Study On The Process Of Separating Rare Earth And Aluminum By Organophosphorus Ligand Complexation

The physical and chemical properties of rare earth elements are special,and high-purity single rare earths are necessary in today’s society.China’s rare earth reserves,varieties,quality,output and export are the first in the world,it has a global influence on rare earth related research.The weathering crust leaching type rare earth ore,which was first discovered in south and coveted by western countries for a long time,has been the focus and difficulty of research on the removal of impurity aluminum because of its ore phase structure and leaching process.Researchers have done a lot of research and developed a large number of aluminum removal processes,but there are still some defects.In this paper,based on extensive literature research and previous research of the research group,the separation of rare earth and impurity aluminum in simulated rare earth solution was studied by using phosphorus-containing organic ligands.The process of complex separation of rare earth and aluminum elements by DOPO,the process of complex separation of rare earth and aluminum elements by CEPPA and the process of complex separation of rare earth and aluminum elements by REG are proposed respectively.（1）Study on the process of complex separation of rare earth and aluminum elements by DOPO.Use the difference of ion selectivity of DOPO in the simulated rare earth solution to carry out complex study,investigate the p H value,DOPO dosage,reaction time,reaction temperature and ion concentration in solution on the complex separation of rare earth and aluminum elements by DOPO.The experimental results show that when the p H value of the simulated feed solution is 1,the DOPO dosage is M_DOPO:M_RE³⁺=6:1 equivalent,the reaction time is 10 min and the reaction temperature is 30℃,the precipitation rate of rare earth is 80.95%and that of aluminum is 25.60%.Under the condition that the amount of DOPO is constant,the change of aluminum ion concentration in the feed solution has no effect on the precipitation rate of rare earths,and the higher the concentration of aluminum ion is,the lower the precipitation rate of aluminum is.（2）Study on the process of complex separation of rare earth and aluminum elements by CEPPA.Use the difference of ion selectivity of CEPPA in the simulated rare earth solution to carry out complex study,investigate the p H value,CEPPA dosage,reaction time,reaction temperature and ion concentration in solution on the complex separation of rare earth and aluminum by CEPPA,and the reaction path was simulated by gaussian software.The experimental results show that when the p H value of the simulated feed solution is 1,the CEPPA dosages is M_CEPPA:M_RE³⁺=6:1 equivalent,the reaction time is 10 min and the reaction temperature is 50℃,the precipitation rate of rare earth ions is 90.48%and the precipitation rate of aluminum ions is 9.52%.Under the condition that the amount of CEPPA is constant,the concentration of aluminum ions in the feed solution has no effect on the precipitation rate of rare earths.The higher the concentration of aluminum ions is,the lower the precipitation rate of aluminum is.（3）Study on the process of complex separation rare earth and aluminum elements by REG.Use the difference of ion selectivity of REG in the simulated rare earth solution to carry out complex study,investigate the p H value,REG dosage,reaction time,reaction temperature and ion concentration in solution on the complex separation of rare earth and aluminum by REG.The experimental results show that when the p H value of the simulated feed solution is 2.5,the REG dosages is M_{REG monoer}:M_RE³⁺=12:1 equivalent,the reaction time is 10 min and the reaction temperature is 50℃,the precipitation rate of rare earth is 91.35%and that of aluminum is 11.22%.The process of separating rare earths and aluminum elements by REG precipitation is different from the former two materials.When the concentration of aluminum ions in the feed solution increases,the precipitation rate of rare earths decreases,and with the increase of the concentration of aluminum ions in the feed solution,the total amount of precipitation of aluminum ions will also increase.