摘要
The effects of Ca-based additives on roasting properties of low-grade molybdenum concentrate were studied. The resultsshow that calcium-based additives can react with molybdenum concentrate to form CaSO4 and CaMoO4. The initial oxidationtemperature of MoS2 is 450℃, while the formation of CaMoO4 and CaSO4 occurs above 500℃. The whole calcification reactionsare nearly completed between 600 and 650℃. However, raising the temperature further helps for the formation of CaMoO4 but isdisadvantageous to sulfur fixing rate and molybdenum retention rate. Calcification efficiency of Ca-based additives follows theorder： Ca（OH）2〉CaO〉CaCO3. With increasing the dosage of Ca（OH）2, the molybdenum retention rate and sulfur-fixing rate rise, butexcessive dosages would consume more acid during leaching process. The appropriate mass ratio of Ca（OH）2 to molybdenumconcentrate is 1：1. When roasted at 650 ℃ for 90 min, the molybdenum retention rate and the sulfur-fixing rate of low-grademolybdenum concentrate reach 100% and 92.92%, respectively, and the dissolution rate of molybdenum achieves 99.12% withcalcines being leached by sulphuric acid.
研究了钙基添加剂对低品位钼精矿焙烧性能的影响.结果表明,钙基添加剂可与钼精矿反应生成CaSO4和CaMoO4.450 ℃ 时MoS2 开始氧化,500 ℃ 以上生成CaMoO4 和CaSO4,600-650℃ 时钙化反应基本完成;进一步提高焙烧温度有利于CaMoO4 的生成,但会降低焙烧过程固硫率和钼保留率.钙基添加剂焙烧效果依次为Ca（OH）2〉CaO〉CaCO3.随着Ca（OH）2 用量的增加,钼保留率和固硫率均呈上升趋势,但过多的钙基添加剂会使酸浸过程硫酸的消耗增加,Ca（OH）2 与钼精矿适宜的质量比为1：1.在650 ℃下焙烧90 min 时,低品位钼精矿钙化焙烧过程中钼保留率为100%、固硫率为92.92%,经硫酸浸出后钼的浸出率达到99.12%.
基金
Project(51304245)supported by the National Natural Science Foundation of China
Project(2014T70691)supported by the Postdoctoral Science Foundation of China
Project(2015CX005)supported by the Innovation Driven Plan of Central South University,China
Project supported by the Hunan Provincial Co-innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources,China
