China’s Zijinshan mine turns waste into roads that withstand 100-ton trucks

A gold and copper mine in Longyan, China, has shown that its own waste can become the road beneath its heaviest vehicles. According to ‘Sustainable valorisation of mine-derived solid wastes into cementitious pavement materials: Mechanical performance and microstructural insights,’ researchers mixed blasting slag, neutralised dreg and a binder made from steel slag, waste cement and lime slag, all taken from the Zijinshan Gold-Copper Mine, then laid test roads that carried 100-ton trucks. After 28 days, the best mixture resisted deformation better than rock, soil and plain blasting slag, and it met groundwater limits for three toxic metals. This article explains how the mixture works, what the field tests found, and what limits remain, using a recent study.Why open-pit gold mines in China need stronger haul roads and a better use for stockpiled mine wasteOpen-pit mining generates large volumes of solid waste, including blasting slag, waste rock and treatment residues, which need extensive land for disposal and storage. The roads that carry ore are also under heavy strain, because they face intense rainfall, wind erosion and flooding while taking repeated heavy loads, which leads to p...