TEXT & PHOTOS: Chris Wyper
The Kanmantoo copper mine in South Australia was constructed in 2011, combining new equipment with refurbished equipment from the Pillara Mine located in Western Australia, which closed in 2008.
Kanmantoo’s tailings storage facility (TSF) is at a higher elevation than the Pillara plant, so a new design was required to include additional tailings disposal pumps. Once commissioned, severe wear issues were discovered, which caused regular downtime for the whole operation. During the first year of operation, the cost of maintenance exceeded one million dollars. The hardness of the garnet was believed to be the major source of abrasive wear together with the high head per stage.
“When the wear life of the pumps is just 120–200 hours, it’s nothing. That’s a total of only ten days. So, every ten days, we had to dismantle and then rebuild the pumps, spending a lot of money each time,” remarked Greg Craddock of Hillgrove Resources.
“In the first year alone, the cost of running such high-wearing pumps was costing a fortune. Performing the maintenance was also a very time-consuming task. Up to 10% of our maintenance effort was spent on this one problem, requiring a day’s work from three to four people,” he continued.
Several unsuccessful approaches to improve the wear life were tried at the Kanmantoo operation. Researching the market for available solutions to their problems, Hillgrove Resources reached out to Metso. After conducting a series of trials, the team determined that the fault was not with the pumps, but the system itself.
Moving from two stages to three
It is common practice to share the load across several pumps, or stages, when pumping at high heads. The total head is divided among the number of stages. In the initial design at Kanmantoo, there were only two stages. After encountering the numerous operational issues, it was agreed to trial a third pumping stage.
Taking charge of the stock
Besides the technical solution, the Metso team took care of the mine’s consignment stock so that Kanmantoo could have stock of wear parts in its inventory permanently.
This demonstrated Metso’s commitment to the customer in providing long-lasting support. The mine is now also reaching out for a Metso solution when any crushers, screens or other mineral processing equipment requires support.
Today, because the Kanmantoo mine is lifting the tailings dam, the number of pump stages has increased from three to four, and a fifth stage is to be commissioned in early 2016. For Greg Craddock, the choice was obvious, “We really like using the Metso pumps. The fitters think the hydraulic slidebase is fantastic, and the Metso team has given us the support we need.”