MechChem Africa July-August 2023

⎪ Cover story ⎪

Two new testing laboratories To raise the bar with respect to safety, qual ity and customer satisfaction levels, Weir Minerals has established two new laborato ries to further its world-class manufacturing capability. “We have equipped these labs with the latest technologies to align our manufacturing operations with global best practice standards. A focus on quality as surance through the manufacturing process ensures good quality products and investing in upstream quality assurance has been part of the reliable supply success. Quick results mean the operation team can fine-tune the manufacturing processes, catch any discrep ancies and implement changes very quickly. This helps us to optimise product availability and on time delivery,” he says, adding: “it gives customers a great deal of confidence in terms of product quality, lead times and supply cer tainty, while also reducing waste, rework and time lost repairing manufacturing defects.” From a competitive point of view, the laboratory facilities also support research and development in improved equipment and materials, which further benefits customer operations. “By keeping our testing in-house, we are better able to protect our intellectual property. I think the other spinoff from this is that it contributes to skills development, encouraging staff to improve production processes and quality standards. It helps us to build-in a continuous improvement culture,” he adds. Water harvesting A further aspect of Weir Minerals’ drive to implement its global sustainability goals is that water harvesting has been implemented in all its South African manufacturing facili ties. “Water used in our facilities is now being collected and reused in various other areas of the plants. At Isando, for example, where we need a lot of cooling water in the rubber shop, instead of having to draw on municipal water

Govender informs MechChem Africa . A polystyrene replica of a casting is made first. This is then dipped several times into a ceramic-forming slurry to coat the surface. The coated polystyrene replica is then fired, which hardens the ceramic while completely removing the polystyrene, creating a very accurate ceramic shell that, when supported by sand, is used as the mould for casting. Because it is inert, the ceramic shell reduces the possibility of hydrogen defects, while also significantly improving the as-cast accuracy and surface finish of the product. The Replicast process eliminates parting lines, cores, and draft angles from the com pleted casting, which reduces casting weight and fettling requirements. It also reduces machining requirements on a finished casting. Furthermore, the risk of gas, sand inclusions and hot-tear defects are significantly reduced. Combined with the improved moulding pro cess, new Integrex Industry 4.0 machines have further improved machining efficiencies. “Our Replicast plant has reduced the com ponent turnaround, improved casting quality and reduced waste. Also, though, it further reduces the energy requirements and our carbon footprint,” he adds. Because molten metal is no longer in direct contact with the casting sand, the Replicast system does not require the use of resin and catalyst for binding the supporting sand. Instead, Grade 30-35 AFS silica sand can be used which, prior to being compressed, is first passed through a vacuum bin to remove any air. And because the sand contains no acids or resins, it can be reused many times, which results in further environmental and sustain ability advantages. “In addition, the new system releases fewer harmful gases into the atmosphere during the casting process, further helping us to meet our corporate sustainability goals and to reduce environmental impacts,” says Govender.

for this purpose, we can use collected and recycled water from the plant. And in the HBF plant in Port Elizabeth, which is a water scarce region, we have installed larger collection tanks to store more rain and recycled water, all of which is fully utilised in the facility,” says Rajen Govender. “Our three local manufacturing sites enable us to deliver locally manufactured pumps and, depending on the application, product mix and customer’s installed base, we can typically claim between 60 to 80% local content for South African mines. “We have very deliberately expanded our integrated solutions approach so we can offer solutions for everything from after blasting to tailings, including highly efficient processing solutions, such as our Cavex ® hydrocyclones, Trio ® crushers and Enduron ® HPGRs. “We are committed to the sustainable and efficient delivery of the World’s need for natural resources from African mines, and to a better and greener future for our planet,” Govender concludes. www.global.weir

The large screen test bay at the Alrode facility for testing locally manufactured large vibrating screens.

Left: Weir Minerals Africa has also installed a Replicast plant at its Isando facility for manufacturing casting moulds. Right: Edward Motha presents rubber testing results from a Weir Minerals Testing Laboratory in Isando.

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