Modern Mining April 2021

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both greenfields and brownfields installations. The Warman WBH pump offers lower mainte- nance, lower power usage, longer wear life and better performance when compared with previous horizontal slurry-pump technology. A key feature is the one-piece frame for correct alignment of bearings, seal and impeller to front liner, a feature also present in the very successful Warman DWU dewatering range. The pump incorporates a fully adjustable and rotatable throatbush to spread the wear more evenly and maintain high levels of per- formance for longer periods. Ease of maintenance and safety typically go hand in hand, says Koorts. “All our pumps are designed with ease of maintenance in mind. The easier the maintenance, the safer the pump becomes,” he says. On the Warman WBH pump, for example, the ‘One Point’ front liner adjustment feature allows both rotational and axial movement to minimise the front impeller gap which, in turn, reduces wear and main- tains performance. Significantly, this adjustment can be made while the pump is running, eliminating the need to stop production, which results in cost sav- ings for the plant. Another key factor in the pump selection process is the reputability of the supplier and their ability to offer different types of pump from a single sta- ble. With 150 years of engineering expertise, Weir Minerals’ comprehensive range of pumps includes a solution for every application, from centrifugal slurry pumps, piston diaphragm and hose diaphragm to positive displacement, peristaltic, vertical, submers- ible and mine-dewatering. Koorts also notes the importance of choosing a pump type that is suitable to the application and sys- tem objectives. For example, the role of a filter press in recovering valuable saleable product makes it an important consideration for a mine operator, and just as important is the selection of the most appropri- ate pump for this application. Weir Minerals Africa has the expertise to advice on the best selection and offers a wide range of suitable pumps. “As a mission-critical system in the mineral concentration process, the filter press demands a carefully selected pump to ensure optimal per- formance and uptime. The role of a filter press in recovering valuable saleable product is an impor- tant consideration for a mine operator. The low back pressure on startup, followed by the high pressures associated with operating a filter press, however, often cause the pump to underperform. The oper- ation of a filter press involves a wide spectrum of pressure and flow conditions within each cycle. This ranges from high-flow, low-pressure conditions when slurry is initially being pumped into the press, to low-flow and high-pressure when full.”

Valves Weir Minerals offers a wide range of valves, including Isogate knife gate valves for moderate slurry appli- cations, Delta Industrial knife gate valves for severe service applications and Isogate pinch valves. The company’s Isogate and Delta Industrial knife gate valves are designed to handle tough slurry applica- tions while also ensuring ease of maintenance. Searching for the right valve for your applica- tion is no easy task and depends upon a number of variables. A valve application may be for isolation, control or safety. Once it has been determined what the operating requirements are, it is vital that the valve selection is based on accurate process infor- mation. In a mining operation, there are a number of different processes where the valve selection may vary, including type of media, size and shape of solid particles, pressure, temperature or chemical content of the slurry. Diphare notes five key factors of significance when selecting the right valve for the application. Firstly, it’s the application itself. The mill circuit, for

The Warman mill circuit pump installed in a copper mining application.

Isogate valves installed in a Cavex hydrocyclone cluster intended for a gold mine in Africa.

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April 2021  MODERN MINING  21