(1. 中南大學(xué) 資源加工與生物工程學(xué)院，長沙 410083；
2. 大冶有色金屬集團(tuán)控股有限公司，黃石 435100)
摘 要: 研究品位為39.27%的低品位鉬精礦的氧化焙燒熱力學(xué)、物相演變規(guī)律及焙燒特征。熱力學(xué)分析表明：MoS2氧化的趨勢僅次于FeS2氧化趨勢，能生成多種價態(tài)的氧化物，且生成的MoO3可與多種金屬氧化物反應(yīng)生成鉬酸鹽，其中生成鉬酸鈣的趨勢最大。焙燒過程包括MoS2氧化不充分、MoO3穩(wěn)定存在和鉬酸鹽生成3個階段，溫度過高或時間過長易生成不利于后續(xù)鉬溶出的鉬酸鹽和低價氧化鉬，適宜的焙燒溫度為650~675 ℃、焙燒時間為2 h左右。氧化焙燒后，氨浸的鉬溶出率僅為84.02%，浸出渣中鉬含量高達(dá)13.93%，XRD分析表明浸出渣的組成以鉬酸鈣為主。采用Na2CO3為浸出劑對氨浸渣進(jìn)行二次浸出，可將氨浸渣中的鉬酸鈣溶出，最終鉬的總回收率可達(dá)90.82%。
關(guān)鍵字: 低品位鉬精礦；熱力學(xué)；氧化焙燒；物相變化
（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
