Harmony Gold Kusasalethu Plant Filtration Skid Unit Success

Harmony’s deepest mine at 3 388m – Kusasalethu – is situated on the West Wits Line near Carletonville in South Africa’s Gauteng Province. At Kusasalethu, the focus is on safety as well as aiming for operational excellence.

The Kusasalethu plant makes use of rom ball mills where the fine grinding of raw material is required. During operation the rom ball mills, like SAG mills, utilise coarse rocks in the rom feed as grinding media. The mills operate on slipper pads (white metal pads) and require constant lubrication film between the mill’s drum and pads.

The reliable operation of equipment – such as rom ball mills – are vital to the efficient and effective operation of any mine as it has a direct impact on profitability. With this in mind, and due to the lack of filtration on the mine, the forward-thinking Kusasalethu team, together with FloSolve designed a filtration skid unit, geared towards reducing maintenance costs and minimising unscheduled downtime.

Prior to the installation of the skid, FloSolve conducted a sample test in order to obtain a baseline on the cleanliness level. A baseline sample is used as a reference or starting point to monitor oil condition, verify cleanliness and compare any subsequent tests. This will provide an immediate indication if there is a problem. The sample test returned a cleanliness rating of “ISO **/**/**” – an alarming indication of higher than normal contamination present in the oil. Therefore, a Mill Oil analysis could not be conducted.

High contamination levels in oil give rise to several issues, ranging from unplanned equipment downtime and maintenance costs to an increase in operating costs and premature equipment failure. It is therefore essential to monitor and maintain cleanliness levels of components to maximise machine productivity and component life.

Cleanliness is an important benefit that is derived from the filtration skid unit.
Paired with a strict maintenance schedule, the impact of a
filtration skid unit is almost instantly noticeable.

Harmony conducted preventative maintenance on a weekly basis since the installation of the filtration skid unit. This resulted in the oil analysis report averaging a cleanliness rating of ISO 20/18/15. The cleanliness of fluid is measured according to the ISO 4406:99 cleanliness code rating standard. At 14 µm particles per Milliliter, it improved from 160 000+ particles to an average of between 160 to 320 particles per Milliliter.

Since the installation of the skid unit at Kusasalethu, no unforeseen breakdowns and call outs were reported. Breakdowns and maintenance can raise health and safety concerns as technicians often rush to fix the problem and take risks in doing so. With a reduction in the mill’s costly downtime and unforeseen breakdowns, technicians are well-rested and can spend more time with their families.

For more information on PALL filtration skid unit solutions contact FloSolve on +27 (0) 11 389 5300 or sales@flosolve.co.za