Forecasting is the identification of the most likely future time when major equipment components like engines, transmissions, pumps or conveyor drives may have to be replaced. It is not an automatic action in which, for example, a component is simply replaced after the accumulation of a certain number of operating hours or the passage of a number of weeks. This type of 'guesswork' can result in many 'perfectly good components' being replaced prematurely only to increase the rate of material consumption and its cost. Information extracted from Mining Maintenance Management Course. Courtesy of Paul D. Tomlingson

FORECASTING COMPONENT REPLACEMENTS How to Streamline Maintenance Planning and Scheduling   Forecasting is the identification of the most likely future time when major equipment components like engines, transmissions, pumps or conveyor drives may have to be replaced. It is not be an automatic action in which, for example, a component is simply replaced after the accumulation of a certain number of operating hours or the passage of so many weeks. This type of 'guesswork' can result in many 'perfectly good components' are being replaced prematurely only to increase the rate of material consumption and its cost.

Get More Performance Out Of Your Crusher impactor maintenanceThere’s an urban legend out there about the company whose maintenance crew mistakenly installed a new crusher with the rotor spinning backwards. It still worked! And you think you have issues? To get the most from your equipment investment, you need to put in the time. Yes, a crusher costs a bit more than your average automobile, but that doesn’t mean it’s maintenance-free. An automobile needs oil changes too, right? Performing regularly scheduled maintenance on impact crushers is crucial for guaranteeing day-to-day reliability and optimum product output. Did you know you can boost output and quality by doing just a little bit more? Even daily cleanups and inspections can increase service life. It’s a no-brainer, though possibly easier said than done. Here are some steps and practices to incorporate in your ongoing operations and maintenance. Beginning with maintenance team education, parts logs, and general maintenance record keeping, plus troubleshooting, these guidelines will help your crusher go the distance. Training: Proper training for consistent maintenance is one of the most fundamental requirements for successful, reliable production. Begin with the crusher’s operation and maintenance manual. Incorporate the manual’s suggested routine maintenance schedule into the maintenance team’s duties. Appoint a “lead person” for each crusher as the go-to for that machine. This person is the historian for the unique operational adjustments the producer has incorporated for raw feed and product requirements. Daily log (document the following every 8 hours): Amperage draw: See if it changes from day to day. If amperage is exceeding normal levels, it could be a signal of bearing problems, loose belts, or general feed issues. Coast-down time: You’re going to need to know (and log) how long it takes the machine to come to a complete stop after shutdown. Here’s why: If the time starts to shorten, this could indicate a bearing problem. Oil pressure: You’ll want to record performance in a variety of operating conditions. This will allow you to identify trends and help to detect problems before they cause costly damage or downtime. Daily maintenance (every 8 hours): Check oil level, sight glass, grease appearance, and other lubrication schedules. Check high temperature or low hydraulic pressure indicators and switches. Check wear parts. Tighten bolts. Inspect belts. Remove dirt and debris from crusher frame surfaces and areas around the machine. Check intake/discharge chutes for any obstructions and/or build up. Check alarms. If electrical changes are made or programs are altered in automated systems, verify that all alarms and interlocks function properly. Don’t be afraid to replace switches or timers that appear damaged or are in poor condition. This is more economical than a major overhaul, but never disable or alter any alarms or interlocks! Lubrication: Completely drain and thoroughly clean out the inside of the oil tank (if you have one) to eliminate any contaminants before refilling. Find contaminant sources. Contaminants such as dust particles and water can get in where oil leaks out. Inspect hydraulic systems and tag any leaks for corrective action on the very next maintenance cycle. Use the proper grade of oil. Use the proper specification of filters. Keep the oil breathers clean. Understand grease versus oil lubrication. Grease requires less-intensive maintenance than that of oil-lubricated systems. Automatic oil lubrication systems or sealed cartridge bearings are for higher speed crushers like vertical shaft impactors, air swept fine grinders, or high-speed cage mills. Most horizontal shaft impactors, hammer mills, and cage mill applications are below 1,000 rpm and grease is sufficient. Maintain a scheduled oil sampling program. By creating a baseline of normal wear, it helps indicate when abnormal wear or contamination is occurring. The exact condition of a mechanical assembly is reflected in the oil. Belts: Inspect V-belt drives for damaged belts or loose belt tension. By replacing cracked, glazed, torn, or separated belts, plus maintaining proper belt tension, you’ll optimize your plant’s performance. Wear parts: Don’t overextend wear parts. Avoid running them so long that they become too worn. You may find that you can no longer rotate breaker bars or interchange wear plates to lower wear areas — and now, you’ve lost half of the wear. Guards: Rubber and chain curtains located in the feed and discharge openings of the crusher are subject to wear and tear. Since they are a first line of protection, it’s important to inspect them regularly and to establish a schedule of regular maintenance. Electrical: When (or if) electrical changes are made, you’ll need to verify that all alarms and interlocks still properly function. Same goes for programs when altered in automated systems. Always check with the manufacturer before making any modifications. Spares recommendation: Keep the recommended spares on hand and order replacements as soon as they are used. A list of recommended spares may be included with your equipment operations manual. If not, contact the manufacturer for recommendations. Update your equipment: All equipment evolves, and the recommended manufacturer upgrades are a good investment for increased life and better crusher performance. Check with the manufacturer for any possible updates. Unapproved modifications: Manufacturer design engineers have considerable field experience, which helps them as they calculate the design and perform prototype testing. Their engineering tasks include calculating bearing loads and bearing clearances. They’ve also worked to maximize throughput by establishing the most efficient speed and setting combinations to optimize impact on the material undergoing reduction. So when plant personnel suggest modifications that alter the intended design, these changes will more than likely hurt the purpose of the original design. As a result, you’ll have a less productive and reliable crusher due to potential damage and overload. Since the manufacturer has a vested interest in how well the crusher performs, contact them before making any modifications Cage Mill Operation and Maintenance Requirements for optimum production and wear part utilization include the following: sleeve wear patterns cage wear pattern identification To increase multi-cage sleeve life, cage rotation should be reversed regularly, if possible. (Some cage mills can be reversed, while others cannot.) By reversing the cage direction, sleeves will be worn from both sides, thus extending wear life. Wear parts: Index and or replace sleeves periodically. Inspect or replace hopper ring and shaft protector, if needed. Cage rebuilding is an option. Bearings: Follow the manufacturer’s recommended specifications and schedule for lubrications, temperature, and vibration ranges of spherical roller bearings in pillow block housings. Horizontal Shaft Impactor Operation and Maintenance Variables affecting product gradation include the following: Rotor speed – Higher rotor speeds produce finer product output.Breaker bar wear & new edges crush finerBreaker bar changes. Apron gap settings – Closer gaps retain the feed longer producing a finer product. Breaker bar wear – Regular inspection and turning will lower operating costs. Throughput (tons per hour) – Overfeeding a crusher can make the output more coarse, but it also causes a number of wear and longevity issues making overfeeding a major concern to avoid. Moisture – Moisture cushions the impact, producing a coarser product. Apron wear – Worn plates can be replaced or moved to areas of lower wear. Spring bridge operation – Spring set height is critical to maintain proper operation of spring bridges. Spring bridges return the aprons to their original positions after an overload situation. The use of altered or non-specified springs can cause equipment damage or catastrophic failure. Requirements for optimum production and wear part utilization include the following: Protect inlet and outlet. Restrict maximum feed size. Maintain feed rate within allowable limits. Check rotor rotation. Use metal detection (required). Check for wear. Follow recommended breaker bar rotation setting sequence. Check rotor breaker bar, wedge, and stop block or jack screws. Check liners and breaker plates. Vertical Shaft Impactor Operation And Maintenance The vertical shaft impactor uses high rotor speeds (1,000 to 3,000 rpm) to apply high energies to the material, and since Energy + Material = Size Reduction, it can create sand from 2-inch feed. Requirements for optimum production and wear part utilization include the following: optimized parts in rotor tube Limit feed size. Use metal detection (required). Observe any vibrations with the use of continuously monitored vibration sensors. Listen to the equipment, if something sounds unusual, shut down and inspect. Limit recirculating product in a closed system. If using water for dust suppression, introduce it into the discharge area if possible. Introducing water in the intake will increase wear. Place weight match shoes opposite one another. The image above shows rotor tubes indexed 90 degrees providing a new wear surface. Wear parts include the following:recommended parts for vertical shaft impactors Shoes and tubes Anvil ring or other inserts Housing liners Rotor table liners and assembly Spares recommendation: Shoes (one complete set) Table liner Anvils (one complete set) Discharge plate The spare parts inventory shown above is recommended for vertical shaft impactors. Hammer Mill operation and Maintenance Up running hammer mills combine impact and shear to reduce material. Down running hammer mills primarily use shear by immediately taking feed to the screen or grate bars where hammers shear the material, until it passes through the openings. Requirements for optimum production and wear part utilization include the following: Lubricate bearings regularly. Regularly inspection (unclamp or unbolt front upper half housing for access to screens and hammers) liners, hammers, hammer bolts, rotor discs, grate bars, and screens. Spares recommendation: Hammers Screens Liners Grinding plate Summary A partnership begins between the manufacturer and the customer when the crusher is installed in the field. The manufacturer needs the customer’s help as much as the customer needs the manufacturer’s help to achieve the highest performance possible. Maintenance service after the sale, although mentioned last, is a central part of crusher system performance. And just in case, the manufacturer will have the people and the parts available 24/7 to assist with any problems. Regardless of the field application, the training of personnel is key to successfully and optimally operating equipment. For the size-reduction industry, crusher maintenance problems are mostly related to inadequate training. This exists at plants both large and small. The most effective education is a current and ongoing program for crews — and that’s what will result in legendary performance.

New plant, automation system double operation’s production capacity By Loretta Sorensen| November 10, 2017 Four generations of the Duff family have overseen quarry operations for the past 67 years at Duff Quarry Inc. in Huntsville, Ohio. Among the reasons for their long-term success is a focus on high-quality, economic throughput. “That’s one of our focal points,” says Ross Duff, vice president. “For the past 10 years, automation has allowed us to maximize safety, improve ease of maintenance and have direct oversight of material quality.” Photo courtesy of Duff Quarry Duff Quarry was bare farm ground when the late C.E. Duff purchased it in 1950. Its abundant limestone deposit runs about 400 ft. deep and covers around 400 acres. Today, with three locations, Duff Quarry includes Ohio Ready Mix and Mr. Concrete Builders Supply, employing more than 60 people in Huntsville, Russells Point and Bellefontaine. Customers come from within a 25-mile radius of Huntsville. New era The Huntsville quarry contains bluish-gray dolomitic limestone, which is ideal for construction materials like concrete and asphalt production, the company says. Upper layers of the quarry’s limestone deposit have a high magnesium content, giving the stone a reddish hue. Lower limestone layers, in laminated sheets, are dark gray. The quarry’s limestone is crushed and used in a number of construction projects, including private and business drives in the area. Duff Quarry customers also purchase a variety of crushed limestone products, riprap, concrete sand, mason sand and gravel. In 2005, when Duff Quarry was responding to increased product demand, it purchased a new limestone crushing plant from Stedman Machine Co. At the time, Duff was updating the plant it had used since 1956, seeking equipment that would offer flexibility with product size. The Duff family first learned about Stedman around 1956, when it purchased a Stedman 48-in. four-row cage mill to process agricultural lime at its old quarry. In 1994, Duff purchased a Stedman Mega-Slam crusher for a different location because the company believed it was a superior crusher with its portable plant. Over two and a half years, a Stedman affiliate, Innovative Processing Solutions, designed and fabricated the new automated system, which utilized Stedman’s 5460 Mega-Slam and 6460 Grand-Slam size reduction impact crushers. Innovative Processing Solutions specializes in custom solutions for bulk material handling systems, using equipment from Stedman and other manufacturers to create a variety of systems. The extended system design timeframe gave the Duff family the opportunity to develop a system that can serve them for many years. “We bought the plant in 2005, installed it ourselves and completed construction in 2007,” Ross says. “It was more than 95 truckloads of steel. Apex Engineering set up our automation. The plant uses twin Stedman impact crushers, a Deister grizzly feeder, scalping screen and twin finish screens.” Twelve employees kept the old plant running while the new plant was designed and installed. Prior to installing the new system, the quarry’s annual processing average was about 600,000 tons of limestone. With the new system, production averages 1.5 million tpy when running at full capacity. Customized crushing From left: Plant Operator Jason Beecraft, Mine Foreman Bill Page, President J David Duff and Vice President Ross Duff. Photos courtesy of Duff Quarry The quarry’s automated system includes a fiber linked A. B. Rockwell PLC system run by redundant Windows-based computer control rooms. Quarry operators manage the automation by utilizing an application that runs through two iPads. The system is set up so only one iPad can make system changes at any one time. The plant operator can access the automation system from anywhere on the mine site. “When we designed our plant, we wanted to avoid having our plant operator watch quarry activities from a remote control room,” Ross says. “Using the iPad allows the plant operator to have direct oversight of material quality and make immediate changes as necessary. “It also eliminated the need to contact the person in the main control center,” Ross continues. “A delayed response is not always the safest way to operate. If the plant operator is right there they can stop or start the plant and inspect any equipment to identify maintenance needs.” The iPad used to control the system uses a WiFi signal generated by a router installed in the quarry. Signal strength can vary but is always strong enough to make iPad use viable, Ross says. “You could even control our plant from an iPhone,” he adds. “Because of the phone’s screen size, that isn’t realistic. But in an emergency I could shut the plant down with my phone.” Initial concerns about dust affecting iPad operation were allayed because the iPad has no vent holes or keyboards that could collect dust from the quarry. “No proprietary software is loaded on the iPad,” Ross says. “It’s basically a touchscreen remote for the main control computer that runs Windows.” Although Duff Quarry’s automated system can be connected to the Internet for updates and other resources, it’s only connected for short periods of time to address a specific need. “Our primary network is an intranet,” Ross says. “We avoid Internet connections as much as possible to reduce hacking potential. Programmers can access our system remotely to adjust it, but we’re very cautious with that.” Precise products Stedman’s Mega-Slam is a primary impact horizontal shaft impactor that effectively handles large feed sizes. The machine is built to handle thousands of materials, ores and chemicals in wet and dry applications. Mega-Slam’s design offers safe and easy access for breaker bar replacement and access to all other areas of the crushing chamber, according to the company. The machine’s front opening feature eliminates the need for a crane. The Grand-Slam secondary impact crusher, meanwhile, is built to handle the same type of materials as the Mega-Slam. Through design simplicity, employees have safe and easy access to breaker bars and all other crushing chamber areas. The twin impact crushers give Duff Quarry the cube-shaped rock that provides greater psi strength when used in concrete mixes, which represents a significant portion of their business. Integrated with an automated variable frequency system, the grizzly feeder provides the variable speeds that allow for maximum throughput without overloading the crushing plant. “Our plant has amperage and motion sensors on every conveyor,” Ross says. “Belt scales directly control throughput on the feeder so production runs at maximum speed without overloading belts. We also use tramp metal detection and pneumatically controlled discharge gates to dump material. In the event that metal makes its way into the plant, our automation system empties all belts to protect the crushers.” Quarry-wide benefits Photo courtesy of Duff Quarry The dolomitic limestone at Duff Quarry is desirable for construction materials like asphalt and concrete. With its automated system, Duff Quarry can also manage electricity meter spikes because the system will automatically cut feed rate if production exceeds 840 tons for more than five seconds. Each crushing plant conveyor is equipped with terminal strips wired to communicate production information to one main processor, allowing one staff member to monitor conveyor performance. All feeders and conveyor operations data are also recorded for use in evaluating the system’s overall performance. The new plant system allows Duff Quarry to crush rock in a variety of weather conditions, including heavy rain. Pumps and drain lines under the plant ensure that flooding cannot occur. The Duff family expected to reduce maintenance issues by at least 50 percent with the new plant because automated data management provides evidence of equipment issues well ahead of a breakdown. Since the plant can now be operated with just two staff members, the company no longer shuts production down for lunch hours. Adjusting product size takes just minutes, and the same conveyor can be used to handle different product sizes. Doubling output Overall, Duff Quarry more than doubled production capacity with its automated system and new plant. “We also have brilliant staff operating the plant,” Ross says. “Bill Page, a foreman here for more than 40 years, is a great example of that.” Over the years, Page tried different methods to prevent screen media clogging. He never found an effective product or method, so Page developed his own: the Blinding Buster. “We wanted to ensure our material quality on the finish end was automated, too,” Ross says. “Bill patented an invention to eliminate screen blinding. Every screen media, by nature, will blind, given the right conditions. The Blinding Buster continuously sweeps blinding off finish screens while we’re in production.” The Blinding Buster consists of two major components: the control assembly and motor assembly. The control assembly wires are designed to connect to the normally open auxiliary contact of a screen’s magnetic starter. The screen can be set up to start manually if the motor start isn’t available. The motor assembly includes a standard 20-ft., 3/8-in. chain that can be cut to any length or extended to accommodate all screen sizes. Installing the Blinding Buster takes a 2-in. black steel pipe mounted level approximately 6 in. above the screen opening. The pipe has to be affixed so it doesn’t vibrate with the screen. “The Blinding Buster allows us to screen in subpar conditions when we normally wouldn’t be able to,” Ross says. “We are also able to dry screen finish products without washing. We’re so happy with this product that we’ve made it available to other quarry producers.” Loretta Sorensen is a freelance writer in Yankton, South Dakota. She produces material on a variety of topics, serves as a ghostwriter and has authored her own books.

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.

The purpose of this paper is to review a case study of a successful energy project at the ArcelorMittal Burns Harbor facility involving the addition of five new adjustable frequency drives (AFDs) used to regulate flow of the high-volume water spray system for the runout table (ROT). The paper will outline 1) processes used in justifying new technology updates, 2) mill alignment with the serving electric utility to leverage energy credits, 3) equipment selection and installation and 4) metrics used to demonstrate the project delivered the desired payback.

Link-Belt is the industry standard for screw conveyors, feeders and components. We make a complete line of screw feeders, conveyor screws, troughs, trough ends, hangers, bearings, shafts, seals and drives.

Syntron Material Handling is the answer for all you Coal Mining Material Handling needs.

Van der Graaf is a leading designer and manufacturer of specially engineered drum motors. Built to endure the demands of the bulk handling industry – from ship loading, to power generation, to surface and underground mining. Van der Graaf products are manufactured and marketed worldwide through a respected international network of distributors. As the leading global supplier of conveyor belt drives, Van der Graaf has proven to be highly intuitive in projecting and reacting to changing market demands. The Extreme Duty Series offers a conveyor drive in which all components are housed internally. This advanced design eliminates the need for external features including the motor, gearbox, sprockets, chain, chain guard, and pillow block bearings, making it ideal for the harshest of environments. The Van der Graaf Extreme Duty Mining Series incorporates the benefits of a tried and tested drum motor with an increase in power and capacity. This durable design is entirely sealed from the most challenging work environments, providing a completely reliable, less complex, and virtually maintenance-free belt drive solution.

Drum Motors for Mining and Aggregate Applications Requiring High Power Conveyor Drives The rugged design of the Van der Graaf drum motor is ideal for the harsh and abrasive environmental conditions of the mining and aggregate handling industry. The drum motor encloses all moving parts within an oil bath that prevents dust and grit from wearing out key components. The benefit of this design eliminates the maintenance required on conventional exposed conveyor drives. • Engineered for Harsh Abrasive Environments • Lower Energy Costs • No Maintenance • Up to 300 HP

Pinetree Power, a subsidiary of GDF Suez Energy North America, in Fitchburg, MA, upgraded their conveyor drives to Van der Graaf Drum Motors. This upgrade allowed them to free up between 300 and 500 homes worth of electricity, increasing their revenue, while lowering operating and maintenance costs.

Adjustable frequency drive offering from Eaton improved reliability and enhanced safety with a small physical footprint. Estimated monthly energy savings up to $45,000, as well as an integrated design contributing to reductions in material costs and timely delivery minimizing plant downtime.

AZFAB has developed a solution to one of a plants operator’s biggest problems…WATER. In the industry, water has become one of our most important commodities. It often takes months to reclaim water from settling ponds. In addition, there is a significant loss of this precious resource in a traditional pond system. AZFAB Thickeners will help you face those challenges and lower your operating costs. Making efficient use of flocculants and effective use of settling zones, AZFAB Thickener-Clarifier can significantly reduce the size of settling ponds and can do so with minimal power consumption and chemical cost. The AZFAB system can return 90% of wash water back into the plant’s operation within 30 minutes. Tanks are 16 feet high and range in diameter from 30 to 85 feet. The systems can handle 2,000 to 18,000 gallons per minute and can be designed to fit the plant’s exact needs. All units come equipped with low drag rakes, hydraulic drives, and PLC control. The system is a bolt together design, and assembled in USA.

AZFAB has developed a solution to one of a plants operator’s biggest problems…WATER. In the industry, water has become one of our most important commodities. It often takes months to reclaim water from settling ponds. In addition, there is a significant loss of this precious resource in a traditional pond system. AZFAB Thickeners will help you face those challenges and lower your operating costs. Making efficient use of flocculants and effective use of settling zones, AZFAB Thickener-Clarifier can significantly reduce the size of settling ponds and can do so with minimal power consumption and chemical cost. The AZFAB system can return 90% of wash water back into the plant’s operation within 30 minutes. Tanks are 16 feet high and range in diameter from 30 to 85 feet. The systems can handle 2,000 to 18,000 gallons per minute and can be designed to fit the plant’s exact needs. All units come equipped with low drag rakes, hydraulic drives, and PLC control. The system is a bolt together design, and assembled in USA.