(1. 中南大學資源加工與生物工程學院，長沙410083；
2. 大冶有色金屬集團控股有限公司，黃石435100)
摘 要: 采用XRD和TG-DSC分析研究低品位鉬精礦石灰氧化焙燒過程的反應(yīng)機理，確定石灰法焙燒-酸浸提鉬工藝的優(yōu)化參數(shù)。熱重分析表明：石灰法焙燒主要發(fā)生Ca(OH)2的分解、MoS2的氧化、MoO2的再氧化及鉬酸鹽的生成等反應(yīng)，焙燒過程主要產(chǎn)生MoO2、MoO3、CaMoO4、CaSO4等物相。XRD分析表明：當溫度高于600℃、反應(yīng)時間大于90min時，焙砂中低價態(tài)鉬的衍射峰完全消失，此時焙砂主要物相為CaMoO4和CaSO4，輝鉬礦被充分氧化；石灰焙燒適宜的條件為Ca(OH)2與鉬精礦質(zhì)量比1:1、焙燒溫度650℃、焙燒時間90min，焙燒過程硫的保留率可達91.49%。鉬焙砂酸浸適宜的浸出溫度為90℃、浸出時間為2h、H2SO4濃度為70g/L、液固比為5:1，此時鉬浸出率可達99.12%，CaMoO4被完全溶出。
關(guān)鍵字: 低品位鉬精礦；石灰焙燒；酸浸；物相變化
（1. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China;
2. Daye Non-Ferrous Metals Group Holdings Co., Ltd., Huangshi 435100, China）
Abstract:The mechanism of chemical reactions was studied on the oxidation of low grade molybdenum concentrate with addition of calcium oxide by the methods of XRD and TG-DSC, andthe optimum conditions of calcium-based roasting and acid leaching were determined. The result of TG-DSC shows that the reactions are composed mainly of decomposition of Ca(OH)2, oxidization of MoS2, re-oxidization of MoO2 and the formation of molybdate. The products are MoO2, MoO3, CaMoO4 and CaSO4 in the process of oxidation roasting. The XRD result shows that the diffractions of low valence state molybdenum can not disappear completely until roasting temperature exceeds 600℃ and roasting time is longer than 90min. The main phases are CaMoO4 and CaSO4 in molybdenum calcine, and the molybdenite can be oxidized completely.The retaining ratio of sulfur can reach 91.49% under the conditions of mass ratio of Ca(OH)2 to molybdenum concentrate 1:1, roasting temperature 650℃ and roasting time 90min. The test shows that the leaching rate of molybedenum can reach 99.12% under the suitable conditions of leaching temperature 90℃, leaching time 2h, sulfuric acid 70g/L, the ratio of liquid to solid 5:1.
Key words: low grade molybdenum concentrate; calcium-based roasting; acid leaching; phase transformation
