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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Drilling and blasting operations, perhaps more than any other mining activity, illus- trate how even the best-laid engineering plans and designs can go amiss in real- world situations. In an ideal setting, all blastholes in a given pattern are drilled correctly, loaded properly, initiated in exact accordance with timing specs and produce the full intended effect. That's not always the outcome, and unintended results can have significant effects on downstream operations ranging from secondary breakage costs and load- ing/haulage problems, to processing ineffi- ciency and higher energy costs per ton. With drilling costs alone reported to account for between one-third and one-half of total D&B; costs at many mines, signifi- cant economic benefits may be gained by finding solutions that can cut—or at least control—drilling-related expenses and re- source demands that arise from operator mistakes, unplanned maintenance and higher-than-expected consumables deple- tion, to name just a few concerns. Drilling equipment manufacturers offer a variety of services and options to achieve cost-reduction and productivity objectives, ranging from procedure-based solutions such as operator training and drilling effi- ciency studies, to hardware options or drill- fleet upgrades. New equipment, including many of the recently introduced rigs and tools described below, is generally avail- able with standard or optional features that can help operators avoid drilling errors caused by inexperience, lack of situational awareness or even complex and change- able local geology; and design improve- ments often make it possible to drill at higher penetration rates—with lower main- tenance intervals—and with equal or pos- sibly even less consumables usage. Rotaries Evolve to Meet Market Demands Atlas Copco's latest rotary rig, the PV-311, was introduced to the commercial market just as this issue of E&MJ; was going to press. The company said it has applied a high proportion of proven technology from previous rigs in the Pit Viper series to this model, furthering progress towards greater energy efficiency, safety and productivity. For example, the popular Pit Viper hydraulic top-head drive rotary head was retained, as well as the automatically ten- sioned hydraulic cable feed system and hydraulic breakout tools. The elevated cabin of the PV-311 is larger than the PV- 351's and has additional improvements over the PV-235's cabin. The live tower is capable of single-pass drilling 65-ft (19.8- m) clean holes, with bit changing above deck. The rig is designed to handle 7-5/8- in. to 10-3/4-in. drill pipe for sinking blast- holes up to 12-1/4 in. diameter. In addition, said Atlas Copco, the new rig offers enhanced serviceability, ground- level accessibility for components and 38 E&MJ; • MARCH 2014 www.e-mj.com S U R FA C E D R I L L I N G Rigs, Rods and Bits Review Increasingly intelligent machines and tougher drill string tools are capable of taking a mine's drilling program to higher levels of performance and economy By Russell A. Carter, Managing Editor Atlas Copco's newest rotary blasthole drill rig is the Pit Viper PV-311. EMJ_pg38-41_EMJ_pg38-41 3/3/14 12:15 PM Page 38