Geratech smelts tin with scrap aluminium
South African company Geratech has developed an aluminothermic process under the name ThermiTin to smelt cassiterite to high purity tin using aluminium from waste cans as a reducing agent instead of carbon.This highly exothermic reducing reaction, also known as the Goldschmidt process, is commonly used for producing feroalloys or welding railways tracks together.
The process was demonstrated for tin by Russian scientists in 2021.Geratech has positioned the technology in the context of artisanal mining in Africa, where electricity supplies may be limited. By using chemical energy from the reaction, external electrical energy input is minimised.
The process has been designed inside mobile, modular plants that can be used for localised on-site processing, minimising site impact, and reducing ore transportation.In an associated green innovation, the company has developed a cost-effective mechanical pulverisation process to produce aluminium powder from used beverage cans (waste).
South Africa has one of the highest recycling rates in the world for aluminium cans. Powder from this process would supply the cassiterite processing units.There is some way to go before highly innovative solutions like this can demonstrate viability at scale, but this intriguing new approach appears closely aligned with the tin industry’s need for future sustainable technologies.
