钙热还原法制备高纯金属镧的研究

Preparation of High-purity Lanthanum by Calciothermic Reduction

进行了钙热还原法制备高纯金属镧的工艺研究。研究了氟化过程中坩埚材质的影响,选择金属镍舟做氟化坩埚;考察了高纯氩气保护下还原反应温度、保温时间以及还原剂量与金属收率的关系,确定了适宜的工艺参数为:还原温度1 600℃,金属钙过量10%,保温20 min,在此条件下金属收率达到95%以上,制备得到纯度达99.948%(质量分数,相对于38个分析元素)的高纯金属镧。本工艺设备简单,环境要求低,适合工业生产高纯金属镧。

Research was conducted on the preparation of high-purity lanthanum by calciothermic reduction. Based on the study of the influence of crucible materials on fluorination process, Ni was chosen as the material for crucible. After the investigation of relationship between metal yield with reduction temperature, soaking time as well as dosage of reducing agent, a proper process condition was determined as follows ： reduction at a temperature of 1 600℃ for 20 min, with 10% more reducing agent resulted in a lanthanum product with purity up to 99. 948% with yield exceeding 95%. This method is suitable for industrial manufacturing of high purity lanthanum due to simple equipment and low requirement for environment in this technology.