will think the A and B mantle selection is easy to understand, seeFigure 5
A cone crusher has one parameter that can be controlled on a continuous basis, namely CSS. CSS has a big impact on product gradation, and it is important to keep it under control. Since CSS is affected by wear on the mantle and concave it is important to measure and adjust frequently, in most cases daily. The CSS effect on gradation is as it becomes smaller the gradation gets finer, see Figure 6.
In addition to finer gradation the capacity will also decrease. If you remember that the size of the choke zone determines the capacity. When the mantel and concave is brought closer to each other to make the CSS smaller the size of the crushing zone becomes smaller, see Figure 7.
When adjusting the CSS the shape will also be affected. Research has shown that the best product shape is found at the same size as the CSS. Sizes larger and smaller than CSS will have gradually worse shape, see Figure 8.
When optimizing shape there is also a second parameter that should be considered, the reduction ratio. In general, better shape is generated when the reduction ratio is moderate. This could be good to know if the plant is operated in such a way that the crusher feed is altered. One could also improve the shape by increasing the reduction ratio (run at smaller CSS) in the previous crushing stage.
In addition to the CSS the eccentric throw is sometimes mentioned as an option for crusher optimization. In practice it is hard to utilize this on an already installed crusher for optimization of gradation or shape. The main effect eccentric throw has is adjusting the capacity and that is what it should mainly be used for. Eccentric throw will also affect both gradation and shape but the effect is small. To be able to measure the eccentric throws effect on those two parameters several steps of the eccentric bushing must be adjusted. Increasing the eccentric throw will mainly influence the finer part of the gradation curve. Bigger eccentric throw will increase the fines production and improve the particle shape. Shape and fines often go hand in hand, and this is no exception. So, comparing a crusher running on the smallest throw with a crusher running on the biggest throw you can except the crusher with the biggest throw to produce better shaped product and a higher percentage of fines.
The explanation is that with a small throw the material is crushed more gently in several small steps (many crushing zones), see Figure 10. The big throw will do the whole work in few crushing zones where the crushing pressure is relatively high, see Figure 11. As stated before, the effect is relatively small and the if you have an issue with excessive fines in an existing crusher it seldom make sense to reduce the eccentric throw to reduce the fines production. The capacity will drop to something like 50% before you see a clear effect in the percentage of fines produced.
So to make the process optimization efficient, use eccentric throw to adjust the capacity and the CSS to adjust the gradation. Trying to fine-tune gradation using eccentric throw is not to recommend, the effect of changing the eccentric bushing a step or two will not make a notable difference in gradation while you change the capacity with 10-20%.
Apart from keeping a close eye on the CSS during operation one should also make sure that the crusher is operated choke fed. Choke fed means that enough material is present in the crusher hopper to allow for material to fill the chamber. In terms of recommendations one should aim to cover the spider bearing house in fine and medium applications. On coarse applications it might sometimes be advisable to keep the level lower. In coarse applications a high level might cause bridging or hinder the material flow due to rocks interlocking.
Secondly it is also important to have an evenly distributed feed in the crushing chamber. Rocks of equal distribution should be present around the inlet of the crushing chamber. Short term, uneven distribution can be tolerated but if this is the statues quo it will cause problems. As mentioned before it is important to have rock of proper size fed to the crushing chamber. What happens with uneven distributions is that the material constantly will be too fine in parts of the chamber. The wear will therefore vary around the chamber, more in some parts less in others. This will make the concave loose its roundness and the CSS will vary around the chamber. In other words you are starting to loose control of the most important factor for productivity. This could eventually lead to so poor crusher performance that the crushing chamber must be replaced prematurely. This will cause both downtime and poor utilization of the mantle and concave.
Sometimes it is obvious that the crusher feed is misaligned or unevenly distributed. In those cases, something needs to be done. There are cases where the problem is more difficult to observe or quantify. One good way to evaluate is the thickness of the worn-out concave. Measure the thickness of the bottom part of the concave. The difference between thickest and thinnest must be significantly smaller than the crusher CSS. Hence a couple of millimeters out of roundness on a coarse chamber is not a big issue but on a fine chamber running on a small CSS a couple of millimeters in deviation on part of the chamber will affect the productivity. Especially if the crusher is running on minimum CSS where maximum reduction is needed.
In this paper the selection of crushing chamber was demonstrated. As mentioned, it is important to get this right because it has a significant effect on the crusher performance and plant productivity. The paper also stressed the importance of keeping an eye on the crusher during operation. It is important to know what to look for and to understand when problems need to be corrected and when it makes more sense to focus on something else. What we now would recommend you to do is to review your cone crushers. Do they have the correct crushing chambers? Are they fed properly? Do the worn-out wear parts look evenly worn? You should not be surprised to find issues that you can correct and thereby improve productivity.
DEM is used to understand breakage and operating performance of a cone crusher.The breakage model uses a replacement strategy and progeny size data from a DWT.There is strong variation in the breakage behaviour with height in the crusher.Larger particles jam in the compression zone prior to breakage and obstruct the flow.Trends in performance with material properties and operating parameters are found.
Discrete Element Method (DEM) simulation with non-round particles and including breakage has been used to understand the breakage behaviour and operating performance of an industrial scale cone crusher using a representative ore. The breakage model uses a replacement strategy and impact energy specific progeny size data from a Drop Weight Test (DWT). There is a strong variation in the breakage behaviour with height in the compression region as the differing profiles of the concave and mantle create five different regions with monotonically decreasing width and differing degrees of convergence between the surfaces. These control the rate of motion and the ability to load and break the particles, and determine whether high forces are generated via multi-particle stress chains or as single particle loading directly from the liner surfaces. The larger feed particles jam in the compression zone prior to breakage and cause observable obstruction to the flow of finer material and strong non-uniformity in the flow of product down the lower part of the mantle. Trends in the coarseness of product and changes in steady state throughput are identified with changes in material properties (rock breakage energy and friction coefficient) and crusher operating parameters (Closed Side Setting and crusher rotation rate).
Metso has introduced the new Nordberg HP900 Series cone crusher for the aggregate and mining markets, providing an upgrade to the HP800 cone crusher. Approximately 80 percent of the parts are compatible between the two technologies.
The HP900 comes with improved kinematics, raised pivot point and power increase which leads to a 15 percent capacity increase. A new lubrication system is included to help support the new performance level, while the tramp-release system allows the passage of tramp iron, minimizing production stoppages and protecting internal components.
The HP900 is delivered pre-assembled, pre-wired and factory tested. The equipment is packaged with a rubber-pad mounted subframe and guards allowing quick and safe setup with a compact footprint. These factors result in reducing installation time by 50 percent.
The crusher is also equipped with Metsos IC70C automation system to ensure optimum operating parameters. The IC70C is designed to be easy and simple to use. All information can be tracked using a single screen and features help and trouble-shooting options.Get in Touch with Mechanic