The supply of 52 pumps by Weir Minerals Africa to Xstrata’s Goedgevonden plant in Ogies will be the largest slurry pump installation in the Mpumalanga coalfields area. In addition, the company will provide Xstrata with a maintenance and pump replacement service on all pumps.
Based on one of the largest coal plants in Australia, the Goedgevonden plant will be the largest Xstrata plant, producing 3,000 tonnes per hour of coal once completed.
“We supplied all the vertical spindle pumps as well as horizontal pumps from the 75 DMP through to Warman 14/12 F AH pumps, and this was done over a five month period to dovetail with the project requirements,” Nico Smit, branch manager Weir Minerals Africa Witbank, says.
Pumps supplied include the primary cyclone feed pumps; secondary cyclone feed pumps; primary and secondary correct medium pumps; dilute medium pumps; desliming cyclone feed pumps; spiral product cyclone feed pumps; spiral discard screen and underflow pumps; low pressure clarified water pumps as well as high pressure pumps; the thickener underflow pumps; the plant supply pumps; the return water pumps, dust suppression; the HDV defueling sump pump; and the sump or spillage pumps.
All pumps are equipped with the Warman E-Base (Efficiency Base) system. “This is the first time that the E-Base has been installed on vertical spindle pumps and essentially means that by eliminating slippage on the v-belts, significant savings in energy consumption will be achieved. In addition, it will shorten the changeout on v-belts as it is not necessary to realign the motor with the pump,” Smit says.
The E-Base was engineered to manage and reduce operating costs as well as ensure vital and realistic performance improvements in pump installations.
Smit says it is an innovative world first approach to pump v-belt drives, which ensures the correct belt tension, as specified by belt manufacturers, is applied throughout the life of the system. “Correct tensioning on the v-belt is maintained without the need for constant and continual adjustment.”
“This is achieved through the use of a simple, highly effective self-tensioning device known as the OST torsioning element,” Smit says. It consists of four precision moulded rubber mounts which store energy that is released as the belts stretch and wear.
The entire system ensures an improvement of the belt performance from between 50 to 300%. Whilst belt performance is significantly improved, the reduction of belt slippage through the correct manufacturer’s tensioning, ensures the power available at the motor shaft is transmitted with minimal losses to the pump unit.
A three year contract is also in place for maintenance on the valves as well as maintenance on and replacement of the pumps. “We will keep stock of all critical pumps and these will be changed out as conventional service exchange units,” Smit says.
The mine has made allowance for Weir Minerals Africa to have a fully equipped workshop on the mine itself. “Our technicians will be on site during normal working hours to ensure that the pump installations operate in terms of their specified performance,” Smit clarifies.
“The advantage of having a maintenance contract is that it ensures greater plant availability and allows mine artisans to concentrate on other equipment within the plant itself and not have to concern themselves with pump installations,” Smit says.