On-site testwork at a South African base metal refinery allowed Multotec to prove its sievebend solution for improving the quality of the customer’s product to market.

According to PJ Pieters, process engineer at Multotec, the refinery was looking for the most efficient way to reduce impurities to less than 200 parts per million in the product stream.

“As the contaminants were found mainly in a specific size fraction, the aim was to remove this fraction by classification using a sievebend,” says Pieters. “To test this proposal, we used our mobile sievebend test unit which we could take onto the customer’s site and link up to one of the product streams in the plant.”

This provided a convenient way to conduct testing under normal plant operating conditions. It also meant there was no need to remove any valuable mineral product from the site, which could demand onerous security compliance procedures. The tests took only a week to conduct, after the mobile units were installed.

“The tests were conducted to reduce impurities and to measure the effect of the sievebend on the downstream screen scroll centrifuge,” he says. “We managed to achieve the product quality goal, while also maintaining optimal centrifuge performance in terms of the customer’s product moisture requirement.”

The addition of a sievebend to the process will not increase the energy costs as the machine is operated under normal gravity conditions and is compact enough to fit inline between existing process equipment.

To withstand the highly corrosive application, the sievebend and its housing were manufactured in stainless steel. By using appropriate sampling techniques, the testwork was able to deliver very representative results. This gave the customer an accurate expectation of the precise results that a full-scale installation would deliver.

“This kind of testwork adds confidence to the customer’s decision to invest in a specific solution,” Pieters says. “It is also part of Multotec’s contribution to continually improve customers’ process efficiency; we work to provide the customer with the best knowledge and products to optimise their plants.”

Another element of the valued added by the sievebend, says Pieters, is that the refinery is likely to save on potential penalties arising from impurity levels in the saleable product. Multotec also provides after-sales optimisation and support to ensure on-going benefit from the innovations applied.