对锂热还原-真空蒸馏联合法制备金属镧所涉及热力学和动力学因素进行了简要的分析,证明该工艺过程可行;在此基础上,在氩气气氛下考察了还原温度、还原剂用量和保温时间对金属收率的影响,确定了适宜的工艺条件为:还原反应温度为950℃,锂还原剂过量10%,反应保温时间1 h,在此工艺条件下金属镧收率可以达到95%以上。为降低氯化物吸水及气体杂质对金属镧的污染,将锂热还原和真空蒸馏除杂整合在同一设备中一次完成,制备得到了国内报道的目前高纯度的金属镧,绝对纯度为99.974%(相对于38个分析元素),相对纯度为La/REM≥99.995%,其中稀土金属杂质总量为42.7μg.g-1,非稀土金属杂质总量为100.1μg.g-1,气体杂质C,S,O,N分别为20,20,56和20μg.g-1。 The thermodynamic and kinetic factors involved in the preparation of metallic lanthanum by lithium-thermal reduction-vacuum distillation were briefly analyzed to prove the feasibility of the process. Based on this, the effects of the reduction temperature, the amount of reducing agent and The effect of holding time on the yield of metal was studied. The suitable process conditions were as follows: the reduction temperature was 950 ℃, the excess of lithium reductant was 10%, the reaction holding time was 1 h, the yield of lanthanum metal could reach 95% the above. In order to reduce the chloride absorption and gaseous impurities on metal lanthanum pollution, lithium thermal reduction and vacuum distillation and impurity removal in one device completed in the same preparation, prepared the current reported high purity lanthanum, the absolute purity of 99.974% ( Relative to 38 analytical elements), the relative purity is La / REM ≧ 99.995%, wherein the total amount of rare earth metal impurities is 42.7 μg.g-1, the total amount of non-rare earth metal impurities is 100.1 μg.g-1, the impurity impurities C, S, O, N were 20, 20, 56 and 20 μg.g-1, respectively.