High-purity copper recycled from smelter dust by sulfation roasting, water leaching and electrorefining

Abstract

Metal recycling is drawing high interest in the context declining natural resources and the future circular economy. Smelter dust from copper extraction plants contains copper (Cu), which is both an economic loss and a pollution issue. There is therefore a need for techniques to recover Cu from ultrafine dust. Here we tested sulfation roasting, water leaching and electrorefining to recover Cu. We studied this process by thermochemical simulation and thermogravimetry to optimize sulfation roasting parameters such as time, temperature and quantity of sulfuric acid. Results show that copper can be selectively recovered as 99.9% of pure copper. Moreover, we recycled chemicals by-products of the plant in the process. Our findings suggest that this process is upscalable and should decrease the environmental pollution by Cu.