Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr
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OPERATING STRATEGIES APRIL 2016 • E&MJ; 75 www.e-mj.com the blast was 19 m, and the explosive was initiated from both top and bottom. "The improved control of the blast helps keep vibration levels down," said BME Technical Director Tony Rorke. "This in turn improves safety in the open- cast mining environment, as high vibra- tion levels can undermine the integrity of the pit wall." To design the blast, the Daunia team used BME's BlastMap III blast design software, which was developed as an integral part of the AXXIS system. The program allows complex timing designs and analysis of the results for each blast, and has just been released in an up- dated, second-generation version labeled BlastMap GII. Mines Can Benefi t From High-effi ciency Motor Upgrades By Chris Medinger Mining and metals production are ener- gy-intensive processes, with a signifi cant proportion of energy consumption coming from purchased electricity. According to the Southwest Energy Effi ciency Alli- ance—one of a number of regional energy effi ciency organizations across the United States—a metal mining company's energy expenditures can represent between 20% and 40% of its total production costs. However, today's highly effi cient motors, drives and mechanical power transmis- sion products can signifi cantly reduce the amount of energy consumed. To encourage mining companies to retrofi t standard motors to high-effi ciency motors, a number of incentives and re- bates are available from sources in the U.S. and elsewhere. For example, as far back as 2010, the U.S. Senate introduced legislation to create a rebate program to encourage the sale of high-effi ciency in- dustrial motors. The program was set up to provide a $25 per-horse power rebate for customers who purchased a high-effi - ciency motor for industrial and commer- cial use, including mining. In Canada, Ontario's mining industry spends more than $500 million annual- ly on energy, which represents on aver- age between 15% and 30% of operating costs, depending on the type of mining operation. To shorten payback periods, reduce capital costs, and cut operating expenses, Canada's saveONenergy offers incentives for upgrading to premium effi - ciency motors. In the European Union, electric mo- tor-driven systems account for approxi- mately 70% of total industrial electricity consumption and are responsible for ap- proximately 60% in China. While replac- ing individual motors can save 3%–5%, optimizing entire motor systems could cut consumption by 20%–40%. Legisla- tive efforts have been under way in sev- eral countries for more than a decade to encourage the transition to more effi cient electric motor-driven systems. The U.S. Department of Energy has explored and compared major industrial market verticals and energy use by ma- jor process systems. Its study noted that the mining industry ranked as the third- highest energy user of motor-driven sys- tems among 10 major industry verticals. Mining's high position as an industri- al energy consumer means that, under the right circumstances, mine operators could signifi cantly benefi t from invest- ments aimed at upgrading existing mo- tors, such as: • Retrofi tting or replacing under- ground support systems; e.g., venti- lation fans and air systems. • Upgrading motors or replacing con- veyor systems. • Effi ciency improvements to crush- ing, separating or materials trans- portation processes. • Retrofi tting pumping systems in mine dewatering, slurry transporta- tion and tailings disposal. • Improvements in extraction and re- fi ning processes. • Improvements in control systems or sensors. • Installing variable speed drives for pumps, compressors and operating fans at partial load capacity. Selecting the proper motor for an ap- plication—and providing adequate main- tenance for it—are key elements in mo- tor effi ciency and performance. Consider the staggering costs of downtime: Accord- ing to Caterpillar, it's estimated that the total cost of unscheduled downtime can be as much as 15 times that of a sched- uled event. Maintenance, because of its impact on return on capital, is a key driv- er of performance. By reducing maintenance costs, com- panies can improve their performance. Preventative maintenance and regular analysis of motor load test performance are essential to achieve reliable perfor- mance. Selecting the right high-effi cien- cy, heavy-duty motor for mining equip- ment is a critical step for OEMs and end-users. When a motor is put into an application that it is not designed for, it will cause many kinds of repetitive repair issues that even the best preventative maintenance practices will not correct. When motor failures do occur, most can be attributed to bearing problems, and bearing failures usually stem from issues involving lubrication. Antifriction bearings should be re-lubricated on a regular basis. The lubrication schedule depends greatly on the motor's operat- ing environment and service conditions. While failures may occur due to lack of lubrication, bearings may also fail due to grease contaminated by water or other materials. The second most common cause of motor failures is stator-winding failure. To ensure long motor life, it is important the motor operate within the temperature class of its insulation system and be kept clean and free of particle build up on the frame surface, air inlet and fans. Mining companies are looking at cut- ting costs by, among other things, using more effi cient equipment to ease en- ergy demand and reduce downtime. In- creasing investment in high-effi ciency, heavy-duty motors would separate profi t- able, growth-oriented companies from the pack and equip them with a sustainable competitive advantage. The payback times for motor invest- ments can be within a couple of years and offers a positive impact on both the environment and the operation. The min- ing community is being challenged to fi nd electrical equipment and systems solutions that make mining operations reliable, effi cient, and continuous; safer and protected; and sustainable high-effi - ciency, heavy-duty motors are one way to achieve these goals. Chris Medinger is product marketing specialist with Leeson Electric and may be reached at (262) 387-5410 or chris. medinger@leeson.com. Leeson is a Re- gal brand located in Grafton, Wisconsin, USA. Regal Beloit Corp. is a leading man- ufacturer of electric motors, mechanical and electrical motion controls, and power generation products.