Integrated Pump Technology is the official distributor of Grindex pumps in sub-Saharan Africa.
According to Justin Bawden, key account manager at Integrated Pump Technology, the submersible Grindex Bravo pump is best known for operating in a liquid environment. In this case, however, it needed to be used as a booster from the wall of one of the mine's settling dams.
"The distance from the settling dam to the collection pit was about a kilometre, and the fluid being pumped was high in solids," he said. "This meant that we needed to boost the pressure considerably from the dam wall. The solution therefore needed to consider both the abrasiveness and the specific gravity of the slurry."
He noted that the previously installed pump was a normal dewatering pump. It had failed due to the extreme wear from the heavy sedimentation in the mine's settling pond.
In a solution developed in collaboration with Integrated Pump Technology, the mine submerged one of its existing Grindex Bravo pumps in the settling dam. This unit pumps into a 5in (12.7cm) pipeline over a distance of about 30m at a head of 8-10m to the newly supplied Grindex Bravo 800 at the top of the dam wall.
"We dry-installed the new heavy-duty Grindex Bravo so that it could receive material from below and boost it to the collection pit," said Bawden. "It was vital to provide sufficient pump capacity so that sediment did not block the pipeline."
He highlighted that the heavy sedimentation in this application required a fit-for-purpose slurry pump like the Grindex Bravo 800. With its impeller and pump housing made of Hard-iron, the pump was able to provide the high wear-resistance required.
"The sand and stones in the slurry would quickly cause extreme wear and cavitation inside a normal dewatering pump, which is usually made of cast iron," he said. "The large throughlet of the Bravo pumps also allows them to handle solids of varying sizes."
With a rated output of 45kW and a shaft speed of 1,475 rpm, the Grindex Bravo 800 can deliver an output of almost 100 litres per second in this application. In addition to the pump's thermal protection to avoid overheating, an optional cooling jacket on the pump can be fitted for use in dry pit applications.