The extraction of manganese from low-grade manganese oxide ores using CaS derived from CaSO 4 as reductant was investigated. The effects of mass ratio of CaS to ore, reduction temperature, reduction time, liquid to solid ratio (L/S ratio), stirring speed, leaching temperature, leaching time and H 2 SO 4 concentration on the leaching rates of Mn and Fe during the reduction–acid leaching process were discussed. The leaching rates of 96.47% for Mn and 19.24% for Fe were obtained under the optimized conditions of mass ratio of CaS to manganese oxide ore 1:6.7, L/S ratio 5:1, stirring speed 300 r/min, reduction temperature of 95 °C for 2.0 h in the reduction process and leaching stirring speed of 200 r/min, H 2 SO 4 concentration of 1.5 mol/L, leaching temperature of 80 °C for 5 min in the leaching process. In addition, this process can be employed in the recovery of manganese from various manganese oxide ores, and Mn leaching rate above 95% is obtained.
Lu Yao,Guangzhi Xin,Pengyan Pu,Lin Yang,Xia Jiang,Zhicheng Jiang,Wenju Jiang
In this work, Mn ore was mixed with the wastewater anode solution of electrolytic Mn (ASEM, instead of water) and utilized as the desulfurizer for simultaneous SO 2 removal from flue gas and Mn extraction. The effects of Fe 2+ and Fe 3+ on Mn leaching and flue gas desulfurization were investigated. For MnO 2 and Mn 2 O 3 (mixed with ASEM), the introduction of Fe 2+ could simultaneously increase Mn extraction efficiency and flue gas desulfurization efficiency when MnO 2 and Mn 2 O 3 mixed with ASEM was used. Fe 3+ addition could improve desulfurization efficiency obviously for MnCO 3 . Fe 2+ could react with MnO 2 and H + to form Mn 2+ and Fe 3+ . This reaction further improved Mn extraction and simultaneously decreased the acidity of ASEM, thus promoting SO 2 removal. The introduced Fe 3+ could react with SO 2 , when MnO 2 was absent from the desulfurizer slurry. The resulting Fe 2+ was then oxidized by O 2 to form Fe 3+ , which underwent a Fe 3+ ↔ Fe 2+ cycle to promote flue gas desulfurization. Thus, the introduction of Fe ions, especially Fe 2+ , could promote simultaneous Mn leaching and flue gas desulfurization with Mn ore. This work provided not only a new way for effective SO 2 removal from flue gas and Mn extraction but also for recycling ASEM.
危险品化学品经营许可证（带存储）