Study On The Separation Of Binary Heavy Rare Earth Metal Ions Based On The Magnetic Moment Differences

As the scarce and non-renewable strategic resources in the world.Rare earth elements(La-Lu,Y&Sc)with excellent optical,electrical,magnetic,and hydrogen storage,such as catalytic performance in aviation,information,electronics,energy and other fields,were widely used.The current rare earth separation process is mainly based on the small difference in rare earth ion radius,with many extraction stages,large rare earth filling amounts,large acid and alkali consumption and other problems.Therefore,developing rare earth separation technology with high efficiency and low energy consumption is very important.The internal mechanism of rare earth separation is the intrinsic properties of rare earth.This study established the selective crystallization magnetic separation strategy of rare earth inorganic/organic ligands.A magnetic separation method for rare earth sulfate selective crystallization was designed.A selective crystallization magnetic separation method for rare earth sulfate was designed.The rare earth ionic liquid was designed and synthesized,and the selective crystallization magnetic separation process was optimized.The effects of radius and magnetic moment on the rare earth magnetic separation were investigated.To explore the internal mechanism of rare earth magnetic separation,a green and efficient rare earth separation strategy with low energy consumption and material consumption was proposed.The main research content and conclusions of this paper are as follows:(1)Based on the significant magnetic moment difference between rare earth elements,a new method for enhancing the selective crystallization and magnetic separation of rare earth sulfate using magnetic field at room temperature and pressure was proposed.An experimental proof of concept is provided for the binary systems RE2(SO4)3-Lu2(SO4)3(RE=Gd,Nd,Tb,Dy or Ho).This magnetic separation process increases the Gd(Ⅲ)-Lu(Ⅲ)separation factors from their mixture by 39%in kinetics but similar in or near thermodynamic equilibrium without magnetic field.The βRE/Lu(RE=Gd,Nd,Tb,Dy or Ho)were promoted by 17%-47%with magnetic field.The effects of magnetic field intensity and environmental temperature on rare earth magnetic separation were investigated.The magnetic field intensity increased from 0 T to 0.6 T,and the separation factors of Ho(Ⅲ)-Lu(Ⅲ)increased by 36%.The temperature decreased from 25℃ to 8℃,the Gd(Ⅲ)-Lu(Ⅲ)separation factors increases by 57.4%with magnetic field.(2)The effect of magnetic field on rare earth magnetic separation was further investigated.A series of rare earth ionic liquids were designed and synthesized.And the rare earth ionic liquids[C4py]4[RE(OTf)7]were screened.The separation factors of Gd(Ⅲ)-Lu(Ⅲ)system was increased by 16%with magnetic field.To investigate the effects of magnetic susceptibility and radius of rare earth ions on the separation factors.The βGd-RE(RE=La,Y,Lu,Sc)was increased by 13%-136%with the magnetic field.The Gd(Ⅲ)-Sc(Ⅲ)separation factors with magnetic field(0.6 T)was 52.7.Compared with the magnetic field intensity of 0.1 T,the separation factors was increased by 118%.(3)Basic research on rare earth separation based on magnetic moment difference.The magnetic source of rare earth inorganic/organic complex was analyzed.Gd2(SO4)3·8H2O is paramagnetic with magnetic field,while Lu2(SO4)3·8H2O is diamagnetism with/without magnetic field.The magnetic response mechanism of magnetic particles and rare earth ions was explored.The magnetic response mechanism achieves paramagnetic rare earth magnetic migration.The magnetic separation process of rare earth ions in solution was studied.The effect of synergistic crystallization on magnetic separation of rare earth was investigated.