Study On Preparation Of Fe₂O₃ From Vanadium Tailings By Resource Utilization

Vanadium tailings?VTs?are the leaching wastes in the manufacturing of V₂O₅ and most of them are piled up and dealt with a low utilization rate,resulting in waste of resources and environmental pollution.If a effective way to extract vanadium iron from vanadium residues and further to prepare Fe2O3 can be found,it is of great significance to recycle vanadium residues,improve plant efficiency and solve environmental problems.Therefore,one of comprehensive utilization ways of vanadium residues relies on the construction of a new and clean combustion technology with high efficiency to equrate Fe.It can effectively combine comprehensive utilization of resources and environmental pollution abatement,to fundamentally achieve comprehensive recycling of valuable metals,and further to realize the clean and efficient utilization of waste vanadium residues.As a kind of important inorganic non-metallic materials,because of relatively stable chemical properties,high catalytic activity,good light fastness and weather resistance and ultraviolet radiation shielding,Ferric oxide has extremely wide and important application in many fields,such as the paint and rust,the building,the electronics industry,the catalyst and the chemical industry.Especially,Ferric oxide applied catalytic performance and unique features such as the large capacity to photocatalytic degradation of color dye,and preparation for lithium-ion battery anode materials.In this paper,using waste vanadium residues.as raw materials,the factors in atmospheric acid leaching were researched.Then,based on above results,the factors in pressure acid leaching were also studied.The results showed that the highest leaching rate of iron was 31% in the atmospheric acid leaching,yet the one was 66% in the pressure acid leaching.Compared with the recovery of the atmospheric acid leaching,the leaching rate in the pressure acid leaching increased obviously.The best conditions of the pressure acid leaching are that the ratio of distilled water and H₂SO₄ addition volume is 1:3,reaction time is 2h and leaching temperature is 220?.Using the acid leaching of waste vanadium residues as material,the leaching liquid was used to prepare crystallized FeSO₄·7H₂O under normal temperature,The best conditions are that leaching temperature is 50?,reaction time is 150 mins,additive amount of iron powder is 8g.Then,glucose as the template agent,FeSO₄·7H₂O as raw material,throuh hydrothermal reaction,the hollow iron oxide particles were obtained after washing,drying and calcination.The optimum conditions are that the leaching temperature is 220?,reaction time is 12 hours,calcination temperature is 600 ?,and calcination time is 3 hours.The morphology and phase of hollow iron oxide was analyzed by SEM,TEM and XRD,and the structure was characterized by IR.The specific surface area and morphology of iron oxide was further analyzed.Through the study of the morphology analysis of iron oxide,iron oxide is a hollow spherical structure after calcining,particle size is about 0.05 ?m;the study of the specific surface area test show that the specific surface area of iron oxide is 21.327m²/g,the pore size is 3.021 nm,the pore volume is 0.04028cc/g.Finally,the results of electrochemical performance tests as the cathode materials of lithium-ion battery showed that the capacity of ferric oxide first discharged is 1198mAh/g under the current density of 100mAh/g,the initial reversible capacity is 870 mA.h,and the first coulomb efficiency is 94%.When the density of methyl orange was 20mg·L-1,experiments in the photocatalytic degradation of methyl orange were conducted..Compared with the blank test,the efficiencies of absorbance degradation and declorization increased with the augment of iron oxide quantity.Results showed that when the supply of iron oxide was 1.0 g/L,the minimum absorbance was 0.202 and the maximum decolourization rate was 87.2% after degradation of 6 hours.