Increasing pump wear life at a copper mine at Kanmantoo, Australia

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.”

Significant cost savings in many ways

This retrofitting project has provided numerous benefits for Hillgrove Resources, the most significant of which is the lifetime cost saving achieved. 

Since multiple pump stages were commissioned, this allowed the mine to reduce the head per stage as well as provided a wider material choice for the pumps. More efficient rubber-lined pumps were installed, bringing the lifetime of the previously failing equipment up to an acceptable level while also reducing energy consumption.

“Once we commissioned the first couple of sets of wear parts and they hit the mark of over 1,000 hours of operation, we knew we were moving in the right direction. This gave us a lot of credibility, and the relationships between the teams became even more cooperative,” says Chris Wyper, Director of Sales, Mining Flow Control for Metso, who expresses how happy Hillgrove has been with the solution. 

Wear life has improved dramatically. Currently, the life of a pump is reaching around 1,700 hours and there are plans to increase it further still. Going from metal to rubber pumps and operating closer to the best efficiency point has raised the pump efficiency from 59% to 69%. The savings in energy reduction is approximately $ 50,000 per annum thanks to a high-efficiency hydraulic design. The savings in of parts alone amounts to hundreds of thousands of dollars, along with the reduced operational costs and the improved mean time between failures. 

Due to the hydraulic slide base concept implemented by Metso at the fourth stage, the Kanmantoo mine is able to benefit from reduced maintenance time. Operations are now safer thanks to the fact that less energy is being stored, and there is less risk of trapped liners due to better alignment. 

“This is a great example of Metso’s collaboration with the customer to solve a problem,” adds Chris Wyper. “We both knew that it was going to be a long road, with many hours spent testing materials and keeping track of the results. But it was only by going through this process as partners that Metso and Hillgrove were able to best optimize the pumping system. There was also superb cooperation between everyone involved at Metso. I’d especially like to give thanks to Michael Lally for his excellent account management skills and tireless devotion to his customer.”  

The Kanmantoo copper mine

The Kanmantoo mine is a copper mine in South Australia, near the town of Kanmantoo, 55 km southeast of Adelaide. The mine is owned and operated by the Australian-based mining company, Hillgrove Resources Limited.

The current defined mineral resource of 31.3 Mt allows a throughput of over 3.0 Mt per annum, containing about 20,000 tons of copper metal and associated gold and silver, over a proposed 10-year mine life. Associated with this deposit is garnet, an auxiliary mineral, which is a very hard and abrasive crystal. This is not mined as a product, but instead reports to the tailings, or waste stream.

MORE INFORMATION: 
chris.wyper@metso.com

Published in Results flow control customer magazine 2/2015.