Lee Vine, managing director at Integrated Pump Rental, said that attempts by the mine to desilt the main process tank using different methods of dredging had proved inadequate and the challenge of this reservoir continuously filling with slurry remained a concern, especially with regards to storage capacity. In addition, the silt build-up was causing damage to the process pumps, resulting in unscheduled downtime and unnecessary maintenance expenditure.

Initially, Integrated Pump Rental proposed a SlurrySucker rental unit as this was deemed the quickest solution. However, there were also some reservations on the part of the mine due to failures with other equipment. The rental unit was installed on the main process tank for a trial period of two weeks.

The SlurrySucker dredging unit was required to pump 250m³ of mixed material out of the 40m-diameter, 8m-deep process water tank. This translates into 60t of dry material per hour.

Vine commented: "The performance of the SlurrySucker in that initial two week period was so good the mine made the decision to purchase its own unit. Our equipment quickly proved itself capable of dealing with the silt issue, and keeping the level of the main process water tank within acceptable parameters."

Vine said that the SlurrySucker, which is equipped with a Grindex Bravo 700 submersible pump, suited the mine so well because of the mobility it offers. He concluded: "The unit can be moved from one tank to another, facilitating desilting of all process water and other water storage tanks and dams ensuring these remain fully operational and silt free."