IM 2017 April | Page 55

MINING PUMPS pump. When the valve closes, the seal against the lip-ring on the low suction bottom prevents the water from flushing out and emptying the hose. The Milli pump excels in applications where reliability and easy handling are essential. It is built to handle contaminated water, pH 5-8, and water containing relatively abrasive solids up to a size of 5 mm. MHWirth pumps for hydraulic ore hoisting Wirth™ slurry pumps by MHWirth are used for various heavy duty applications in the mining industry, such as mine dewatering, autoclave and digester feeding, and transport of tailings and concentrates. A highlight in MHWirth’s pump applications is the world’s first hydraulic ore hoisting operation at both the McArthur River and Cigar Lake mines in Saskatchewan, Canada. The Canadian company Cameco is using four Wirth™ TPM piston diaphragm pumps for the hydraulic ore hoisting application at its uranium operations. Uranium ore is crushed underground, mixed with water and pumped to the surface as slurry where it is subjected to further processing. Elsewhere, in South Australia, DPM piston diaphragm pumps by MHWirth have proven their efficiency as an energy and water-saving solution for large-scale tailings transport. With a particularly high capacity of more than 700 m³/hr, MHWirth’s DPM is one of the largest pumps in the field. Pulsation free backfill pumping The mining industry has recognised the advantages of high density backfill or ‘paste’, which is typically pumped with a hydraulically driven piston pump. However, due to the discontinuous flow of this type of pump, pressure pulsations can occur in the discharge line. Erik Vlot, Product Manager Slurry Transportation at Weir Minerals Netherlands BV comments: “Pressure pulsations are an undesired phenomenon in pumping installations for a number of reasons that include damage to the pumping system, piping and supports; disturbing noise levels; and even safety risks for operators and maintenance personnel.” Weir Minerals has an advanced solution referred to as the VZ Pulsation Free system on its GEHO ® piston pumps, which it says will prevent virtually any pressure pulsations from occurring, rather than merely reducing the already existing pulsations. “Ideally the best way of dealing with the phenomenon of pressure pulsations is to prevent them from being generated in the first place. This can be achieved by creating a constant discharge fl