GEHO's 1,000th piston diaphragm pump

Weir Minerals Netherlands has supplied its 1,000th GEHO­ piston diaphragm pump since it started the engineering and manufacturing of these pumps in 1968 for the transportation of ores, minerals and tailings. Starting initially with pumping applications that are technically described as 'simple', gradually the pumping applications have become more challenging. Pump motor ratings, capacities, discharge pressures and slurry temperatures are constantly increasing and the GEHO pump designs have been continuously optimised and further improved to meet the demands of our customers.

The 1000th pump has been installed at the Coral Bay nickel plant in the Philippines as a triplex piston diaphragm pump to feed the autoclave that processes nickel slurry under high temperatures. The pump features the proven heat-barrier concept, a special design to handle high temperature slurries under extreme corrosive conditions such as the HPAL process. Thanks to this unique technology, optimised diaphragm and component configuration have proven to meet the high reliability requirements.

The design keeps hot slurry that flows through the valve housings at some distance from the diaphragms. Interconnecting piping consists of two major components, an oscillating separator and a water-cooled jacket. Special alloys are used for all pump components exposed to the hot and corrosive slurry. Another, but no less important feature is the slide mounted pump power-end that reduces stress and prevents potential fractures due to thermal expansion of the pipes.

Ongoing development in partnership with the end-users has enabled the company to respond to the challenging needs for even higher flow rates, pressure and temperatures, whilst maintaining the high GEHO autoclave feed pump availability and low ownership cost.

With this pump Weir Minerals reinforces its worldwide experience in pumping high temperature laterite-nickel slurries. The concept is applied in pressure acid leaching at Bulong in Western Australia and selected above other pump technology at Moa Nickel in Cuba. For the High Pressure Acid Leach (HPAL) technology GEHO pumps are used at Australia's Murrin Murrin (Minara) and Ravensthorpe (BHP Ravensthorpe), at Rio Tuba (Sumitomo) in the Philippines and Ambatovy (Sheritt) to be commissioned in Madagascar.