Calcification Roasting Acid Leaching and Kinetics of Rare Earth Molten Salt Slag
Aiming at the problem of low efficiency of rare earth recovery from rare earth molten salt electrolysis slag,CaO roasting transformation-hydrochloric acid leaching method is proposed.This method systematically in-vestigated the effects of calcination temperature,calcination time,CaO addition,hydrochloric acid concentra-tion,leaching time,liquid-solid ratio,and leaching temperature on the extraction effect of rare earth in slag,and the kinetic calculation of the calcination process was carried out.The results show that under the conditions of roasting temperature 700 ℃,roasting time 3 h,mass ratio of CaO to rare earth molten salt electrolysis slag 0.9∶1,hydrochloric acid concentration 5 mol·L-1,leaching time 1.5 h,liquid-solid ratio 15∶1,leaching temper-ature 50 ℃ and leaching time 1.5 h,the rare earth leaching rate reaches 99.03％.The roasting process is con-trolled by chemical reaction.Activation energy of this process is 65.46 kJ·mol-1 and the kinetic equation is 1-(1-x)1/3=exp(5.31068-7874.03289/T).
rare earthmolten salt electrolysis slagcalcium oxide roastinghydrochloric acid leachingapparent activation energy
NETL
NSTL
万方数据
