Research On Preparing The Material γ-Fe₂O₃ Using Pyrite Cinder

Pyrite Cinder is the solid waste of sulfuric acid industry, one tons sulfuric acid will bring 0.8 to 1.5 tons pyrite cinder, our country discharges 12,000,000 t pyrite cinder approximately every year. However only has 10% cinder to use in industries and so on cement making the assistance raw material approximately. Not only the use factor is low, but also the product added value is also low, limiting the large-scale reusing of pyrite cinders. the comprehensive utilization of pyrite cinder is of important significance. This is not only due to the elimination of environmental pollution,but also the recovery of iron-rich resource. And theγ-Fe₂O₃ have been made from sulfate, which is prepare from the cinders. The new process of the cinders comprehensive utilization has been developed.In a lot of metallic oxides,γ-Fe₂O₃ is put into use but is doubly focused attention upon because of whose equal gentle in magnetism,the catalysis agile many ways broad. Current magnetism precis writer material application is more and more broad, sound recording , video record and computer belt etc. all needs the fine functionγ-Fe₂O₃ magnetic particle. Since the person surpasses a paramagnetism peculiarly , electric resistance , magnetism liquid and magnetism precis writer, are as a result soft in huge magnetism, magnetism , permanent magnetism , magnetism refrigeration , huge magnetism impedance material and aspect such as magneto-optic component, magnetism probe have magnetismγ-Fe₂O₃ vastly applying a prospect.Our study based on a detailed investigation of present utilization and recovery of pyrite, according to the real experiment condition, the FeSO₄ solution was obtained from pyrite cinders by deoxidized baking, the sulfuric acid pickling and purifying process, an aqueous ferrous sulfate solution was then obtained after purifying the reducing solution, FeSO₄·7H₂O was crystallized from the ferrors sulfate by concentrating and cooling, the effect of concentration of FeSO₄ solution, the concentration of NH₃H₂O solution,titration velocity, reaction temperature, pH, dry temperature, dry time on the procreation of ferric yellow which is the middle course of theγ-Fe₂O₃ procreation was discussed. From the experiment we draw the best thickness of FeSO₄:10%;NH₃.H₂O:20%;the titration speed:10d/min;reaction temperature:25℃;PH value of solution:7.4; dry time:6h; dry temperature:90℃.the iron contents of outcome:66.80%.At the same time, we have decided the best parameter to produceγ-Fe₂O₃ by thermal treatment based on the ferric yellow. From the experiment we draw the best heat ternperature:400℃;tirne:30min; Physical phase of outcome isγ-Fe₂O₃ and the particle diameter are approximately 62nm,and the Precursor shoude be handle by Na₂CO₃ solution .Its basic parameter conformed to the correlation application standard.Compares with other related crafts, this craft has following merit: The craft easy to operate, the main correlation parameter is advantageous for the control, the energy consumption is smallest, the entire flow needs to be short, the product pHase solely even, stable. Therefore the investment cost are few, for the pyrite cinder swidespread use to provide the good foundation, has achieved the waste circulation use goals.