Mixed solid waste from the decommissioning of coal-fired power plants as a resource of high value metals

Abstract The possibility of recovering metals from a mixture of solid industrial waste generated from decommissioning of a coal-fired power plant has been studied in this work. First, a complete characterization of the material was carried out. Results showed that the material contains an interesting amount of metals (Ti, V, Cr, Ni, Zn and Pb) that can be recovered by acid leaching and chemical precipitation. Then, some leaching tests were performed in batch systems with different acid solutions at different operational conditions. The main effects of leaching time, leaching agent and acidity were investigated. High concentrations of metal were achieved in the leachate obtained when a treatment with sulfuric acid solution at a pH value of 1 was used as leaching agent. Finally, the metals presented in leaching solution were precipitated by chemical precipitation with NaOH. A good separation of Ti and V respect to the other dissolved elements between pH 4 and 5 was obtained.