熔盐电解钕中金属的溶解和泥渣的形成探讨

Solution of Neodymium and Formation of Slime during the Neodymium Electrolysis

采用金属质量差法,对金属钕在NdF3与LiF质量比为10∶1.2的NdF3-LiF电解质中的溶解度进行测定,分析了金属钕在电解质中溶解损失随温度的变化情况,使用X射线衍射分析法测定了溶解度实验后的金属外层包裹物以及钕电解槽中泥渣中的物相,对泥渣的成因和如何提高电流效率进行了探讨。结果表明,钕的溶解度随温度升高而增大,金属溶解后生成NdOF和NdF2,溶解产物参与了渣泥的生成;通过降低电解温度到1040±10℃,并以95 g.min-1的加料速度控制好加料,可以提高电流效率。

In this article, mass difference method used to determine dissolvability of neodymium in NdF3-LiF electrolyte, in which the content of neodymium fluoride was about 89.3 % （mass fraction） （ that is, NdF3：LiF = 10：1.2 in mass ratio）. The phases in neodymium-cladding and slime were examined using XRD method after the determination of dissolvability. And the reason of forming the slime and a way to improve current efficiency of the electrolytic process were discussed also. Experimental results indicated that dissolvability of neodymium in molten NdF3-LiF rapidly increased with a rise in temperature. The XRD results showed that in molten salt dissolved metal Nd formed NdOF and NdF2 which exited in neodymiumcladding and took part in forming slime and Nd203 phase was in the slime. It is the same as slag by the large, but Nd2O3 phase within slag. Experiments showed that decreasing the temperature to 1040 ± 10 ℃ and controlling the feed rate at 95 g· min^-1 would improve the current efficiency.