Modern Mining April 2021

PUMPS AND VALVES

Choosing the right pumps and valves for The selection of correct pumps and valves is critical to the ongoing operation and efficiency of the plant, safety of personnel and the environment. Traditionally considered an afterthought, the choice of these components – which keep corrosive and abrasive fluids flowing – depends upon a number of factors. By Munesu Shoko .

L ike any other piece of equipment, pumps and valves play a critical role in the overall efficiency and safety of the mineral processing plant. Yet, the selection of these components – which

Joseph Diphare, senior applications engineer valves at Weir Minerals Africa. other ancillary equipment, but a critical component of the plant. “A valve failure can have devastating effects on the plant and the environment surrounding it. Failures can result in unwanted plant stoppages, incur high maintenance and repair costs and pose serious safety and environmental challenges on site, specifically in acidic applications,” says Diphare, add- ing that the cost of a valve is negligible compared with the cost incurred by a plant stoppage. Given that pumps and valves used in mining appli- cations are subject to some of the harshest and most demanding conditions, Diphare and Koorts reiterate the importance of selecting the most appropriate components for each specific application. There are a number of factors to consider in selecting and con- figuring pumps and valves. Pumps A principal factor in the selection of pumps, says Koorts, is energy efficiency. A typical plant, he says, consists of one or two mills, one or two large clus- ters of hydrocyclones, and hundreds of pumps. Pumps generally consume a lot of energy. The larg- est power consumer in a typical plant setup is the furnace, followed by the mill and then the pumps. In some coal plants, the largest consumer of power can be the pumps themselves. To provide context, Koorts says Weir Minerals did a survey at a small coal mine where the installed power was 2 MW, and pumps alone consumed 1,6 MW of the installed capacity. In fact, Weir Minerals, from a pumps point of view, offers three value propositions: efficiency, safety and ease of maintenance. Through continuous research and development, Weir Minerals today offers some of the most efficient pumps in the industry, says Koorts. A case in point is the prominent Warman® range of centrifugal slurry pumps. The Warman® MCR® pump is typically used in heavy-duty appli- cations such as mill discharge, slurry transfer and process pumping applications, and is suitable for

Marnus Koorts, product manager pumps at Weir Minerals Africa.

depends upon a number of variables – has tradi- tionally not received the required attention in many instances. In mining, what matters most is the overall cost per tonne to deliver the product. Marnus Koorts, product manager pumps at Weir Minerals Africa, is of the view that the economic efficiency of the mining process hinges on the overall efficiency of all pieces of equipment deployed across the whole system, including pumps. “Pumps are the heartbeat of every plant,” says Koorts. “Without them, nothing gets transported from one process to the other within the system.” Motshumi Joseph Diphare, senior applications engineer valves at Weir Minerals Africa, says min- ing customers realise that a valve is not just like any

The Warman AHF pump, one of the large range of pumps, is very successful in froth and past applications.

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20  MODERN MINING  April 2021