College of Metallurgy and Energy of North China University of Science and Technology, Hebei Key Laboratory of Modern Metallury Technology, Tangshan 063009, Hebei, China
The effects of different conditions on the equilibrium species about high-phosphorus hematite were investigated by Fact Sage6.4 thermodynamic analysis software. And some experiments were made to verify the thermodynamic analysis data. The results show that the existence forms of gas phosphorus were different at different temperatures,a rise of temperature enhances the phosphorus removal. The right amount of SiO2 concentration can reduce the onset temperature of carbothermic reduction of fluorine calcium phosphate,when the SiO2 concentration is high,the phosphorus removal were restricted by the produced silicate melts. When the C concentration is low,phosphorus is still contained in the fluorine calcium phosphate,when the C concentration is high,phosphorus is reduced to form FeP. Cl2 can react with P2 to produce PCl3,when the temperature is low,the dephosphorizing product is PCl3,when the temperature is high,the first dephosphorizing product is P2,changes the dephosphorizing product to produce PCl3 need higher concentration of Cl2. Experimental verification was conducted by using simultaneous thermal analyzer,the experiment results are in good agreement with those of the thermodynamic analysis.