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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72 E&MJ; • DECEMBER 2015 www.e-mj.com P U M P I N G S Y S T E M S Choosing the right pump for a specific application can have a major, lasting impact on overall operational efficien- cies. In the first portion of this two-part article, Nate Maguire, Americas busi- ness unit director–industry and agricul- ture for Xylem's applied water systems business unit, highlights an all-impor- tant point: Pumps used in mining appli- cations are subject to the harshest and most demanding conditions on earth. From dewatering to mineral extraction, pumps are required to perform effi- ciently in difficult conditions and for long hours. It is important to select the most appropriate pumps to efficiently handle these adverse environments and deliver the best application results. As an example, Maguire told E&MJ; that a large gold mine in Colorado, pro- ducing more than 200,000 ounces per year (oz/y), uses vertical turbines in its operations, which employs heap leach- ing for precious metal recovery. Thirteen vertical turbines are used at the mine, with three new 800-hp tur- bines recently put in place. Each tur- bine is 150 ft long and pumps 3,000 gallons per minute with 600 ft of head. To leach gold from the ore, mined rock is crushed and piled onto a lined leach pad. A diluted solution of sodium cyanide is applied using agricultural- type drip irrigation tubes. The heap is an engineered collection system that in a way resembles a large mixing bowl, the center of which acts as a sump, designed to collect the water-cyanide mixture that is sprayed on the ore. Over a period of months, the solution per- colates through the heap liberating the gold as it passes through the ore. The pregnant solution is then collected from the sump. Large turbine pumps are used to move the pregnant solution up out of the sump to a processing facility 1,000 ft. away. After the gold is extracted, the water-cyanide solution is pumped back to the heap-leaching site for reuse, or Pumping Out More Profit Two 'success' stories illustrate the importance of choosing the correct pump type, materials, and accessories to cost-effectively meet common mine-site fluid and slurry transfer demands At a Colorado gold mine that uses heap leaching to produce more than 200,000 oz of gold annually, 13 vertical turbines are currently in use; each turbine is 150 ft long and pumps 3,000 gal/min with 600 ft of head.