The global PV industry has rapidly developed over the past decade, which has led to a large demand for silicon materials. Solar cells are currently fabricated from a variety of silicon‐based materials. However, current market is difficult to ensure a steady supply for this material. Development of a new process to produce silicon at low cost is definitely necessary. Metallurgical grade silicon (MG‐Si) with the purity of 98%, which is produced by carbothermic reduction in electric arc furnaces, has been considered as a cheap starting material for conversion to purity of 99.99%. Many alternative methods for purifying MG‐Si to Solar grade silicon (SoG‐Si) have been explored, for example, (1) pyro metallurgical processes, (2) hydrometallurgical processes and (3) electrochemical methods. Metallurgical route is recognized as a promising process to meet market demand for solar energy silicon material, which is different from the traditional Siemens process. This chapter focuses on the introduction of three kinds of typical impurity removal methods in metallurgical process, and the impurity removal effect of different processes was analysed and discussed.
Part of the book: New Research on Silicon