中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 36 No. 1 January 2026 |
（a Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, China;
b School of Metallurgy, Northeastern University, Shenyang 110819, China;
c Key Laboratory for Recycling of Nonferrous Metal Resources (Shenyang), Shenyang 110819, China）
Abstract:To synergistically recover alumina and alkali from red mud (RM), the structural stability and conversion mechanism of hydroandradite (HA) from hydrogarnet (HG) were investigated via the First-principles, XRF, XRD, PSD and SEM methods, and a novel hydrothermal process based on the conversion principle was finally proposed. The crystal structure simulation shows that the HA with varied silicon saturation coefficients is more stable than HG, and the HA with a high iron substitution coefficient is more difficult to be converted from HG. The (110) plane of Fe2O3 is easier to combine with HG to form HA, and the binding energy is 81.93 kJ/mol. The effects of raw material ratio, solution concentration and hydrothermal parameters on the conversion from HG to HA were revealed, and the optimal conditions for the alumina recovery were obtained. The recovery efficiencies of alumina and Na2O from the RM are 63.06% and 97.34%, respectively, and the Na2O content in the treated RM is only 0.13%.
Key words: hydrogarnet; hydroandradite; structural stability; hydrothermal conversion; red mud
