Extraction of REEs (Ce, Tb, Y, Eu) from Phosphors Waste by a Combined Alkali Roasting–Acid Leaching Process

Rare Earth (RE) phosphors waste contains valuable rare elements (REEs), such as cerium, terbium, yttrium, and europium. In industry, the process of NaOH roasting followed by acid leaching is usually used to extract REEs from in China. Using this process, efficiencies cerium terbium are clearly lower than those other REEs, which results uneven extraction low total REE efficiency. The key reason that trivalent oxidized into RE oxides during roasting, difficult dissolve solution. To solve problem, an optimized controlling oxygen concentration proposed paper. influences concentration, temperature, time, mass ratio phosphor NaOH, HCl solution liquid–solid on efficiency were investigated. Under optimum conditions, increased dramatically 99.11%.