At the BHP Billiton Mitsubishi Alliance coalmine 24km south of the town of Blackwater, Queensland, a Grundfos wastewater pump has been operating almost faultlessly for seven months.
The open cut mine, opened in 1967, produces up to 14Mt of coking and thermal coal a year for Australia and export to Asia, Europe, the Middle East, the Americas and India.
Dowdens Pumping Sales and Services of Mackay provided the submersible wastewater pump on a two-week trial basis after the BHP Billiton Mitsubishi Alliance was unable to immediately secure a pump to match the other three pumps in the ROM.
The 26kW Grundfos pump replaced one of four 30kW pumps of another brand.
Despite being smaller, it pumped at a higher rate, with a slightly increased head pressure, and consumed less power. It was so successful that the company purchased it at the completion of the trial, and left it in place.
The pump was installed in the worst position in one of the mine’s most troublesome ROMs pumping grit, gravel, coal and coal dust, and dirty water.
The pump had virtually double the life expectancy compared with the other three pumps in service, and proved so effective that more Grundfos pumps have now been purchased.
Dowdens Pumping Sales and Services’ Mike Brewer says the other pumps appear to have failed because of motor failure and the volute impeller oil housings wearing out.
“But the Grundfos unit, which is fitted with Smart Trim, showed little wear in the time that normally elapses before rebuilding is required,” Brewer says.
The benefits to the mine have been many. In addition to saving power and getting an improved performance, the Grundfos wastewater pump design made maintenance substantially quicker and easier, while the capital cost was lower than the pumps it replaced.
Northern Coal processing plant maintenance co-coordinator/planner Derek Wilson describes the wastewater pumps as “just about bullet proof”.
Wilson says the pump has definitely proved itself. Proof of this, he says, is that the plant operators keep asking when the other pumps are going to be replaced with the Grundfos.