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 8x6 centrifugal seal (C/S) - was installed in a cyclone feed application (DMS 2 pump 1). Initial results after seven months showed that the millMAX was performing extremely well on the wear side.“The results were extremely positive,” reflects Brad Moralee, Head of Product Unit Pumps, Cyclones and Valves at FLSmidth.

Changing out a competitor’s pump in the field, what we call a pump conversion, is a big assignment. It involves building relationships, climbing around in the sumps and dirt on site and doing technical presentations along with on the fly technical problem solving.

Brad MoraleeHead of Product Unit Pumps, Cyclones and Valves at 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.


“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.”


Thankfully for Kao, the change produced remarkable results in comparison to the previous solution from another suppli-er, 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.


Kao were impressed with the benefits from the switch but a slight gland leakage was causing concern. To resolve this, Kao again looked to FLSmidth, who suggested running a one-month trial with the slurryMAX®, which had just recently arrived on the South African 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.


Kao’s confidence also came from the fact that the slurry-MAX 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 that it does not have an outer casing and an inner wear liner (the casing itself is made from the high chrome wear material), whilst 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 implementation was smooth even though the orientation of the volute needed to be changed on site. And so far, the pump is performing perfectly with zero leakage being experienced.

Leigh RiederFLSmidth Sales Engineer
"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 6x4 and slurryMAX 10x8 pumps,” concludes Leigh.

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