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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PUMPS & PIPING also on the anticipated number of annual operating hours and the price of electricity. Since most submersible borehole pumps can be expected to run many thousand hours a year, a gain in efficiency amounting to just a few percentage points can translate into major savings, justifying the purchase of a new pump, the company states. Tailings Pumps for Mali's Gold Mines A KSB 8-in. UPA 200 submersible borehole pump. The selection of the correct dewatering pump can give big energy savings, the company says. pump's operating time to 5,000 hours per year and throttle the flow rate to approximately 100 m3/h. While the unthrottled pump achieved better than 50% efficiency, throttling reduced this to below 40%. Analysis showed that this pump needed an energy input of around 151,000 kWh/y under these conditions. However, KSB says, by replacing this pump with a new unit, correctly designed for the duty and with a lower-resistance power cable, the energy demand fell to just 93,600 kWh/y, representing a saving of 57,400 kWh/y to achieve the same capacity. To summarize, the viability of investing in a new, more efficient pump depends not only on the size of the pump set itself, but 70 E&MJ; • APRIL 2013 Putzmeister Solid Pumps is part of the larger Putzmeister group, which specializes in areas such as concrete pumps for construction, and shotcreting systems for underground mining and tunneling. A key area of expertise is in the design of oilhydraulic high-pressure piston pumps that are used for transporting and storing sludges and high-density solids such as mine tailings and concentrates. The company recently completed an order to supply pumps to Randgold Resources' Loulo and Gounkoto gold mines. Located in the west of Mali, the mines are situated within the KedougouKenieba inlier of Birmian rocks that host a number of major gold deposits, including Sadiola, Gara, Yalea and Gounkoto. In mid-2012, Putzmeister Solid Pumps received an order from Randgold for the design and fabrication of four hydraulically driven piston pumps with a flow rate of 150 m3/h and a delivery pressure of 90 bar. The pumps were designed for backfill operations using material from the treatment plants. Following a design, fabrication and test phase totaling 37 weeks, the four pumps were shipped to the mine site in December. Putzmeister reports that the type KOS 25.100 HPS pumps, with HMC-S valves and an 800-kW hydraulic power pack, will be in operation at the end of this year. Each of the pumps has two, 2,500-mmlong, 360-mm-diameter (98-in. long, 14-in. diameter) delivery cylinders, while the hydraulic power pack is equipped with sound-protection panels and a special cooling system. The KOS pump type is a valveless, twocylinder piston pump that is suitable for conveying all kinds of thick media with a high solids content. The KOS 25.100 HPS consists of a hopper with two agitators, two hardened delivery cylinders with one delivery piston each, and a so-called S-transfer tube, connecting the delivery cylinder to the output flange. The changeover of the S-tube during operation is carried out by two plunger cylinders. Two hydraulic cylinders are used as the driving unit for the delivery cylinders. An intermediate water box (between the hydraulic and material cylinders) allows the cylinders to be flushed and cooled, as well as giving access for quick replacement of a piston during maintenance. Quick-fit Pipes with a Long History Victaulic manufactures a range of pipejoining solutions for the mining market that, it says, offer faster, safer and more efficient assembly of piping systems. From a mine owner's perspective, using Victaulic pipe can cut installed costs by up to 50%, it claims, while its products are safer and faster to install, reducing the opportunity for injuries. This type of pipe system can also cut maintenance times significantly, keeping plants running more efficiently. For piping installers, they have the advantage of faster installation without the need for special tools, while the availability of reusable parts speeds up maintenance. The company notes that in the U.S. and Canada, grooved mechanical piping is the generally accepted method for joining pipe in the mining industry. The mechanical joint consists of four elements: groovedend pipe, a gasket, coupling housing, and nuts and bolts. The primary and perhaps best-known benefit of these systems is that they are three to five times faster to install than other methods of pipe joining, while the couplings can be orientated in any direction during installation, making it easier to install pipe ranges in tight spaces. Putzmeister Solid Pumps recently supplied four units to Randgold Resources' operations in Mali. www.e-mj.com