Pyrometallurgical recovery of gallium from GaN semiconductor through chlorination process utilizing ammonium chloride

Abstract

Pyrometallurgical chlorination process has been examined for the recovery of gallium from gallium nitride, GaN, a promising semiconductor material. It was found that gallium was successfully recovered as volatile gallium chloride by thermal treatment of GaN powder in the presence of ammonium chloride. All gallium could be recovered as volatile species at 500°C. The results indicate that gallium can be extracted from complex mixture of semiconductor materials or wastes through this process. The influence of reaction conditions, such as reaction temperature and composition of ammonium chloride, was examined.