Telsmith provides a full range of integrated processing equipment to the aggregate, mining, industrial, and recycling industries with cone crushers, jaw crushers, vibrating equipment, portable plants, track plants, as well as full-scale modular processing facilities. 

All You Need To Know About Cage Mills Cage Mills have a high ratio of size reduction after a single pass through the cages. Here's why, and how. Hands down one of the most versatile size reduction machines and one of the hardest working is the cage mill. There are several varieties of cage mills, but their similarities are more numerous than their differences. They all are internally fed impactors that can crush, grind or pulverize many different materials to specified degrees of fineness. History By 1900, Nathan Stedman had built more than one hundred cage mills designed exclusively to crush coal. Soon other applications were discovered, leading to the increased use of cage mills for crushing such products as chemicals, clay and fertilizer materials. Multiple-row cage mills – two-, four- and six-row -- were commonplace. It was not until the 1930s that the true value of cage mills in the production of agricultural limestone and the crushing and beneficiation of stone and gravel was realized. Cage Mill Pulverizers The cage mill was so popular the Stedman Machine Company became part of farming vernacular -- farmers began referring to agricultural limestone as “Stedman Lime” due to the cage mill's unique capability to create the proper material fineness in just one pass through the crusher. Single-row cage mills were used extensively in the construction of the pioneered Pennsylvania Turnpike, primarily for the beneficiation of aggregates. Beneficiation is an elementary process, but it still is one of the most widely practiced applications of single-row cage mills. Gravel is passed through the mill and the softer, undesirable particles; -- breaking more readily than the harder ones; -- are screened or washed away, leaving a hard, high-quality aggregate. Versatility New uses are constantly being discovered for these versatile workhorses, but the nature of cage mills is such that improvements in them tend to be gradual and evolutionary instead of dramatic and revolutionary. The cage mill can be applied to effectively crush, grind and pulverize a broad array of abrasive and non-abrasive materials, including wet sticky types. The latest technology incorporated in these high-efficiency design mills insures greater crushing capacities, finer grinds and cleaner, safer operation. Fundamentally, cage mills are crushers capable of reducing or disintegrating many kinds of materials to small pieces. They reduce materials solely by impact and range in size from as small as 18 inches to as much as 72 inches in diameter. However, custom units may range as high as 96 inches in diameter. In general, the larger the mill, the lower the cost of operation when measured against tons of output. Operation Cage Mill Size Reduction Equipment A typical cage mill has only one part that moves - the rotor assembly. The material to be crushed is fed into the center of the rotor, or cage, through an intake hopper. The massive bars of the spinning cage aligned in rows strike the material and smash it into particles. The particles are then thrown against subsequent rows, other particles and the cage housing where they impact against breaker plates. Every impact - against cage bar, breaker plate or another particle - tends to reduce the original matter further, into more numerous and smaller pieces. By the time the material finally escapes from the cage mill, it has been thoroughly crushed. The major difference compared to other size reduction methods is the absence of close clearances between the crushing part and the breaker plates, allowing for less maintenance and higher efficiency of the machine. Also, they do not require grate bars as the principal source of impact in the cage mill are the pins of the revolving cages. Impact crushing, particularly impact crushing that uses the most suitable cage mill available, has a number of advantages over compression crushing. Cage mills produce a more cubical product of consistently high quality and they are capable of a very high ratio reduction. There is no decrease in quality of the product even after long periods of operation. Cage mills represent a lower initial investment than most other types of crushing equipment and maintenance is easy and inexpensive to perform. Application Cage Mill Manufacturer The wisest and most effective use of cage mills depends on a proper understanding of them, of how they are made and what they will and will not do. Multi-row mills typically consist of an even number of cages: two, four or six. The cages are arranged concentrically, with each row spinning in the opposite direction from that of the row adjacent to it. Two motors are required. They are mounted on opposing sides of the mill, where they turn in opposite directions. One, two or three rows may be mounted on each shaft. A multi-row cage mill utilizes multiple stages of selective impact reduction. The material to be reduced is fed into the center of the innermost cage, where it is struck by the massive spinning pins and distributed 360 degrees around the cage. Centrifugal force and the impact of the pins causes the material, now reduced to smaller pieces, to pass through the cage into the pins of the next row, which is spinning in the opposite direction. The farther away from the center cage the particles travel, the more their impact velocity is increased. In the process of being thrown from row to row the particles also strike each other. They finally are thrown against tough breaker plates that line the inside of the housing. After many violent strikes against the pins, the breaker plates and each other, the much-reduced particles are caught by the outer housing and allowed to drop through the discharge at the bottom of the housing. Size Control Properly presetting the speed of the cages allows the succeeding rows, moving from the innermost outward, to act principally on the particles that have not yet been reduced to the desired size. Particles that have been crushed sufficiently tend to pass through the subsequent rows without being materially affected. Thus, over crushing or under crushing is effectively controlled by adjusting the speed of the cages. All cage mills are fed internally - - the material to be crushed is dropped into a hopper, from which it travels by chute into the center of the innermost row. It falls from the chute onto the spinning pins of the cage, which strike the falling pieces of feed and explode them into many smaller pieces. The particles are propelled by centrifugal force from the innermost cage into the pins of the adjacent row, which is spinning in the opposite direction. Cage Mills for Aggregates Particles that are still too large are struck by the pins of the second row and reduced further. The reduction process continues through any additional rows that may be part of the machine. The impact velocity of the particles increases as the centrifugal force carries them outward from one cage to the next until they finally strike the mill housing and drop toward the large discharge opening at the bottom of the housing. Controlling the speed at which the cages revolve allows the operator to control the amount of reduction that takes place. That is, if the speed is properly preset and controlled, the material will be reduced to its desired size at some point during its trip through the cage mill and then virtually no further reduction will have to take place. The selective impact crushing that is a characteristic of cage mills minimizes the amount of oversize and undersize particles to be found in the finished product. The design of the cages controls the path that the material will flow through the machine. This makes it possible to concentrate the wear on the pins, which are made of very hard alloys to give maximum possible service before they have to be replaced.

How Much Does It Cost To Operate a Crusher? By Chris Nawalaniec Crushing equipment is the heart of an industrial material-processing system. The size reduction choice you make will have a profound impact on the profitability of your business. When the right choice is made, you should expect many years of profitable operation. How do you make the right crusher choice? Crushers are not glamourous. They are brute force workhorses and what they do is simple, really. Size-reduction equipment in all forms is adding energy to a material to make big pieces smaller. Simple, right? Cost versus Value What does it cost or what is it worth? Producers need to keep that simple equation in mind. We all have to keep our eye on the ball and stay focused on profitability. What are Crushing Costs? Capital acquisition cost Base machine Structures and chutes Motors, drives, guards Energy consumption per unit produced Electricity Compressed air Wear parts cost Normal maintenance Planned downtime Lubrication costs Oil Grease Major repairs Infrequent maintenance Unplanned downtime Labor Normal maintenance Special or unique tools required When the above costs are all accounted for, they are used to quantify the production costs related to size reduction and are expressed in cost per unit of measure production. For example, $0.50 per tph. What Does Value Mean? There are always opportunities to buy a machine at a lower upfront cost. This usually translates into paying higher operating costs over the life of the equipment. Higher service labor cost. Higher wear parts costs. Higher energy costs. Often there is a justifiable case to spend additional capital dollars for the better machine. When evaluating crushing equipment suppliers, crusher manufacturers should quantify both costs: purchase price and operating costs. Before you purchase, ask for reference customers to visit. Selecting Equipment Why are there so many types of equipment? Our team brainstormed this question, and we came up with more than 50 tools or machines that are used for size reduction. What we are addressing here is industrial size reduction of dry, solid materials, which are grown, mined or chemically synthesized, and need to have a physical dimension alteration to be put to use. Customers are asked five questions to begin the equipment selection process. What is the material? What is the moisture content? What is the maximum size going into the machine? What is the size range desired after crushing? What is the desired production rate of finished product? When it’s time to dive a bit deeper to define the problem, we ask some additional questions. How long do you expect to operate the plant? Are you looking at mobile, skid-mounted or fixed installation? Are there electrical limitations or special power requirements at the plant site? Is the system open or closed circuit? Do we need to consider future expansion plans now? The variables above all affect your costs. Let’s take the first question as an example. How long do you plan to operate? There are times when mines reserves, stockpiles, permits, project contract terms affect expected life. If a project is limited by any factor, then “good enough” could be the best choice. As long as the equipment is safe and there are machine wear parts and service available, then going “cheap” may be the best choice. Another factor to consider with low-cost is limited post-sale assistance if there is some process change or major equipment problem. You don’t want to be hung out to dry. Aggregate producers typically expect to be running and profitable for many years. Always buy a crusher from an established company, develop a relationship, and expect ongoing service and personal contact. Ask before you buy about how they approach post-sale parts sales and service. Ask the company quoting how they intend to offer service for their crusher. How many field service people do they have? Are they local, regional or too far away? Not having responsive suppliers will have a significant impact on your plant profitability. Summary Investing in the best size reduction equipment for your specific needs is a big decision. The above should give you a lot to think about so equipment solutions can be objectively analyzed. Chris Nawalaniec is vice president of sales and marketing at Stedman Machine Co.

Teamwork Helps Integrate Design, Manufacture and Installation of Size- Reduction Systems By Eric Marcotte, Inside Sales Manager, Stedman Machine Company Designing and deploying size-reduction systems takes experience. Many people can collect and install some of the pieces they feel are needed to create a working system, but experience with the interrelationships between components is harder to find. And to ensure safety and performance, crushing, screening, storage and handling systems need to be professionally engineered. A system is always more than just a collection of parts; they must work together whether it’s a properly designed chute or an elaborate processing plant. Retrofitting new crushers, conveyors, screens or other pieces of equipment is also not always an easy process. Even if drawings and specifications no longer exist, plant designers need to make sense of what is there and know what it takes to make new pieces fit in an existing puzzle. If continuing production during the upgrade is required, system bottlenecks will need to be prevented. For example, raw material or finished product stockpiles may be required to keep downtime to a minimum. Also, access and space requirements need to be confirmed and double-checked. First - Assemble a Team Engineering and expertise in a variety of areas are required to develop size reduction systems, including: crushing, screening, structures, conveyors, chutes, hoppers, dust collection and storage, whether for a small equipment retrofit or a large turnkey facility. CAD and process design software applications are must have. Limit multiple layers of personnel. Work directly with the engineers and personnel to select the equipment and design the system. Project management, installation, scheduling and tracking experience will be needed. Be sure supervisors and installers are MSHA trained and have experience in fieldwork. Second - Process Design While most projects present new challenges, a widely experienced team will bring in ideas from other industries. Typical projects involve the following processes and types of equipment. industrial crusher Load out and material receiving This can be a feed hopper with an apron feeder, belt feeder, vibratory or screw feeder, truck dump or railcar unloading system. Bulk material transportation Designing, building or procuring belt conveyors, stackers, apron conveyors, screw conveyors, and pneumatic handling conveyors. Crushing Crushing is the basic building block of a size-reduction system. Experience with a large range of crushing equipment offers many solutions. Properly feeding material into the crusher greatly increases its efficiency, contributes to even wear and maximizes wear metal costs. Bulk material storage Specifying, providing and installing a range of silos, hoppers or other bulk storage solutions. aggregate crusher Screening Experience with many screening manufacturers to include the right screening solution into the system. Dust Collection Including the proper dust collector and dust collection system is a key component to allow a crushing system to work properly. Experience with many dust collection vendors will facilitate properly sizing, connecting and installing the best dust-collection system solution. Controls and Electrical Components To make sure that all components of a system work together, work with control system engineers, panel builders and electrical contractors to create a working, integrated system. Buildings, Foundations and Structure Design, procurement and specifications for buildings, foundations and structures for the equipment supplied on any system. Third - How to Do It Every project has a different set of circumstances that are unique to it. Try to follow a simple checklist to ensure the best possible solutions to the problems. Initial project team meeting. Crusher and screening testing as required. Define required scope for the system. Create preliminary concepts and drawings. Review with operators and supervisors. After receiving feedback, fine-tune the drawings, concepts and put forth a detailed proposal. Set up kick off meetings as required. Proceed with the purchase of major components. Proceed with a detailed system arrangement. Detail major assemblies. Assemblies put out for detail drawing creation. Drawings are self-checked and then crosschecked for accuracy. Assemblies are re-entered into system layout from detail assemblies to verify fit. Approval drawings sent out as required. Vendor drawings checked and approved. Items checked as they are received. Work with vendors and shipping to verify shipment accuracy. Pictures are taken of all shipments for record purposes. Installation supervisor works with install crew to identify, locate and erect items as needed. As installation finish date nears, begin check of motor rotations, sensors etc. Final customer acceptance – formal reviews to finalize “punch list,” follow up items and document the system is performing as specified. Example - Typical Quarry Expansion A limestone quarry running since the 1950s and producing 500,000 tons per year wanted to increase yearly production capacity up to 1.5 million tons with a new automated plant. The new design needed to have the capability to stockpile hundreds of thousands of tons of finished product. The focus was on creating a state-of-the-art plant with designed-in flexibility to do different product sizing. The automated plant needed to have the ability to run production all day as well as to be able to change the product sizes within 10 minutes. The design and fabrication of a new plant may take up to two years to complete as each idea is considered and "wish lists" are sorted out. You don’t want to come back and say we should have done this or done that. Get the very best of everything you can get into the plant for longevity. The project will include numerous conveyors, sensors, controls, vibrating screens, feeders and other equipment. size reduction machine Installed electronics and control systems feed a programmable logic controller. Each conveyor at the plant is equipped with terminal strips that are all wired to communicate information to one main processor, bringing all of the information together in one place to make it easy to operate. All of the feeders and conveyors are monitored to collect all of the information required to operate the plant. With the ability to monitor the speed of the conveyors and feeders, the quarry can keep an eye on production and troubleshoot maintenance issues. The reason for having an automated control system is that if something goes wrong on one of the conveyors, you’ll see it fast enough to prevent a catastrophe that might require digging out a conveyor. If something does go wrong, the computer can take over and begin dropping conveyors, discharging material and shut the feeder down. Since the quarry can now monitor the conveyors moving, the speeds and the tons per hour, limitations can be set to help catch problems before they become too serious. If something is going wrong, say conveyor 2A is slowing down, you can put limits on how much you want to allow it to slow down before the feeder is paused and then limit how long that feeder stays paused. In the end, the quarry was able to more than double their production capacity with the help of the automated plant. The plant was built, delivered and installed as planned with no problems. This is an ideal situation if a quarry is sitting on huge reserves of limestone and plans to operate the crushing plant well into the future. Projects such as this are successful when the customer’s needs are defined and understood, and the project team – including the customer and all supplier partners work to accomplish the project goals.

Stedman Size Reduction Test Lab, Testing Materials From A-Z, Featuring Full-Size Crushing Equipment for Dependable Results. Stedman's unique test lab assures you're buying the right equipment for the job. Our highly-trained and experienced technicians will test your materials on full-size equipment. The Stedman testing program gives you the information you need to select the right crushing and size reduction equipment. Grand Slam™ Impactor, The Stedman 30" x 30" Grand Slam tests secondary and tertiary applications. Gap settings and rotor speeds for specific particle size gradation can be determined. H-Series™ Multi-Row Cage Mill Pulverizer, A wide variety of 2, 4 and 6 row cage designs with a complete range of sleeve/pin spacings. V-Slam™ Impactor, Designed for size reduction of minerals, ores and chemicals. Micro-Max™ Fine Grind Air Swept Mill , Screenless mill capable of producing a wide range of particle sizes. Liquid injection ports standard for grinding heat sensitive materials, or by adding heat capable of grinding and drying in one pass. Aurora™ Single or Dual Rotor Crusher , Designed for higher throughput and smaller particles. Ideal when delumping for pneumatic conveying or unloading. Complete Analysis From Experienced Professionals , The quality data produced from the test of your material helps you estimate operating costs from power consump­tion to wear parts. The written technical report provided to you includes: • Moisture content analysis • Gilson screening of raw feed particle size distribution • Product particle size distribution • Bulk density analysis • Abrasion test results • Estimated metal replacement costs • Horsepower consumption