Germany: BHS-Sonthofen and MSW Mineralstoffwerke Südwest have been awarded the German Resources Efficiency Award 2016 for their Combimix process. The German Federal Minister for Economic Affairs and Energy awarded the prize to the two companies in mid-February 2017. The process uses lime to improve raw materials yields in quarries contaminated with clay.

BHS developed the Combimix process based on their twin-shaft batch mixers and implemented it together with MSW. It uses lime to mix with clay that then undergoes a chemical reaction and this allows it to be separated from the rock in a subsequent processing step. The process allows more materials, such as limestone, to be extracted from quarries and extends the usable lifespans of such sites. In addition, previously dumped materials considered unprofitable can now be reassessed.

MSW introduced the process at its Mönsheim quarry in the summer of 2016. It allowed the company to increase its repository’s yield by 25%. To produce the same volume of the final product, it was previously necessary to extract about 620,000t/yr of limestone. At present the total is around 188,000t less, which corresponds to a relative reduction of around 30%. It helped to increase raw material efficiency from the previous level of 65 – 70% to around 93%.

“Our Combimix process holds a vast potential as it enables companies across the globe and throughout various industries to utilise resources more efficiently. In the context of rehabilitating contaminated soil, Combimix can be used to remove oil and other harmful substances. As a result, only a small fraction of the feed material needs to be dumped in hazardous waste landfills. The process is also viable for the cement industry. Here, it can be applied to processing limestone, a key ingredient that improves the burning process in rotary kilns and thus contributes to reducing fuel consumption,” said Dennis Kemmann, the managing director of BHS-Sonthofen.