The KwaZulu-Natal-based Mathe Group, South Africa’s largest tyre recycler, has developed two steel by-products that are being exported to Australia and Korea in growing quantities.

Dr Mehran Zarrebini, head of British investment group PFE International, which is one of the major shareholders in Mathe Group, and which also owns sister company Van Dyck Floors, says that up until now, the focus has been on producing large quantities of rubber crumb.

This crumb is used to manufacture acoustic products and rubber flooring, as well as to resurface roads and provide infill for sports fields.
 
About 27% of each 68 kg truck tyre is high-tensile steel, however, and, as the plant consumes more and more tyres, the steel output also grows.
 
“We processed more than 100 000 used truck tyres in 2017,” says Zarrebini. “But, we have processed 35% more tyres in January to June 2018 than during the same period last year.

“These figures reflect in the sale of steel. We are expected to process close to 250 000 radial truck tyres in 2018.”
 
In 2017, Mathe shipped 1.5 t of steel. Between January and June this year, the company has already extracted and exported 987 698 kg of steel  – up more than 300 000 kg on the same period last year.
 
Until recently, the majority of the high-tensile steel was removed using magnets during the shredding process and then loaded into shipping containers and trucked to the Durban port.
 
Recent investment in a debeading machine that removes the main steel rim from the tyres ahead of the crumbing process, has resulted in an additional steel by-product that can be on-sold.
 
“Last year, our shredders quickly became blunt because we were processing the whole tyre. New blades are imported and are extremely expensive,” explains Zarrebini.

“This new machine removes the steel that blunts the blade before the rubber components are shredded and has, therefore, significantly reduced wear and tear and improved both output and efficiency.”

The Mathe Group has also developed its own baling machine, now commissioned. This machine compacts the steel removed from the radial tyres.

Compacting the steel enables larger quantities to be loaded into each container. As a result, each container holds about 20 t of used steel for recycling.
 
Zarrebini says demand is growing not only because countries like South Korea, which have large car and ship building industries, have an ever growing need for high-tensile steel, but also because the Mathe product is particularly clean.
 
“Clean steel which has the least amount of rubber is far easier to process. We have less than 4% rubber contamination in our product, making is far easier to process than steel sourced from elsewhere in the world,” he says.