Vacuum distillation refining of
crude lithium (Ⅱ)──Kinetics on vacuum distillation of crude lithium
crude lithium (Ⅱ)──Kinetics on vacuum distillation of crude lithium
(1.Department of Metallurgical Science & Engineering,
Central South University, Changsha 410083,China；
2.Research Institute of Vacuum Metallurgy & Material,
Kunming University of Science and Technology,Kunming 650093,China)
Central South University, Changsha 410083,China；
2.Research Institute of Vacuum Metallurgy & Material,
Kunming University of Science and Technology,Kunming 650093,China)
Abstract: Kinetics on vacuum refining process of crude lithium was studied by using maximum evaporation rate,critical pressure and mean free path of elements in the crud e lithium at different temperatures. Behaviors of impurities in the vacuum distillation process have been examined in detail.The results show that fractional vacuum distillation should be taken to obtain lithium with high purity; if the mass loss amount of lithium is 3%～5%, metal K, Na, Mg and Ca can be eliminated at lower temperature of 673～873K at pressure of less than 1.30Pa;the maximum rate of lithium distillation reaches 1.492×10-1～8.2 44×10-1g·cm-2·min-1 at higher temperature of 973～1073K at the pressure of 3.0～3.2Pa, which ensure complete separation of lithium from Al,Si,Fe and Ni.
Key words: lithium;refining;vacuum distillation;kinetics