A Novel Green Technique to Recovery Valued Nonferrous-metal Compounds from Molten Slags

摘要

Based on several case studies in precipitating behavior of valued nonferrous-metal compounds (VNMC) in molten slags a green technology to recovery VNMC from molten slags was proposed, in which three steps are involved: (1) The selective enriching the dispersed VNMC into the designed mineral phase in molten slag; (2) The selective coarsening the designed mineral phase to critical grain size in molten slag; (3) The selective separating the grown mineral phase in solidified slag from tailing by dressing or hydrometallurgy processes. The features of the technique are clean, low-cost and a great capacity to deal with a large quantity of slags. The utilization of recovered VNMC such as titanium, boron, vanadium compounds was summarized as examples of technique's application. It was confirmed by experiments that the precipitating behavior of the designed mineral phases like perovskite (CaTiO3), suanite (2MgO. B2O3) and sincosite (CaO.V2O5. P2O5) in molten slags is obviously affected by operation factors such as temperature, chemical composition, heat-treatment, additives and so on. The precipitating kinetics and mechanism of VNMC from molten slags during solidification processes were also investigated.