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石灰焙烧-硫酸浸出法可大大降低传统氧化焙烧-氨浸工艺处理辉钼矿的含硫烟气污染,但存在设备腐蚀严重、渣量大等缺点。基于石灰焙烧工艺研究,本文作者提出“碳酸钙氧化焙烧-碳酸铵浸出”新工艺来处理辉钼矿。通过热力学计算、热重分析以及焙烧试验等对辉钼矿-碳酸钙氧化焙烧过程进行详细研究。结果表明,MoS_2与CaCO_3和O_2在573~1000K下反应的主要产物是CaSO_4、CaMoO_4和CO_2;当CaCO_3和MoS_2的摩尔比为3.6并加入5%矿化剂A在500°C下焙烧1h时,钼精矿中的MoS_2的分解率达到约99%,固硫率达到约95%。用碳酸铵溶液浸出焙烧后熟料,控制碳酸铵浓度为600g/L、液固比为10mL/g,在85°C下浸出7h,Mo浸出率可达98.2%。该研究结果将有助于钼酸铵清洁生产新技术的开发。
Lime roasting - sulfuric acid leaching method can greatly reduce the traditional oxidation roasting - ammonia leaching molybdenum sulfide flue gas pollution, but there are serious corrosion equipment, slag and other shortcomings. Based on the research of lime roasting process, the author proposed “new process of calcium carbonate roasting-ammonium carbonate leaching” to treat molybdenite. Thermodynamic analysis, thermogravimetric analysis and roasting test were used to investigate the oxidation roasting process of molybdenite-calcium carbonate. The results showed that the main products of reaction of MoS_2 with CaCO_3 and O_2 at 573 ~ 1000K were CaSO_4, CaMoO_4 and CO_2. When the molar ratio of CaCO_3 and MoS_2 was 3.6 and 5% mineralizer A was added, calcined at 500 ° C for 1h, The decomposition rate of MoS_2 in molybdenum concentrate reaches about 99% and the sulfur fixation rate reaches about 95%. The roasted clinker was leached with ammonium carbonate solution to control the concentration of ammonium carbonate to 600g / L, the liquid-solid ratio of 10mL / g and the leaching time of 7 h at 85 ° C. The leaching rate of Mo reached 98.2%. The findings will help the development of new technologies for the clean production of ammonium molybdate.