Integrated Pump Rental’s innovative SlurrySucker desilting barge is successfully cleaning a large process dam for a coal mine in Mpumalanga, after past attempts by numerous contractors had failed.

The dam – at a mine in the Delmas area – measures a substantial 300 metres by 100 metres in size, with a six metre depth. It was unable to function effectively as it had become 90% filled with coal slurry from the processing plant. Ruaan Venter, rental development manager at Integrated Pump Rental, says the pond is also lined with a geomembrane to prevent the coal slurry from contaminating the groundwater.

“Manual excavation methods had been tried by previous contractors, but these could not efficiently move the required volume of sediment,” says Venter. “In fact, some attempts made matters worse by damaging the environmentally important membrane under the pond. In addition, extensive reed growth in the dam also hampered the desilting efforts.”

By contrast, the application of the SlurrySucker was able to meet the safety priorities of the mine while cost effectively removing the slurry. Operating the barge remotely from a defined distance away from the dam’s edge is much safer than having personnel or equipment on the dam itself, he says. Operators also use a buddy system with a harness for added safety. Extensive training of operators was also required by the mine before work began.

“We were able to float the SlurrySucker on those parts of the dam with sufficient water, while also employing hydro-mining on the drier areas,” he says. “This allowed our high-solids pumps to dredge quickly and cost effectively over the whole area of the dam.”

Two monitoring guns, each fed by a 7-bar high pressure discharge hose, are blasting the drier slurry towards the discharge point. Specialised pumps with chopper-impellers are employed, which can deal with the dislodged reeds without becoming clogged. After setting up on site in December 2020, Integrated Pump Rental is expected to complete the slurry removal process by the second quarter of 2021, says Venter.