(1. 中南大学 资源加工与生物工程学院，长沙 410083；
2. 大冶有色金属集团控股有限公司，黄石 435100)
摘 要: 研究品位为39.27%的低品位钼精矿的氧化焙烧热力学、物相演变规律及焙烧特征。热力学分析表明：MoS2氧化的趋势仅次于FeS2氧化趋势，能生成多种价态的氧化物，且生成的MoO3可与多种金属氧化物反应生成钼酸盐，其中生成钼酸钙的趋势最大。焙烧过程包括MoS2氧化不充分、MoO3稳定存在和钼酸盐生成3个阶段，温度过高或时间过长易生成不利于后续钼溶出的钼酸盐和低价氧化钼，适宜的焙烧温度为650~675 ℃、焙烧时间为2 h左右。氧化焙烧后，氨浸的钼溶出率仅为84.02%，浸出渣中钼含量高达13.93%，XRD分析表明浸出渣的组成以钼酸钙为主。采用Na2CO3为浸出剂对氨浸渣进行二次浸出，可将氨浸渣中的钼酸钙溶出，最终钼的总回收率可达90.82%。
关键字: 低品位钼精矿；热力学；氧化焙烧；物相变化
（1. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China;
2. Daye Nonferrous Metals Group Co., Ltd., Huangshi 435100, China）
Abstract:Thermodynamics of oxidation roasting, phase evolution rules and roasting characteristics of low grade molybdenum concentrate with grade of 39.27% were studied. Thermodynamics analyses show that the oxidation tendency of MoS2 is second to that of FeS2, so it is easily oxidized and generates several oxide products. Furthermore, MoO3 could react with various metal oxides to generate molybdate in which calcium molybdate generates most easily. Roasting process contains three stages of incomplete oxidization of MoS2, stable existence of MoO3 and generation of molybdate. Molybdate and low valence molybdenum oxide, which go against subsequent leaching, will easily generate at over high temperature or for long time. The suitable temperature is 650-675 ℃ and the roasting time is 2 h. After roasting, ammonia leaching rate of molybdenum is only about 84.02%, residue of Mo in leaching residue reaches 13.93%. XRD analysis shows that calcium molybdate is the main component in leaching residue. When Na2CO3 is used as the leaching reagent, calcium molybdate can be extracted during leaching residue, and the ultimate recovery rate of Mo can reach 90.82%.
Key words: low grade molybdenum; thermodynamics; oxidation roasting; phase evolution
