(1. 中南大学资源加工与生物工程学院，长沙410083；
2. 大冶有色金属集团控股有限公司，黄石435100)
摘 要: 采用湿法浸出法提取低钼焙砂中的钼元素。采用XRD分析低钼精矿氧化焙烧所得钼焙砂的物相组成，发现钼焙砂中因存在钼酸盐及低价钼，导致氨浸的钼浸出率低。采用含HNO3/NH4NO3预处理的方法研究了低品位钼焙砂的强化提钼。结果表明：HNO3/NH4NO3预处理使难溶钼酸盐转化为可溶于氨水的钼酸，同时，在酸盐效应的作用下抑制预处理过程钼的损失，从而提高钼的综合回收率。HNO3/NH4NO3预处理的适宜工艺参数：HNO3浓度120 g/L、NH4NO3浓度100 g/L、液固比3:1、浸出时间120 min、浸出温度90 ℃。与非预处理的直接氨浸相比，氨浸渣中残留的钼含量从20.00%降低到5.13%，钼的回收率从75.90%提高到95.38%。
关键字: 低品位钼精矿；钼焙砂；难溶钼酸盐；预处理；氨浸
（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:Molybdenum was extracted by hydrometallurgy leaching from low grade molybdenum calcine. The mineral compositions of the calcine roasted from low grade molybdenum concentrate were tested by X-ray diffraction. The results indicate that the leaching rate by ammonia is low because of the existence of molybdate and low state of molybdenum phase in the molybdenum calcine. The strengthening leaching for low grade molybdenum calcine by HNO3/NH4NO3 pretreatment was investigated. The results show that the undissolved molybdate is translated into dissolved molybdate in ammonia leaching by the HNO3/NH4NO3 pretreatment. Meanwhile, the loss of molybdenum is restrained with the effect of acid and salt. Thus, the comprehensive recovery rate of molybdenum is improved. The operating parameters of optimum process is established as follows: HNO3 concentration is 120 g/L, NH4NO3 concentration 100 g/L, liquid-solid ratio 3:1, pretreating time 120 min, reaction temperature 90 ℃. Compared with the direct ammonia leaching without pretreatment, the molybdenum content in the ammonia leaching residue reduces from 20.00% to 5.13%, and the comprehensive recovery rate of molybdenum increases from 75.90% to 95.38% with the processing of pretreating-ammonia leaching.
Key words: low grade molybdenum concentrate; molybdenum calcine; undissolved molybdate; pretreatment; ammonia leaching
