| Abstract Scope |
Recycle of rare and precious metal (RPMs) solid wastes is significantly important for the sustainability of scarce resources and human society, but the extraction and concentration processes are still facing many challenges. To address this, we proposed the "silicon extraction and concentration" method since 2020, and have applied it to treat RPMs solid wastes such as Ti-bearing blast furnace slag, rare earths slags, spent SCR catalyst, and spent automotive catalyst through only two steps. In the first step, silicon was used as a getter to extract titanium, rare earths, tungsten, vanadium, and platinum group metals from RPMs solid wastes, and the extracted RPMs were found to be concentrated at the grain boundaries of silicon crystals; in the second step, electromagnetic directional crystallization technology was used to separate RPMs concentrates from Si matrix, and high-purity Si materials and RPMs concentrates were obtained simultaneously without discharging gas, water and harmless solid wastes. |