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Fe S2氧化趋势,能生成多种价态的氧化物,且生成的Mo O3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、Mo O3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%。
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 MoS 2 is second to that of FeS 2 , so it is easily oxidized and generates several oxide products. Furthermore, MoO 3 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 MoS 2 , stable existence of MoO 3 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%.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2014年第12期3115-3122,共8页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(51304245
51174253)
中国博士后科学一等资助基金项目(2013M540639)
中国有色矿业集团总公司科技项目(2013KJJH06)
关键词
低品位钼精矿
热力学
氧化焙烧
物相变化
low grade molybdenum
thermodynamics
oxidation roasting
phase evolution
