Research On Uranium In Wastewater Incorporated Into Magnetite With Micro Current Induction And The Separation Of Iron And Uranium

To incorporated uranium into the artificial ore lattice is a new idea,which decrease the risk of uranium migration and pollution through high-efficiency mineralization.Re-release of uranium from the crystal lattice of artificial ore and recycling it as a resource can finally eliminate the persistent uranium pollution in nature and is expected to alleviate the shortage of uranium resources.However,the formation conditions of the artificial ore are complex,and it has strong stability because of its long-range orderly crystal structure,making uranium resources recovery become a difficult challenge without destroying the ore structure,which limits practical application of mineralization in the treatment of uranium-containing wastewater.In view of this,this study took 10 mg/L uranium-containing wastewater as the research object,and innovatively designed an electrochemical mineralization system to realize the mineralization of uranium in the wastewater,and then through roasting conversion-weak acid leaching to achieve iron re-separation of uranium.The effects of electrochemical process parameters and solution water quality parameters on uranium removal rate and the transformation characteristics of photochemical properties of uranium-containing magnetite during roasting were investigated,and the separation mechanism of iron and uranium was determined.The main conclusions of the study are as follows:(1)The research results of incorporating uranium to magnetite through micro-current induction show that the uranium removal rate can basically reach equilibrium in about 40 minutes,and the maximum uranium removal rate can reach more than 90%.Increasing the initial concentration of uranium in the solution can increase the uranium removal rate.Impurity ions such as K+,Ca2+,Fe3+ have no significant effect on the uranium removal.XRD results show that the main composition of uranium-doped magnetite is Fe3O4,and the doping of uranium does not change the inverse spinal structure of magnetite.XPS results show that uranium exists in a small amount of U(?)and forms in magnetite,and most of the uranium enters into the Fe3O4 crystal lattice to be incorporated in the form of U(?).SEM and TEM results show that the uranium-doped magnetite is cohesive spherical particles,showing a cauliflower-like morphology,and the particle size is 20-100 nm.(2)The results of oxidation roasting of uranium-bearing magnetite show that,it is found that uranium-bearing magnetite can be further transformed into hematite with corundum structure and U3O8 can be precipitated at the temperature above 700 ? by in-situ high temperature XRD.HRTEM and DFT calculations show that Fe3O4 is gradually transformed into ?-Fe2O3 and finally formed into ?-Fe2O3 after roasting,which achieves the destruction of the inverse spinal structure and promotes the migration,aggregation and precipitation of uranium atoms.U3O8 and Fe2O3 can be separated by dilute acid,80%of uranium and 99.5%of Fe2O3 can be recovered under experimental conditions.(3)The only raw material consumed by the electrochemical treatment process of radioactive waste water is metallic iron.The process is simple and has no secondary pollution.It can realize the recovery of uranium resources while purifying uranium-containing wastewater,which has certain application prospects.