Research On The Reduction Of Iron Ore Coal Mixed Pellets Of High Phosphorus Hematite By Microwave

There are 7,000 million ton high phosphorus oolitic hematite in our country. The type of iron ore has been not used significantly because it is high phosphorus and difficult to be selected and smelted. Microwave application in synthesis of organic chemistry, sintering of ceramics and metallurgy has been more and more important because of thermal effects and non-thermal effects of microwave. In order to make full use of high phosphorus oolitic hematite, a research on dephosphorization and raising the grade of iron for high phosphorus oolitic hematite by the reduction of iron ore coal mixed pellets dealt with microwave was carried out.In order to study the influence of non-thermal effects of microwave on iron ore coal mixed pellets of high phosphorus oolitic hematite, they were dealt with the industry microwave oven which had four different microwave powers. It could obtain the best technological parameter through the analysis of degree of reduetion. The results showed that the degree of reduction of iron ore coal mixed pellets which were dealt with microwave was improved obviously.Based on the analysis of the thermodynamic and dynamic properties of high phosphorus oolitic hematite, the influence of the molar ratio of carbon and oxygen, alkalinity, temperature of reduction and reducing time on dephosphorization rate and iron yield were studied by the method of orthogonal experiment. The results showed that the dephosphorization rate and iron yield of iron ore coal mixed pellets of high phosphorus oolitic hematite dealt with microwave could be obtained 85% and 90% by the way of direct reduction and a further fine-grinding and magnetic separation.Based on the data of experiments, the mechanism of the action of microwave and iron ore was studied from the molecular orbital theory and surface free energy. The results showed that the microwave radiation could be effect on the molecular orbital. It could improve the energy of molecular orbital and descend the activation energy of molecular orbital. So it availed the reduction process of the iron ore coal mixed pellets. The surface free energy of high phosphorus oolitic hematite could also be improved by microwave radiation. It could increase the adsorption ability between solid and gas surface and was benefit to the reduction process.Through the analysis of experiments and mechanism this paper want to explore a new way of using high phosphorus oolitic hematite by the combination of carbothermal reduction and magnetic separation. It has a great sense to alleviate the pressure of import and protect the persistent and stable development of steel industry.