Underground mining continues to dominate the coal industry as mining companies strive for ever-scarcer resources, hidden deep underground. Innovative developments and new products are attempting to increase productivity and efficiency to achieve minimal cost/t in coal extraction.
Caterpillar is expanding its CM200 series with the CM235 continuous miner, which has been developed for low- to mid-seam operations of 10 – 30 m high. It offers loading rates of 14 – 29 t/min and its 2 x 205 kW motors make it the most powerful continuous miners in its class. A variable frequency drive traction system improves the machine’s manoeuvrability.
Meanwhile, the EL3000 is Cat’s latest longwall shearer, designed for mining seams from 2.7 – 5.4 m in height. The shearer comes with 2 x 860 kW cutting power and 2 x 150 kW haulage motors, delivering production capacity of over 5000 tph. The EL3000 has a state-of-the-art automation system for the control, monitoring and protection of the equipment.
Caterpillar has also developed a personnel proximity detection system for underground miner safety. Cat Detect Personnel (CDP) is part of the Cat MineStar system, and uses radio frequency identification tags on individuals and machines. The control system receives location information from all tagged entities and takes appropriate action, such as inhibiting machine movement and providing warning signals as necessary. Each tag incorporates a battery-powered transponder and an identifier that can be configured to suit the needs of the mine: for example, to identify personnel and/or the wearer’s job title and skills. This information could therefore be used in scheduling and personnel assignment. The tags and readers are small, consume little power and there is no delay in transmission.
CDP for longwall systems is being tested in underground operations in the US and Europe, with commercial availability expected in Q4 2012. CDP for continuous miners is in development.
Joy used MINExpo 2012 to launch its new low-seam longwall system, which integrates the shearer, armoured face conveyor and roof supports. The system is specifically designed for a low-seam mining environment, as low as 1.3 m. The system’s remote operator control centre improves safety by removing the operator from the mining environment, allowing automated control. The Joy system can reduce waste by up to 40% and achieve operational cost savings.
Joy also announced the development of Phase 2 of the Joy SMARTZONE proximity detection system. Phase 1 has been operating since 2009 in 53 mines in the US. It emits an electromagnetic signature and radio frequency identification signal that allows independent identification from a device worn by the operator. Phase 2 will expand on the capabilities of Phase 1, and will offer a platform usable on all section equipment, offering a seamless interaction between multiple systems. It is currently in development and expected to be released in mid-2013.
Kennametal has introduced the PrimePoint™ Productivity Customers Demand complete value programme to bring its new picks to its customers.
Kennametal’s new high-efficiency PrimePoint picks feature a tip with a new thinner cross-section that reduces respirable dust and lowers power consumption while increasing material size. A proprietary body reduces breakage and extends service life.
Under medium cutting conditions, using PrimePoint picks has yielded 1270 – 7076 t ROM per tool, compared with 318 – 1180 t with conventional carbide tools. Under heavy cutting conditions, PrimePoint resulted in 300 – 1500 t ROM coal per tool, compared with 100 – 300 t with conventional carbide tools. And under severe cutting conditions, PrimePoint has yielded 9 – 272 t RoM per tool, compared with 9 – 45 with conventional carbide tools. Overall cutting efficiency in medium and heavy longwall mining operations can increase up to five times current levels.
Minova used MINExpo to launch a range of new products for underground mining operations. Carbothix is a two-component silicate resin for binding rock bolts, supporting injection bolts and rod anchors. Its fast setting time prevents resin from leaking from boreholes and makes it an efficient solution for anchoring in tough geological conditions. After four hours, bolts secured with Carbothix can sustain loads of up to 360 kN. In addition to injection and filler grouting applications, Carbothix can be used for reliable sealing against flowing water. The company’s patented new tensionable cable bolt (TCB) system can be tensioned during ongoing bolting operations, which improves support for sidewalls and roof structures.
Minova has also developed a spray-on concrete that sets and can sustain loads in under 15 min. Tekcrete Fast, created with the University of Kentucky, is a combination of polyfibre and cement that has been developed as a quick-acting solution for stabilising buildings, bridges or tunnels at risk of collapse after a natural disaster or similar incident. Secured in this manner, emergency services would have safe access. Tekcrete Fast M guarantees even stronger bonds and less dust during processing, making it ideal for mining safety. It has been approved for use in mining and tunnel construction to reinforce tunnel roofs. Within 15 min of application, the quick-cure shotcrete is fully cured and can sustain pressures of up to 2000 psi.
Phillips Machine Service
Phillips Machine Service introduced a new, technologically advanced shuttle car at MINExpo 2012. The new car has a redesigned operator control station for improved comfort, safety and capacity. This new command centre for the car also uses video cameras to remove blind spots and allows functions to be monitored in real-time.
The new VersaRide four wheel suspension system greatly improves operator comfort without compromising on load carrying capacity, and additional proximity detection devices increase the safety of all workers in the vicinity.
The first Sandvik bolter miner was put into operation in Australia in 1991. Since then, updates and adjustments have been made to meet the specific demands of mines around the world. The new MB610, launched at MINExpo, has a lower cutting speed to deliver high torque and higher cutting forces, and generates less dust. The lower cutting speed also reduces the noise levels.
The MB610 was specifically developed for the US coal mining market and has been approved by the Mine Safety and Health Administration (MSHA). Further features include: a low minimum tramming height of 2 m; auto-stabilisers that ensure low ground pressure of 25 psi; roof bolters that can tilt up to 37° for flexibility; and a unique movement of cutter drum and loading pan, which allows independent movement of the cutter drum and loading table for improved manoeuvrability.
Adapted from press releases by Lauren Bryant.
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