Study On Mechanism Of Dephosphorization Of High Phosphorus Iron Ore Pellet

China is rich in high phosphorus iron ore resources.In order to alleviate the shortage of ore resources,the idea of high phosphorus iron ore pellet roasting and gasification dephosphorization is put forward.High phosphorus iron ore was taken as the research object and simulated with Fact Sage thermodynamic software.According to the simulation results,pelletizing and roasting experiments were conducted to explore the influence of dephosphorization agent and key factors on gasification dephosphorization.The influence of dephosphorization agent and technological parameters on pellet quality was studied.The following conclusions are drawn:1)Phosphate minerals in steel slag with high phosphorus content are mainly calcium phosphate and coexist with silicate minerals.2)Based on the Fact Sage,analyzed the gasification advantage diagram,calculated the reaction starting temperature and simulated the influence rule of components,and determine that the theoretical dephosphorization agent is SiO₂ and CaCl₂,the theoretical appropriate addition amount is 1% and 4%,and the carbon content is about 5%.3)By changing SiO₂ and CaCl₂,the optimal addition amount of dephosphorization agent was determined to be 0.8% and 1.6%,and pelletizing and firing were carried out under the condition of C+SiO₂+CaCl₂.The optimal process condition is carbon 8%,coke powder size 0.074?0.15 mm,temperature 1250?,and dephosphorization rate of 24.1%.4)The content of SiO₂ in the compressive strength of high-phosphorus pellets increases first and then decreases;The compressive strength of pellets increases with the increases of CaCl₂.The strength first increase and then decreased with the increase of carbon content.The compressive strength of pellets increases with the increase of temperature.With the increase of coke size,the pressure resistance of pellets decreases.Under the optimum dephosphorization conditions,the pellet compressive strength of high phosphorus iron ore can reach 2103 N.Figure27;Table18;Reference 52...