Alumina & Bauxite: Bauxite Residues Technology
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Zhang Ting'an, Northeastern University
Tuesday 8:30 AM
February 28, 2017
Location: San Diego Convention Ctr
Session Chair: Guanghui Li, Central South University
8:30 AM Introductory Comments
Security Disposal and Comprehensive Utilization of Bauxite Residues: Songqing Gu1; Zhonglin Yin1; Lijuan Qi1; 1Chalco
Security disposal and comprehensive utilization of bauxite residues are of great significance to the world alumina industry due to environmental protection requirement and waste materials recovery. The security disposal and utilization technologies for bauxite residue will be shown and discussed in this paper. The dry stacking technology for Bayer residues by the drum or pressure filters has been applied widely in the Chinese refineries from 10 years ago. Magnetic separation dressing of high iron content red mud for iron ore concentrates has been put into industrial operations in China for more than 5 years. The residue from sintering process is able to be used for red mud pool dam construction and Soil Modifiers for high acidic soil areas for neutralizing and adsorbing the harmful heavy metal compounds in the soil. The high caustic Bayer residues could be applied for such construction materials as foamed ceramics and glass ceramics etc. The further utilization possibilities and potentials in the future are outlined in the steelmaking, construction, agriculture and environmental industry etc.
Application of Tricalcium Aluminate Instead of Lime for the Recovery of Aluminum in Middle-low Grade Bauxite in Calcification-Carbonization Process: Yanxiu Wang1; Zhang Ting'an1; Guozhi Lv1; Xiaofeng Zhu1; Weiguang Zhang1; Liqun Xie1; 1Northeastern University
In the process of calcification-carbonization, the alkali and aluminum in the mid-low grade bauxite and red mud can be regained effectively. Aluminum is obtained in the form of low-concentration sodium aluminate solution which is comparatively difficult to reuse. In this paper, the low-concentration sodium aluminate solution was reused to prepare tricalcium aluminate and went back to the calcification-carbonization process instead of lime. When processing gibbsite and diasporic bauxite with calcification-carbonization method, the effect of calcium aluminate on dealkalization and dealumination was investigated. The results show that the alumina-silica ratio of these two ores can be reduced to 0.70, and the sodium alkali content can be reduce to less than 0.50%. It indicates that it’s feasible to use calcium aluminate replacing lime. The proposal well solved the problem that aluminum is difficult to recycle at low concentrations and enhances the effectiveness and cleanness of calcification-carbonization process which has an extensive prospect.