Vacuum distillation refining of crude lithium （ II）——Kinetics on vacuum distillation of crude lithium
摘要
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 crude 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 1.492×10-1～8.244×10-1 g*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.