MINExpo 2012; 1,890 exhibits filled Las Vegas Convention Center [Mining Engineering]
(Mining Engineering Via Acquire Media NewsEdge) MINExpo is about big, and most companies were rolling out their biggest products on the show floor this year.
Efficiency, flexibility and size were some of the buzzwords at this year's MINExpo. As ore grade decreases, machines must be able to process more material in less time to maintain profits. Pressure is on to produce more with less in less time, and the companies that service mines aim to be there the products they need. Companies were rolling out some of their biggest products yet, with higher capacities, more throughput and faster process times.
Metso introduced a new line of high-pressure grinding rolls, the HRC.This HPGR features two crushing tires, one fixed, one floating, which enable the machine to reduce energy costs downstream through microcracking the ore. The advantages of the new HPGR include a patented arch frame that maintains an even gap between the two rolls, preventing skewing. They also allow the use of flanges instead of cheek plates, promoting even wear on the tires and studs and eliminating the bathtub effect. The HRC product line can be used as tertiary crushers, quaternary crushers or pebble crushers and comes in 1Ü different sizes.
Metso also introduced the Poly-Met Megaliner for large-diameter mills. This new liner is faster, easier and safer to replace; it is lighter, and only one person is needed inside the mill to position the liner during replacement. In addition, positioning is accomplished through the use of cameras, eliminating the need for workers to provide guidance. The company projects a 30-percent decrease in replacement time with this liner, and notes that Metso makes mill liner installation equipment as well. In any case, plan ahead: it currently takes approximately one year for the delivery of a new mill liner (exact times depend on the mill liner size.)
The Finnish company Outotec demonstrated its newest product line, the high-intensity grinding mill, or HIGmill, for fine, ultrafine and regrind applications. At 22-m- (72-ft-) high, this is the largest mill the company has ever produced, and yet its footprint is no bigger than in older models and its flowsheet is uncomplicated. The new HIGmill enables a plant to control how material comes out of the mill, helping it to finetune the flotation process. Outotec brings the well-established technology of high-intensity grinding to a market processing more and more complex and fine-grained orebodies.
Like many new machines on the MINExpo floor, the HIGmill is advertised as low maintenance and optimized power usage. It has high energy intensity, but its vertical orientation enables it to achieve multiple grinding in a smaller footprint. It has low wear rates and easy maintenance. Its main range of application is ceramic grinding media of 1 mm-6 mm.
The mineral processing giant Weir was in the North Hall with an array of processing equipment lines gleaned from a decade of intelligent acquisitions. Its featured products emphasized brain over brawn, such as its new Linatex Wear Indicator System for hoses that handle highly abrasive materials. The Linatex Wear Indicator System is an embedded 24-hour monitoring system that can sense changes in resistance immediately, providing a more accurate and proactive maintenance response. Likewise, its custom-designed Vulco Mill Liner for hazardous applications can be tightened during service, improving safety and reducing work stoppages. Its Warman froth pump has a unique impeller inducer blade to handle heavy froth and higherviscosity slurries, enabling it to work smarter, not harder.
GIW, a leader in the heavy duty slurry pump industry, aims to break into the mineral processing supply chain with its new hydrocyclone. A sales representative on the MINExpo floor explained how they moved from pumps to processing. "Pumps are the links in the processing chain," he said. "We've been dealing with problems with other people's cyclones for years - we thought we knew how to fix these." For example, the GIW hydrocyclone is safe and quick to service, reducing machine downtime by up to six hours. It has a better wear life than the standard cyclone; its tongue-and-groove alignment and powdercoated steel construction are designed to last in high-wear environments.
The classic American pipe joining company, Victaulic Co., brought two new products to MINExpo, which, said a floor representative, is a lot for a pipe company. The AGS Vic-Ring System, introduced at the 2012 MINExpo, is a new connector for large-diameter high-pressure pipes, easing the installation and extending the service life of abrasive service piping systems up to 1.8 m (72 in.) in diameter. It improves the wear life of pipes that carry abrasive slurries by creating a smooth flow path and maintaining full pipe wall thickness. The Vic-Press is a flame-free press system that joins small-diameter stainless steel pipe in seconds. Company sales representatives demonstrated the press system in the booth and it was, indeed, fast and easy.
Longtime manufacturer of filtration systems, Donaldson Filtration Solutions, introduced new fuel filtration technology at the 2012 MIN Expo. Manufactured with Donaldson's Synteq XP media, these fuel filters are designed specifically to protect common fuel injection systems under dynamic conditions. "The fuel landscape has been changing rapidly for the last decade," said Rich Lewis, general manager of liquid filtration at Donaldson. One of the emerging challenges of the industry is that new high-pressure engines that run at 4,000 psi are very susceptible to contamination. To help address this challenge, Donaldson provides prestorage filters (these filter oil as it goes into a storage tank), poststorage filters (filter it as it is pumped out of the tank) and on-engine filters.
High tech has invaded every corner of the mining world, even the brute strength operations of crushers and grinders. Columbia Steel exemplifies the current trend to use technology at all points in the mining cycle in order to work smarter, not harder. This traditional manufacturer of steel crusher parts - bull liners, mantles, drag lines, weights - has developed a process to measure the rate of wear on a client's current mill liner. These measurements are then used to design the most efficient, endurance-based mill liner design for the type of ore crushed. They work with a company to provide a better solution, with more even wear, higher throughput and better efficiency.
Vermeer. a longtime stalwart of the construction industry, continues to move into mining with its growing line of terrain levelers. The T1655 terrain leveler, introduced at the 2012 MINExpo, is its biggest yet. Standing 6.7 m (22 ft) at its fullest extension and weighing 1 86 1 (200 st), it is built to be on the same playing field as the mining haul trucks. Despite its size, the T1655's specialty is precision. Its shallow wide cut enables consistentsized products to be extracted and its top-down cutting method results in a more uniform product. Its twoperson cab lets operators and trainers ride together. The cab has shocks to provide a smoother, quieter ride and the sales representatives said that one of the machine's great strengths is how clean and simple it is. It doesn't have a drive train: instead the all-hydrostatic engines are installed right on either side of the cutter drum.
MINExpo saw the launch of Micromine's new coal solution. Coal Measure, and a preview of its flagship geological exploration and mine design software, Micromine 2013. The new features and functionality contained within Micromine 2013 focus on resource estimation and modeling, pit optimization, annotation layers and scripting.
Coal Measure's two-step approach provides tools to collect, assemble, prepare and correlate all of the data associated with a project before modeling the deposit and designing the mine. This methodology speeds up the data correlation process and ensures errors are identified before modeling commences, saving time and money.
Micromine is a leading provider of software for geological exploration, three-dimensional mine modeling, resource estimation, pit optimization and resource scheduling.
GroundProbe, an Australian technology company, recently launched an innovative solution to improve the management of risk in openpit mining and civil and infrastructure projects. The Work Area Monitor (WAM) concept has been developed specifically to be operated by a mine production crew. It uses fastscanning radar, coupled with a high-resolution camera, to measure submillimeter movement trends and sound alarms to warn workers of ground movement or rock falls. The WAM can be deployed in minutes. The work crew operating the system simply selects the area it wishes to monitor on the touch screen, and the WAM will start looking for any movement. So long as the green lights are flashing. WAM has not detected rock movement. Every team member and vehicle is given a Personal Alert Device (PAL). If an alert is given, the device will vibrate, beep, flash and display a text message. The PAL can be mounted on a windscreen or worn on a hardhat, belt or sleeve.
For years, the mining industry has been trying to get communication devices to the face of mines, but due to regulations and explosion risks, technology devices were not allowed. Snively Inc. now offers a mobile personal digital assistant (PDA) that is approved by the U.S. Mine Safety and Health Administration (MSHA).
The Snively Mine Safety Tracker PDA, which was introduced at MINExpo, combines multiple functions in one device, including a Windows mobile computer, a phone (VOIP), a Wi-Fi device, a safety tool, a camera, a barcode scanner, a video recorder/viewer, a PDF viewer and a Global Positioning System. The device eliminates the need for manual data collection in mines and is built to MSHA specifications for intrinsic safety. It is also certified by ATEX in Europe.
3D-P, a MINExpo exhibitor, showcased its rugged, onboard, open-sourced computing platforms and wireless networks for mining operations. 3D-P's e57 Infrastructure Mobility Hornet is designed for light or heavy vehicle applications and features an 802.11a/b/g/n radio and a MotoMesh solo radio. The 802.11 radio can be configured as a 300Mbps high bandwidth backhaul client, while using the MotoMesh Solo radio in AP mode to provide backhaul to a pre-existing MotoMesh truck fleet. The 802.11 radio can also be configured as a Wi-Fi hotspot, making the e57 an access point for both the MotoMesh network, as well as an 802.11 network. The computing platform built in to the e57 Infrastructure Mobility Hornet supports all standard 3D-P onboard software utilities including full network protocol support.
The 3D-P open-systems design is not vendor specific, which allows a mine to connect any of its mobile or field systems, regardless of manufacturer. This includes every machine that has multiple onboard systems: dispatch systems, machine health systems, high precision GPS systems, slope monitoring systems, dewatering systems, video cameras and safety and security systems.
South African-based mining group Exxaro has purchased a high-speed, long-range laser scanner to support expansion projects and the building of two coal processing plants. The Riegl VZ 1000 will be used to survey stockpiles for volume verification, provide height analysis on earth works and blasting and to collect accurate measurements for terrain mapping and modeling. Thys Smith, chief surveyor at Exxaro's Grootegeluk coal mine, said, "The VZ 1000 gives us the necessary range and distance on the coal face, combined with the accuracy of data we require. The results can be integrated with our current software and solutions already in place in other areas of the business."
The Riegl VZ 1000 is a laser scanner with a wide field-of-view. It uses unique echo digitization and online waveform analysis to achieve accurate measurements, even under adverse weather conditions. Achieving accuracies of 5 mm at ranges of up to 1,400 m, the VZ 1000 can measure up to 122,000 points per second with a 100 360-degree field-of-view. The VZ100 was one of several Riegl products exhibited at MINExpo.
Michelin hosted a round table discussion of best practices and new ideas to improve productivity at the 2012 MINExpo. Nine industry professionals shared their visions for the future of mining and, especially, how new tire technology can help them improve their operations. The discussion centered around five major topics: the future of transport mining, fuel consumption and the environment, the features of an ideal tire, the tire as an information provider and how tirerelated service can improve productivity.
Roundtable participants included Rashpal Bhatti, vice president strategic supply, BHP Billiton; Mark Chappell, director of sourcing and supplier development, Barrick Gold: Robert Foord, president, Kal Tire: Rodolfo Frederico, general manager of mining and logistics global procurement. Vale Mining; Dan Funcannon, director of mining truck engineering, Komatsu America; Terry Gettys, director of research and development, Michelin Group; John McGagh, head of innovation. Rio Tinto Group; Alistair Swanson, general manger, Otraco International and Frederic Vincent, president, Michelin earthmover division.
The group reached a consensus on several issues:
* the need for increased the safety in the area of tire pressure and the dangerous job of changing tires.
* the need for an "intelligent" tire that provides in-cab, real-time data for tire pressure, temperature, road conditions.
* the need for onsite tire maintenance professionals.
* the need for more tires to meet current demand and a streamlined tire supply chain.
* and a vision for the future of driverless haulage.
Bridgestone Commercial Solutions (BCS). a division of Bridgestone AmericasTire Operations, rolled out a suite of products and services designed to increase a mine's productivity, and reduce costs with a constant regard to safety during MINExpo.
Bridgestone Mining Solutions (BMS) combines tire sales and repair with tire management and retreading to address every phase of a mine's tire-related needs.
"In talking to our mining customers, they told us what they need most is support in keeping their people and their work environment safe, help with increasing productivity and assistance in driving costs out of their operations," said Kurt Danielson, president, Bridgestone Commercial Solutions. "Although tires are our main product, we realize that service is key to increasing our customers' uptime. BMS is a response to what our customers wanted and needed: a total solution that speaks to each phase of tire life, helping them save money and increase productivity."
Bridgestone Mining Solutions include tire sales, consultation and support, repairs, rims and wheels, tire management, retarding and sustainability and the newest solution, B-Tag - a tire temperature and pressure monitoring system that helps automate a mine's tire maintenance practices.
Cummins Inc. announced at MINExpo that it plans to produce dual-fuel engines for minehaul trucks. The Cummins Dual-Fuel engine technology will substitute natural gas for diesel fuel in the combustion process, reducing the amount of diesel fuel required to operate mining equipment.
The first engine to receive this new technology will be the QSK60, with other QSK Series engines to follow, including those capable of meeting U.S. Environmental Protection Agency (EPA) Tier 4 emissions standards. A release date for the engines will be announced in the coming months.
Also at MINExpo, where Cummins displayed a line of engines from 37 kW to 2,983 kW (49 hp to 4,000 hp), the company revealed the QSK50 engine that is ready to meet EPA Tier 4 standards with up to 1,491 kW (2,000 hp) output for large mining trucks, excavators and loaders.
The 16-cylinder. 50-liter engine utilizes Cummins' selective catalytic reduction (SCR) aftertreatment system. The SCR system is designed as a drop-in replacement for the exhaust silencers. The system, combined with the cleancombustion enhancements to the engine, enable the QSK50 to lower operating costs by 5 percent.
During MINExpo, Hitachi introduced two new products. The most obvious was the new rigid frame hauler - the EH5000AC-3. It is the first hauler to feature the company's brand new Advanced Hitachi ac drive system, the only system available on the market that is designed and built by the same company as the truck.
Hitachi also announced that it has a new camera monitoring system. SkyAngle. that was developed in conjunction with Clarion Co. Ltd. The system takes synthesized images from several wide-angle cameras mounted on the truck and displays them in the cab. This results in a comprehensive "bird's-eye-view" of the surrounding machinery.
In addition to the proximity of machinery, the operator can switch to a "zoom display" or "wide display" mode, enabling more comprehensive monitoring of a wide area.
"The safety benefits of the SkyAngle system are tremendous. It allows operators to quickly grasp what is occurring around the machinery, such as position of other equipment, service vehicles or people," said Ryan Blades, division manager, Hitachi Mining. "This technology is yet another example of how Hitachi - by focusing only on shovels and haulers - is able to produce highly-efficient and productive machinery for mining operators across the world.
The new overview monitoring system is Hitachi's latest development in a slew of initiatives designed to enhance on-site safety.
The EH50O0AC-3 is Hitachi's largest rigid frame hauler and is one of the most technologically advanced mining trucks on the market today. It features a Cummins QSKTTA60CE diesel engine that generates 2.12 MW (2,850 hp) at 1,900 rpm and meets EPA Tier 2 emission requirements. The all-hydraulic actuated braking system provides precise braking control and quick system responses, and a new Hitachi system monitor provides display information and diagnostics of all onboard systems and controls.
At MINExpo GE Mining announced a new electric drive system for underground mining vehicles, while also letting the industry know that it intends to become a major player in the industry in coming years.
During a press conference, GE Mining unveiled its Invertex Electric Drive Systems that combine an ac drive system and GE's advanced Durathon battery energy storage system to propel underground mining vehicles with improved performance, increased reliability and lower life-cycle costs.
Invertex electric drive systems feature a compact variable frequency combo-drive that controls the traction and pump motors and is designed to improve wheel slip and speed-ongrade. The traction motor features frameless construction to reduce overall weight, a waterproof design to withstand wet conditions and an easy-access connection cavity. The advanced, scalable system controller offers multiple communications protocol channels, and a compact smart display shows real-time vehicle and system diagnostics. All components are designed to work as an integrated unit, making it possible to fine tune algorithms for optimal performance.
The Durathon battery energy storage system, a product of ecomagination, replaces diesel or leadacid battery systems with nontoxic sodiumnickel chemistry. The Durathon battery is 50 percent smaller and 25 percent lighter than traditional batteries, enabling more energy to be stored in a smaller space.
In August 2012, GE finalized its acquisition of Fairchild and created GE-Fairchild, which was added to the new division announced at MINExpo - GE Mining. The acquisition of Fairchild, along with an upcoming acquisition of Australia's Industrea, Ltd., are part of a development program announced in May 2012 to expand GE Mining to support approximately 35 percent of the underground mining value chain.
GE had about $2 billion in mining-related sales in 2011 and plans to boost that to $5 billion in a few years with the help of acquisitions, said Lorenzo Simonelli, the CEO of GE Transportation, which oversees the mining unit. It has already done deals to expand the mining business, announcing transactions in May for Industrea Ltd. and Fairchild International Inc.
Caterpillar introduced a slew of new products at MINExpo. The company's AD60 underground articulated truck has a rated payload capacity of 60 t (66 st). The machine provides a 9-percent capacity increase over the AD55B. The new truck incorporates advanced heat-shielding and cooling technology, significant refinement of its Cat C27 Acert engine, enhanced ride characteristics and now-standard monitoring systems, including the Cat VIMS Guardian and Truck Payload Management systems. Premium standard features include a choice of integrated body styles, electronic retarding, climatecontrolled cab and ground level servicing.
Caterpillar also introduced its new D series Unit Rig haul trucks, the MT4400 D and the larger MT5300D. The new D series model integrates a Cat 3516C HD engine and the Cat 240T ac electric drive system. The MT4400D, part of Cat's 218-t (240-st) payload class, is rated at a gross machine weight of 392,000 kg (865,000 lb). The MT5300D ac has a 290-t (320-st) capacity) and integrates a Cat C175-16 engine and a Cat 360T ac electric drive system.
The company's CM235 continuous miner is designed for low- to mid-seam operations. With two 205-kW (275-hp) cutterhead motors, it is the most powerful continuous miner in its class. It is designed for seam heights of 1.090 to 2,946 mm (43 to 116 in.). The machine's minimum clearance is 940 mm (27 in.) and its maximum cutting height is 3,250 mm (128 in.).
Caterpillar also introduced the largest hydraulic mining shovel ever built. The new Cat 6120B H FS shovel exceeds the size of the Cat 6090 FS to deliver highly productive three- or four-pass loading of ultra-class mining trucks. Innovative hybrid technologies cut fuel use per ton by an estimated 25 percent. This is done through the use of hydra-electric regenerative technologies and a unique energy storage system. The machine has an operating weight of 1.27 kt (1,400 st) and engine output of about 3.36 MW (4.500 hp), enabling it to handle dipper sizes of 46 to m3 (60 to 85 cu yd), depending on material density.
Joy Global's low-seam longwall system delivers capacities exceeding 270 kt/month (300,000 stpm). The system is capable of reaching as high as 7 m (23 ft), and as low as 1.3 m (4 ft). With components engineered to achieve higher production at lower cutting heights, the Joy Global low-seam longwall system is complete in the seamless integration of the shearer, armored face conveyor and roof supports.
The system provides greater operator safety through a remote operator control center that allows push-button control in full automation mode or manual override. The new low-seam Joy shearer reduces the risk associated with mining face geology variants and the synchronization of gate-end cut turnarounds. It will cut and load a full web, up to 10 times the width of that achieved by a plow.
Joy Global also exhibited some of its fuelefficient, mobile and productive P&H LeTourneau series wheel loaders. Each of the five Generation 2 models - beginning with the L-950 rated at 24.5 t (27 st) through to the L-2350 with a 72.6t (80-st) operating payload - incorporate the advanced Switched Reluctance technology with the LINCS II controls and monitoring system for reliable and fuel-efficient operation. The full line of P&H LeTourneau wheel loaders can meet productivity requirements ranging from 90 t/h (1,000 stphj with the L-950, up to more than 4.5 kt/h (5.000 stph) for the L-2350 model with fourto six-pass truck loading.
Philippi-Hagenbuch (PHIL) highlighted its HiVol hard rock/ore bodies. Designed with the hard rock and ore mining industry in mind, PHIL engineered its special hard rock/ore bodies to easily handle highly abrasive material, while minimizing carryback and maintenance requirements. The reduced-weight design also keeps operators comfortable, while allowing trucks to haul at maximum capacities.
PHIL customizes every Hi Vol truck body to the individual mine's specifications. To ensure the body will fit a company's application and specifications precisely, PHIL's engineers work with mining customers in identifying key factors that will impact the design of the truck body. Those factors may include density and cohesive qualities of the material, height and width restrictions, loading equipment and climate conditions. In addition, PHIL applies its proprietary Load Profiling process in examining the natural angle of repose, or how the material lays once it is dumped into the body, to maximize its payload capacity and reduce potential for material to fall out of the body.
PHIL also featured its line of rear eject bodies. Featuring ease of use, safety, stability, minimal maintenance and increased productivity as hallmarks of its design, the company's line of rear eject bodies can handle challenging hauling applications from surface mine operations and underground hauling applications where overhead barriers inhibit traditional dump bodies. These rear eject bodies can be adapted to any make and model of articulated off-highway truck as well as rigid frame trucks up to 90 1 (100 st).
Sandvik launched its next generation of underground trucks at MINExpo. The TH551 and TH663 are the latest innovative additions to Sandvik's underground ramp hoisting truck family. The TH551 and TH663 are engineered to Sandvik's LH517 and LH621 loaders. This productivity partners concept allows for a fast three-bucket loading system that increases the load and haul cycle efficiency, resulting in high levels of overall cycle productivity.
With more than 63 safety features to protect the operator, maintenance staff and the truck itself, the TH551 and TH663 are probably the safest hoisting trucks ever made. Through intelligent design, the TH500 600 series' trucks also offer maximum operator comfort. They have been designed and built with high reliability and ease of maintenance in mind. Particular attention has been given to the replacement time of large components, such as engine transmission, resulting in significant increases in uptime hours and the total tons per year hoisted.
The company's bolter miner was first put into operation in Australia in 1991 . Since then, a variety of models have been introduced to meet specific demands of mines all over the world. Sandvik's bolter miners have a unique sump mechanism that enables them to cut and bolt at the same time. That is the key to high-speed gateroad development.
The MB610 bolter miner has a low cutting speed of 31 rpm, compared with 60 rpm in other models. The lower cutting speed delivers high torque and higher cutting forces and generates less dust during the cutting process. Lower cutting speed also ensures low noise levels.
The MB610 features a unique movement of cutter drum and loading pan that allows independent movement of the cutter drum and loading table. This enables good maneuverability to cut a clean 90-degree crosscut within a short radius.
Atlas Copeo introduced its new Pit Viper 311 rotary blasthole drill. The Pit Viper 311 is similar to the Pit Viper 351 with its single-pass drilling. However, the Pit Viper 31 1 has the capacity to drill holes deeper to a maximum depth of 38 m ( 125 ft). Drilling up to 20-m (65-ft) clean holes with a live tower can reduce nondrilling time and, combined with taller benches, can increase production capability. The drill offers a narrow range of hole sizes 230 to 310 mm (9 to 12.25 in.), which fills the gap between the hole ranges of the Pit Viper 351 and the Pit Viper 270.
The PV310 has a fully adjustable chair with joystick and cab controls. It has been elevated above the deck to give the operator a better view. The Pit Viper 311 offers drive train options with Tier 4 and Tier 2 diesel engine alternatives. The tower has an interchangeable unit, structurally similar to the Pit Viper 351, but is deeper so that it can accommodate larger sheaves for either single-pass or multi-pass applications. Bits can be changed above the Pit Viper 311 rig's deck, even while single-pass drilling 20-m- (65-ft)-deep holes so operators will have their eyes on making and breaking the connection each and every time.
A multi-pass version of the Pit Viper 31 1 , known as the Pit Viper 316, is now under development. It will drill to a depth of 90 m (295 ft) using a fiverod carousel with 15-m (50-ft) drill pipe. The Pit Viper 316 is scheduled to be launched during 2013 as a replacement to the DM-M3 model. It will specifically match the flexibility required for castblasting operations in coal mining.
Atlas Copeo also previewed the world's largest articulated underground mining truck, the Minetruck MT85. This truck is designed to fit the same drift dimensions of 50 to 60 t (55 to 66 st) class trucks with one essential difference: It will haul 85 t (93 st), which increases productivity through the use of fewer trucks and more tons per mile hour.
The Minetruck MT85 has a high capacity with a compact footprint. It is 3.4 m (11.1 ft) wide and 3.5 m (11.5 ft) high, enabling it to fit into 6- 6-m (19.7-ft 19.7-ft) drifts. And, despite its length (14 m or 46 ft), it has a turning radius of 40 degrees.
MINExpo attendees were able to visit three indoor halls and one outdoor exhibit area.
Liebherr displayed two mining trucks (T284 and T264), as well as a pair of excavators, including this R 94000 at MINExpo2012.
Attendees walk in the shadows of some of the large mining equipment on display at MINExpo.
Cummins displayed its extended line of engines for mining equipment.
Attendees walk in the shadows of some of the large mining equipment on display at MINExpo.
In addition to displaying its drill, like the one shown here, Sandvik exhibited a number of pieces of underground mining machinery.
by Emily Wortman-Wunder, Technical Editor, Georgene Renner and William Gleason, Senior Editors and Steve Krai, Editor
(c) 2012 Society for Mining, Metallurgy, and Exploration, Inc.
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