The ASIA Miner - Reporting Important Issues to Mining Companies in the Asia Pacific Region
Issue link: http://asiaminer.epubxp.com/i/786114
VDMA 55 2017 • VDMA MINING SUPPLEMENT each with a power rating of 3,800 kW, and the associated Sinam- ics SL150 cycloconverters, E-House cooling system and convertor transformers. In 2015, Siemens commissioned direct conveyor drive systems for two additional copper mines. One was for one of the largest copper mines in the world, which is located in Chile (5 x 5,000 kW). For the overland conveyor supplied by thyssenkrupp with a length of more than 10 km, Siemens supplied five direct-drive systems (for a total of four conveyors) with the largest conveyor motors pres- ently in operation. The overland conveyors at Las Bambas copper mine in Peru were designed and supplied by thyssenkrupp and have been in operation since the fall of 2015. Each of the two overland con- veyors is approximately 2.5 km long with a lift of almost 300 m and transports ore from the mine to the processing plant. The belts are 1,830 mm wide, travel at 6.5 m per second, and are designed to transport approximately 9,400 mt/h. The stockpile at the end of the conveyor system is more than 50 m high and can sup- ply the processing plant with up to three days' worth of copper ore for processing. The drive system for each of the two overland con- veyors comprises two low-speed synchronous motors — each with a total power of 4,400 kW — and the associated Sinamics SL150 cycloconverters. The overland conveyors at Las Bambas were commissioned very quickly and the conveyor system is now in operation. "The proj- ect has been very successful and we are running the conveyors at nominal capacity with only a very few open issues. The gearless drives are beneficial from a service point of view, given that there are no motor bearings or gearboxes, which simplifies ongoing main- tenance requirements," said Timothy Mess, project director for thys- senkrupp. Peter Mizera, MMG's general manager for Las Bambas project delivery, shared a positive view of the project outcome. "Las Bambas has been a great success, and Siemens was a large contributor to this out- come," Mizera said. "Siemens provided solid support during construction, precommissioning, and commissioning, and as a result, we were able to complete the overland conveyor commissioning very quickly — in just under two months. This was a fantastic achievement." Following Las Bambas, Siemens recently supplied the world's highest-powered direct conveyor drive system to the Cuajone mine in Peru. The modernization project will entail the installation of a new gyratory crushing and conveyor system from thyssenkrupp by 2016 (See Material Handling, p. 25). Siemens proposed an Integrated Drive System with direct conveyor drives to power this conveyor sys- tem, which has a total power output of 12,000 kW. The conveyor belt system comprises three individual sections that are equipped with a total of five Integrated Drive Systems. For the largest of the belt sections, Siemens is supplying two drive systems with an output of 6,000 kW each, comprising a low-speed synchro- nous motor and a Sinamics SL150 cycloconverter. The two smaller feed and discharge belts will be driven by two 500-kW low-voltage motors powered from Sinamics S150 converters with regenerative feedback capability and one 1,200-kW medium-voltage motor. The converters and motors as well as the gearboxes and couplings for these drives are all supplied by Siemens. The automation components and the drive and power distribution technology are provided in modular electrical rooms. Over the years, Siemens has improved and optimized the cooling system, the mod- ular design of these electrical rooms, the power distribution, and the automation and drive control so that they perfectly address the mining industry's specific requirements. At Cuajone, Siemens will continue the company's impressive track record of successful projects in South America — and reinforce its position as one of the leading suppliers of electrical and automa- tion systems for the global mining industry. Fuel Filtration System To ensure reliable performance for Series 4000 mining engines operating in harsh conditions where fuel standards are difficult to uphold, MTU engineers designed a new upgrade to the fuel filtration system. The goal was to improve the system's ability to remove par- ticle contaminants in the fuel before they reach the injection system. The first aspect of the upgrade involves replacing the filter el- ements within the primary and secondary filtration unit with new MTU high-efficiency filtration elements. This ensures that filtered fuel meets the standards required by the Series 4000's common rail injec- tion system. To achieve such high efficiency, the filter elements are embedded with extremely fine glass fibers, which enable a very high separation with maximum dirt holding capacity. The MTU High Per- formance Fuel Filtration kit includes two primary and two secondary filter elements. The new filters are designed to have similar change-out intervals as the original filters. In extreme conditions, a significant increase in filtration is often accompanied by a reduction in filter lifetime with- in the primary and/or prefiltration system. To compensate for these reductions, MTU developed additional upgrades for both pre- and primary filtration units. To test the MTU Fuel Filtration Upgrade Kit, prototypes were in- stalled in 20-V 4000 MTU engines in 360-ton Liebherr T-282 mine haul trucks, at three mine sites: North Antelope Rochelle mine (Wy- oming, USA), Kaltim Prima Coal (Indonesia) and Mount Arthur Coal (Australia). As a benchmark, a standard fuel filter was installed in a similar truck at each site. Both trucks at each site endured a full 7,000 hours of operation under the same conditions. After the testing period, all the injectors were inspected and the results showed the new filtration offered significant improvements. Injectors showed less wear at 7,000 hours than at 3,000 hours with the original filtration system. Most cases showed a 50% to 60% im- provement in longevity. In some cases, injector life was doubled. Removing the necessity of an injector change just once over the lifetime of an engine offers significant savings. In harsh con- ditions, several changes can be avoided. With the high-efficiency fuel filtration upgrade kit, reaching the expected life of the injector components is possible, even when fuel quality standards are dif- ficult or impossible to meet. In addition, fuel efficiency is improved and the risks of engine damage by worn injectors and other com- ponents are minimized. One of the first mine operations to choose the new upgrade kit was the Radomiro Tomic copper mine in Chile, one of the most challenging sites in the world to meet stringent fuel standards. Lo- cated 9,800 ft above sea level, dust is ever-present and fuel must go through multiple transfers on its long trek to the site. Previously, injectors achieved nearly 4,000 hours of life. With the installation of the new upgrade, they are now achieving more than 8,000 hours. Unexpected equipment downtime has been dramatically reduced as well. In addition to solving the problems associated with fuel con- tamination, the upgrade kit enabled the mine to keep following the same exchange intervals as the previous series production filters. Many haul truck engines at Radomiro Tomic work more than 20 hours a day. Every time equipment is down, it costs the mine operator mon- ey. Reducing maintenance time pays off exponentially over time, and across many vehicles in the fleet.