Leaching of Ca-Rich Slags Produced from Reductive Smelting of Bauxite Residue with Na2CO3 Solutions for Alumina Extraction: Lab and Pilot Scale Experiments

Sustainable utilization of Bauxite Residue (BR) is currently one the greatest challenges being tackled by alumina industry, due to its high production rates and limited reuse options. The present work concerned with use BR as a candidate metallurgical raw material for iron (Fe) aluminum (Al) extraction. In more detail, at first, undergoes reductive smelting extract Fe content produce slag mainly calcium aluminate composition. second step, Al contained in phases extracted hydrometallurgically leaching Na2CO3 aqueous solution. focus current study optimization this process, it was performed two stages. first laboratory scale investigation on main parameters affecting extraction rate Al. stage pilot incorporated observations suggestions based investigation. Laboratory showed that than 50% could be easily less 1 h, 5% S/L, 70 °C an 20% excess Na2CO3. Pilot work, successfully applying derived from achieved average 68% 10% S/L pulp, optimized composition relation used scale.