MechChem Africa talks to Weir Minerals Africa’s pumps product manager, Marnus Koorts, about the extensive depth and range of pumping solutions available through Weir Minerals and its widely experienced and qualified teams; and the company’s successful approach to meeting the long-term needs of mine and process plant operators.
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“As well as our extensive range of slurry, dewatering and speciality pumps, we pride ourselves on developing innovative and reliable engineered-to-order pumping solutions that offer the best possible energy efficiencies, at the lowest-possible total costs of ownership,” begins Koorts.
Since the invention of the Warman® slurry pump with replaceable liners more than 80 years ago, Weir Minerals has develop its technologies and boasts some of the most modern and innovative slurry pumping solutions in the world. In addition, through acquisitions and mergers, the company has accumulated and redeveloped a vast range of pumping products for transport and processing applications across the mining and minerals processing sectors.
Starting with the Weir Minerals’ slurry pump ranges, Koorts says the key to innovation and development of slurry transport solutions is strong lifecycle support. “Through consistent and high investment in research and development, we have been able to successfully extend wear life, reliability and total life of our slurry pumps to minimise pumping and plant operation costs. Coupled with this, we have put in place highly sophisticated spares and aftermarket support services for plant operators’ convenience,” he tells MechChem Africa.
“Our Warman AH pumps are still the world’s most widely used slurry pumps, but even these receive ongoing research investments to maximise their performance. Continued innovation makes this range increasingly productive, efficient and reliable, with longer wear life and easier maintenance. Condition and demands at mining sites are increasingly harsh, while the slurries present widely varying challenges, so even our highly successful products are continuously improved,” Koorts continues.
Also integral to the company’s slurry pump offering are:
- Weir Minerals’ metal- and rubber-lined Warman® (MCU® and MCR®) mill circuit pumps, which include some of the largest pumps available for mill circuit duty.
- Vertical spindle pumps for clearing sumps and spillages.
- Carbon transfer pumps for carbon in leech (CIL) circuits, which are carefully designed to gently recirculate the carbon slurry so it doesn’t break down.
- Warman® AHF froth pumps, used for removing the froth from flotation circuits and also ideal for stirring up thickened underflows to improve pumpability.
- GEHO® high pressure positive displacement pumps offer pumping capacities of up to 800 m3/h in some applications at discharge pressures of up to 250 bar. “These pumps can handle 85% solids content when required, which makes them ideal for use with our Isodry® range of filter presses and thickeners for making tailings as dry as possible,” Koorts says.
Moving on to Weir Minerals’ dewatering pump range, Koorts notes that dewatering is, in general, particle or slurry free. “The key focus for dewatering is high pumping efficiency to reduce energy costs per volume pumped. Dewatering often involves very high heads for pumping water from deep pits or underground mine shafts due to continuous water seepage.
“Mines usually use process water and they need to maintain their water balance. The water used must be filtered, cleaned and recirculated. Every one of these water circuits is different, so we offer customised water circuit solutions to meet specific site needs at the highest possible energy efficiency,” he informs MechChem Africa.
Weir Minerals can offer horizontal, vertical spindle and multistage pumps from its Multiflo®, Floway®, and Warman® brands, depending on the specific need. “We also offer a range of dirty water and submersible options, many of which are portable so they can be temporarily placed into flooded areas until the unwanted water is pumped out and then moved somewhere else,” he explains.
“Our Warman DWU dewatering pump has been further developed to enhance our high head mine dewatering. These pumps can handle dirty water with densities of up to 1.05, that is, water with low solids content. Underground mine water often starts out ‘clean’ but particles tend to accumulate over time, so we have evolved the ‘hybrid’ dewatering solution to cater for this,” Koorts explains, adding that the Warman® DWU pump’s bearing assembly deals with load variations, while its slightly wider throat bush and impeller tolerances enable solid particles to pass through easily.
From Weir Minerals’ speciality pump range, Koorts goes on to highlight the company’s Lewis® range of chemical pumps, which are widely used in copper leeching circuits. These pumps can cater for the production, transfer, and processing of sulphur from its points of production (from mineral or hydrocarbon sources) to the major points of use in sulphuric acid plants.
Adding depth to each of its brands and product ranges, Weir Minerals has a dedicated materials division that develops wear and corrosion resistant solutions for the vast range of pumps and applications needed by the company’s diverse client base.
“Our original Ultrachrome A05 metal alloy, developed in the 1990s, is still widely used for metal wear parts such as throat bushes and impellers in mill circuit applications, but we have developed additional materials such as Hyperchrome A61 and, our latest addition, Hyperchrome A68, a patent pending alloy that is showing improvements in wear life of as much as 30% in mill discharge for specific applications,” Koorts says.
For specific corrosive media, stainless steel variants are available, and different special alloys have been developed for when corrosion and abrasion resistance are required – and new and customised materials are continuously being worked on.
“It’s not just about metal. Our R55 rubber is the standard rubber material used in the Warman pump range, but we have also applied valuable materials technology expertise from Linatex rubber into our pump ranges and, for SO2 and acidic applications, we have specific synthetic rubbers that are capable of handling solids in these acidic environments,” Koorts reveals.
“Our entire technology division works in an integrated way to incorporate new materials and design enhancements into every product range. There are many examples of failures in the market. Before we release a component or material change, we go through rigorous testing processes all over the world to ensure there are no unforeseen consequences,” he assures.
In terms of expertise, Koorts notes that Weir Minerals’ engineering staff have extensive experience across a broad range of applications: from slurry pumping to dewatering and from mill circuits and flotation cells to copper and gold processing plants. “As a result, we know how a change in one part of a mine will affect the other parts and we are able to develop holistic and integrated solutions,” he says, citing one case where a problem with a mill pump was resolved by completely redesigning the sump and the inlet piping: using Computational Fluid Dynamics (CFD) to optimise the inlet flow to reduce abrasive wear on the inlet lining of the pump. “We strive for complete engineered solutions rather than simply relying on high quality pump products to deliver,” he notes.
Weir Minerals’ floating pumping stations for pit dewatering are another engineered example: “These systems include all the pumps, valves, hoses and controls required to dewater dams from floating pontoons. They are integrated products developed to solve specific site problems and are engineered to be fit-for-purpose using suitable products from our range,” he says.
Weir Minerals’ considerable success with this engineered approach is evident from the £100-million order from the Iron Bridge Magnetite Project in Australia. “This is Weir’s largest ever individual mining order. It comprises a range of our crushing and pump equipment including Enduron® High Pressure Grinding Rolls, and GEHO® pumps that will reduce energy consumption and wet tailings waste by more than 30% compared to traditional mining technologies,” Koorts tells MechChem Africa.
Success in projects such as these requires an excellent supply chain with a massive infrastructure. “We have the infrastructure, logistics and connectivity to get equipment to the most remote sites in Africa, a feat that can be problematic if a supplier does not have the required capability and footprint.
“We have the engineering, manufacturing, product range, spares and supply chain to back up every product and every engineered solution we offer. That is why we are the global leaders in pumps, with a market share larger than all our competitors combined.
“Getting pumping solutions consistently right for over 80 years does not happen accidently. It happens because of ongoing innovation, development and critical thinking into everything we do,” Koorts concludes.
