Study on Effective Extraction of Al and Fe from High-iron Bauxite Through "Calcification-Carbonization" Method

Abstract

With the rapid development of China alumina production, efficient utilization of plentiful low grade high-iron bauxite has received widespread attention in the aluminum industry. Based on this, "calcification-carbonization-direct reduction" method is proposed for extracting effectively valuable metals Al and Fe from high-iron bauxite. The research results indicate that: after the calcification-carbonization process for high-iron bauxite, leaching rate of Al2O3 can reach 83.67%, higher than extraction rate of Al2O3 through Bayer method. Then, direct reduction of calcification-carbonization residue is investigated. Metallization ratio of Fe is 80.5% when reduction temperature and time is 1050°C and 2h respectively. Moreover, metallization ratio of Fe can reach 93.6% with the addition of additive A. After the "calcification-carbonization-direct reduction" process, valuable metals Al and Fe can be extracted effectively from high-iron bauxite. The main component of final residue is CaCO3 and CaSiO3, which can be directly applicable to the cement industry.