低品位钼精矿的钼提取研究

采用焙烧—氨浸—渣碱浸工艺对某低品位钼精矿进行钼提取的研究.结果表明,碳酸钠的加入能有效分解钼酸钙,提高钼的提取率.焙烧—氨浸阶段最优工艺条件为焙烧温度600℃,焙烧时间2 h,氨浸温度80℃,氨水过量系数1.4,碳酸钠用量467 kg/t,液固比4.浸出渣中的钼分别采用酸法(HCl)和碱法(Na2CO3+NaOH)进行提取.结果表明:酸法仅可回收渣中34.92%的钼,而且操作过程不易控制,不适合实际应用;碱法(Na2CO3+NaOH)处理工艺中碳酸钠用量533 kg/t,氢氧化钠用量433 kg/t.放大实验结果显示整个流程钼的回收率达到96.8%.

Extraction of Molybdenum from Low-Grade Molybdenum Concentrates

Using roasting,ammonia leaching and alkaline leaching,the extraction of molybdenum from low-grade molybdenum concentrates was studied.The experimental results showed that the addition of the sodium carbonate increases the leaching rate of molybdenum by accelerating the decomposition of calcium molybdate.The optimum conditions for the molybdenum extraction are as follows: the roasting temperature is 600 ℃,the roasting time 2 h,the ammonia leaching temperature 80 ℃, the excess coefficient of aqueous ammonia 1.4,the dosage of the sodium carbonate 467 kg/t and the ratio of liquid to solid 4∶1.The leaching residue was treated by hydrochloric acid leaching(HCl) method and alkaline leaching(Na2CO3+NaOH) method separately to further leach molybdenum.The recovery rate of molybdenum in the residue is only 34.92% by the former method and,meanwhile,the leaching process by this method is difficult to control,showing that the method is not practicable.In the latter method,the dosages of the sodium carbonate and sodium hydroxide are 533 and 433 kg/t,respectively.The scale-up experiment showed that the total recovery rate of molybdenum is up to 96.8%.