中文摘要：

钼是重要的战略金属。目前随着钼需求的增加和钼矿资源的不断开采,我国钼矿资源日益紧缺,低品位钼矿将成为重点开采对象,其经济开发和合理利用工艺也将成为研究热点。本文针对我国钼矿品位低、脉石含量高的特点,采用碳酸钠低温焙烧,焙烧过程生成的钼酸盐经水浸出进入溶液,实现与脉石矿物的分离。由焙烧过程的热力学分析可知,焙烧温度在523-873 K范围内,钼酸盐的生成吉布斯自由能小于0,且生成趋势随着温度的升高而逐渐减小,二氧化硅和氧化铝的反应活性较低。研究了焙烧过程中矿粉粒度、焙烧温度、焙烧时间和碱矿比对钼转化的影响和杂质硅引入的控制方法。通过矿样、熟料和浸出渣的X射线衍射（XRD）分析,研究了钼的转化历程。结果表明：当矿粉粒度为80-96μm,焙烧温度为550℃,焙烧时间为3 h,碱矿比为2∶1时,钼的转化率可达到93.9%,硅的转化率小于1.3%。为低品位钼矿的开发和利用提供理论指导和技术参考。

英文摘要：

Molybdenum is an important strategic metal. Currently, molybdenum ore resources in China are becoming shortage in- creasingly as the continuous exploitation of mines and the increasing demand for molybdenum. Therefore, low-grade molybdenum will become the key object of exploitation, and the economic development and reasonable utilization of it will become the focus of research. According to the characteristics and the properties of low-grade molybdenum ore, such as low grade and high gangue content, the process of low-temperature roasting by sodium carbonate was used, and the molybdate generated during roasting could dissolve into water by leaching method, realizing the separation from gangue minerals. The results of thermodynamic analysis showed that when the temperature was in the range of 523 - 873 K, the Gibbs free energy of molybdate formation was less than 0, and the formation trend detracted with the temperature increasing gradually. In addition, the reaction activity of silica and alumina was very low. The effects and regulation of powder panicle size, roasting temperature, roasting time and the mass ratio of alkali to ore on the conversion of molybdenum and the control of impurity silicon introduction were investigated. Through X-ray diffraction （XRD） analysis of ore samples, clinker and leaching residue, the transformation process of molybdenum were studied. The results showed that under the roasting conditions of ore particle size of 80 - 96 μm, roasting temperature of 550 ~C, roasting time of 3 h and the alkali/ore mass ratio of 2, the conversion rates of molybdenum and silicon reached 93.9% and less than 1.3% , respectively. It would provide theoretical guidance and technical reference for the development and the utilization of low-grade molybdenum ore.