The installation of a FLSmidth KREBS millMAX™ pump at Namawka Diamonds’ Kao mine, in Lesotho, is, according to the mining equipment maker, providing the miner with significant cost savings through increased impeller, casing and back liner wear life.

FLSmidth’s engagement at Kao started when the mine required a pump conversion in the field – an undertaking that can be difficult and time consuming, according to the mining OEM. “It is also a high-stakes operation as a cyclone feed is critical to the overall process and ability to generate returns. A wrong decision can mean a lot of lost revenue,” the company said.

It was the potential for cost efficiency that convinced Kao diamond mine to implement the KREBS millMAX Pump. After initial discussions, the first trial pump – a millMAX 8×6 centrifugal seal (C/S) – was installed in a cyclone feed application (DMS 2 pump 1).

Initial results after seven months showed the millMAX was performing extremely well on the wear side, according to FLSmidth.

“So, once you get the green light, you need to confirm the duty details and measure up the existing installation to ensure that when you begin to install the pump there are no surprises,” the company said.

Brad Moralee, Head of Product Unit Pumps, Cyclones and Valves at FLSmidth, said: “It’s high pressure for us: you are typically given a window of opportunity during a shutdown to complete the change, after which the new pump must run as expected when the plant is re-started.

“You need the combination of a great product but, more importantly, great technical understanding of the duty to be able to propose the correct solution. We understand what is at stake from the customer side.”

The change produced impressive results in comparison with the previous solution from another supplier, according to FLSmidth, with the millMAX increasing the wear life by nine times, across impeller, casing and back liner. “This has seen Kao make significant cost saving on direct replacement costs, reduced downtime and saved labour expenditure,” the company said.

While Kao mine operators were impressed with the benefits from the switch, a slight gland leakage was causing concern, according to FLSmidth. To resolve this, FLSmidth suggested running a one-month trial with the slurryMAX, which had just recently arrived on the South Africa market.

“The slurryMAX trial was based purely on its sealing capabilities as Kao were confident of the hydraulic performance of the pump and had no concern about wear as they were confident the slurryMAX would show predictable and even wear life across all wet-end parts,” the company said.

Kao’s confidence also came from the fact the slurryMAX design is based on the millMAX range, whose wear ring technology has created an efficient and long-lasting slurry pump.

The main difference between the millMAX and the slurryMAX is that the millMAX is an all-metal pump meaning it does not have an outer casing and an inner wear liner (the casing itself is made from the high chrome wear material), while the slurryMAX is a split casing design that has a replaceable inner liner. The purpose of this design is that multiple material liner options are available to fit in the same outer casing.

“The slurryMAX features an improved, more efficient impeller and an optional water drain plug for easier maintenance, allowing water that might have settled at the bottom of the pump to be drained quickly,” the company said.

Leigh Rieder, FLSmidth Sales Engineer, concluded: “Kao is extremely happy with the hydraulics and lack of excessive wear of our pumps, which has meant that their cost of ownership is low. We have recently received an order from the customer for two more slurryMAX pumps and they have expressed interest in our slurryMAX 6×4 and slurryMAX 10×8 pumps.”