Mechanical Technology January 2016

⎪ Special report ⎪

Columbus Stainless: A plant tour

MechTech takes a tour of South Africa’s Columbus Stainless plant in Middelburg and talks to Lucien Matthews (right), the company’s CEO.

F ounded in 1966 in the heart of the chrome- and coal-rich Mpumalanga province of South Africa, Columbus Stainless is Africa’s only producer of stainless steel flat products and one of the few inland stainless steel plants in the world not connected to a major waterway. “This site was built in close proximity to chrome resources and low-cost power,” begins Matthews. “While this disadvan- tages us with respect to the logistics of getting finished product out, we have easy access to raw materials and we can run on very low raw material stocks,” he says. Today, global stainless specialist, Acerinox holds a 76% shareholding in Columbus Stainless with the balance (24%) being held by South Africa’s Industrial Development Corporation (IDC). “Our plant is a technologically advanced, fully integrated, single-site operation. This gives us flexibility to ad- just quickly to changes in the market,” Matthews points out. At the starting point of the stainless steelmaking process is stainless scrap.

“Stainless is the greenest of materi- als, with 78% being recycled at the end of a stainless product’s life,” Matthews says. “In our process, we melt scrap, then add some chrome, nickel and other metals, according to the alloy recipe being made. Eventually, this is converted into sheets and strips that are stamped, pressed and welded to make a host of different products: for hygienic preparation surfaces and storage systems; utensils and containers for almost everything that we eat or drink; stainless steel components in critical areas of motor vehicles, such as exhausts, airbag gas cylinders and catalytic converters; and for decoration, signage, shop fittings, architecture, fur- niture, appliances and modern technolo- gies such as hydrogen fuel cells. into the plant for re- processing into new sheets – and there is no limit to the number of times this can be done,” he reveals, adding that this is not just hearsay: the lifecycle of stainless steel has been well documented through studies at Yale University, for example. Stainless steel scrap is a high value commodity for all stainless “Goods manufactured in stainless steel have a life of 15 years or longer. Then, after this time, the steel comes back

At the heart of the 100 t electric arc furnace (EAF) is a sophisticated in-house-developed control system, which delivers composi- tional control that is among the best in the Acerinox Group. manufacturers and, while Columbus uses as much as possible from local sources, significant quantities of stainless steel scrap is imported because there is not enough in South Africa. “We also make stainless steel by melting carbon steel scrap – sourced from within SA – and then blending that with chrome and nickel as required,” Matthews adds. Scrap and ferrochrome Stainless and carbon steel scrap is accu- rately sorted into grades in the stockyard, where overhead cranes – connected to the company’s in-house order manage- ment and material flow software system – weigh and load the required grades into baskets for delivery to the 100 t electric arc furnace (EAF). At the same time, hot molten fer- rochrome (charge chrome) is trans- ferred from Samancor’s Middelburg

A basket of raw materials ready to be loaded into the electric arc furnace for melting.

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Mechanical Technology — January 2016