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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In the year that has passed since the last review of equipment designed specifically for narrow-vein mining environments, it has become clear that there is still strong demand from the industry worldwide for these machines. True, lower commodity prices—particu- larly for gold—have hit producers where it hurts, and this has particularly been the case for companies that work high- er-cost narrow-vein operations. Yet conversely, this is precisely the rationale for equipment manufacturers to develop ranges of machines that answer the needs of narrow-vein deposits, by providing mechanization that helps to improve productivity and reduce the physicality of drilling and mucking in tight spaces. As the vice- president for domestic sales at J.H. Fletcher & Co., Ben Hardman, told E&MJ; , the company is concentrating on helping customers with narrow-vein operations to cut mining dilution rates. "We believe that focusing on roof bolters is the best way to help," he said. "Our aim is to help operators that are using jackleg drills for installing roof support to mechanize—to get rid of as much of the 'grunt' work as possi- ble," Hardman added. "It's a two- pronged approach: making working con- ditions safer for the mining workforce, and getting better productivity by using specialist machines." And the rationale does not stop at bolting, of course. Development, stop- ing, mucking and hauling have tradition- ally been labor-intensive operations in narrow-vein mining, with each of these operations fair game for mechanization that can make the job lighter and the individual miner more productive. On the other side of the equation is the investment cost involved in equip- ping a narrow-vein mine with new machines, and the need for high-quality maintenance to ensure that they work efficiently. Nonetheless, more and more producers are seeing the benefits of this investment, particularly in places where skilled mining labor is in short supply. It is often the case that a good mechanic is easier to find than an experienced driller, with the sophistication designed into today's drill rigs and load haul dumps (LHDs) making the miner's task easier and less physically demanding. Mechanized Roofbolting Brings Benefits With a long-standing focus on special- ist equipment for roof support, J.H. Fletcher & Co. offers a number of machines that find applications in nar- row-vein operations. According to Hardman, Fletcher has recently deliv- ered three new machines to narrow- vein operations. The first of two N3112-AD/E bolters ordered by Still- water Mining Co. started work there at the beginning of the year, while a com- pany in Mexico has taken delivery of a 3116AD/E machine. The third recent supply was an N3117-AD bolter, de- signed for use in headings from 3-m (10 ft) wide and now in use at Chevron Minerals' Questa molybdenum mine in northern New Mexico. Using an "operator-up" design, whereby the operator can control bolt drilling and installation from the bas- ket, these machines are designed to get rid of the need for stope backfilling before roof support can be installed, explained Fletcher's business develop- ment manager, Bill Goad. "Working with our customers, we have developed these machines to address specific requirements," he said, "and we always try to use existing components wherev- er possible, to cut development time and ensure parts commonality between different machines. "Now that they are working, we are getting a lot of interest from narrow- vein operations around the world," he said. The N3112 rigs for Stillwater are designed to install side support in nar- row headings and stopes in steeply dip- ping formations. With center articula- tion, the machine can negotiate turns with as little as 2.5 m (8 ft. 3 in.) inside radius, while the drill unit can reach to a top height of 4.4 m (14 ft. 6 in.). With a length of 10.5 m and just 1.23 m wide (34 ft. 8 in. x 48½ in.), the rig uses a Cummins diesel engine for tram- ming and electric power for bolting. 28 E&MJ; • MARCH 2014 www.e-mj.com N A R R O W V E I N M I N I N G Mining Machines for Small Spaces E&MJ; looks at recent developments in specialist machines for narrow-vein mining By Simon Walker, European Editor This view of J. H. Fletcher's N3112AD/E bolter highlights the company's "operator-up" design, allowing the operator to control both bolt drilling and installation from the basket. EMJ_pg28-37_EMJ_pg28-37 2/28/14 3:10 PM Page 28