Commercial and Technical Prospects of Unused Mineral Values of Aluminium Industry

In general, the overall requirement of aluminium metal is met by primary aluminium production involving the Bayer chemical process clubbed with Hall–the Héroult electrolytic process and secondary aluminium production based on the recycling of old and new scrap metal. The process of recycling undergoes remelting or refining to metal based on the type of scarp. Both primary and secondary production of aluminium is left with a variety of solid rejects which are useful materials for productive applications. These material rejects appear in the form of unprocessed solid materials of various kinds having differential chemical and mineralogical compositions containing aluminium, iron, and silica as major components such as mining rejects. Low-grade Bauxite (LB), Overburden Laterite (OBL), Kaolinitic Khondalite (KK), Partially Lateritic Khondalite (PLK), lithomargic clay known as Saprolite (SL), etc. are some of the major unprocessed resources suitable for commercial exploitation. Processed rejects of aluminium production mainly represent the Red Mud (RM), Aluminium Dross (AD), and Spent Pot-lining Materials (SPL). In the present paper, the potential of the processed and unprocessed reject as resources for preferred applications are discussed along with technical hints of value addition for commercial exploitation.