Recoveries of rare elements Ga, Ge, In and Sn from waste electric and electronic equipment through secondary copper smelting

The results show that tin and indium can be efficiently recovered into the copper phase in reducing process conditions (pO2 below 10−7 atm), whereas gallium dissolved preferentially into the solid spinel phase in all conditions examined. Gallium dissolution into slag and spinel was found to occur as GaO1.5, whereas indium in spinel was determined to be as InO1.5. In addition, germanium was seen to distribute preferentially into the copper phase with LCu/s[Ge] = 2-4, although its concentrations in all phases present were relatively low. Thus, the main route for germanium can be considered to be vaporization.