Thermodynamics And Kinetics Of Gasificating Dephosphorization From Slag By Silicon Reduction

As the inevitable residual product of converter steel-making process, BOF slag's capacity is on the substantial increase along with the increment of converter steel's output, but the methods and abilities of recovery utilizing BOF slag are extremely limited. Therefore, how to effectively use them to the further promotion of durative and efficient development of China's iron and steel industry is great significance.During converter slag splashing process, the harmful elements such as phosphorus is gasificating deprivation which adding reducing agent into BOF slag. Based on thermodynamic calculations, we analyses the feasibility of gasificating dephosphorization reaction in slag splashing process, and ascertained the reaction formula and products of gasificating dephosphorization. The main deoxidize product of gasificating dephosphorization in high temperature is P4 which use siliceous reducer. Thermodynamic analysis indicates that, along with the temperature rising, balance partial pressure of P4 is depressed, but the lower level is not large, relatively lower temperature is propitious to gasificating dephosphorization reaction. In the range of slag splashing temperature, it is less influence the gasificating dephosphorization on thermodynamic factors; correct increase content of FeO is beneficial to gasificating dephosphorization; and correct reducer slag basicity is benefit for gasificating dephosphorization. The partial pressure of reaction product is falling along with high-velocity flow nitrogen, is beneficial to positive reaction, result of reaction is P4. Analysis the physical model, interface reaction velocity model, P2O5's diffusion velocity model of gasificating dephosphorization reaction by dynamics. It is determined that, which is main factor of influence gasificating dephosphorization by orthogonal experimentBy significance analyses of orthogonal experiment, it is indicated that among the four influencing factors which influence the deoxidization of phosphor, temperature is uppermost influencing factors, the content of FeO takes the second place, basicity takes the third place, The optimum condition for gasificating dephophorization during the process of slag splashing was determined, is Aâ…£Câ…¢Eâ…¡, T=1923K, FeO%=19%, R=2.7. In the range of temperatures from 1773K to 1923K, dephosphorization rate is increasing when temperature is rising; Dephosphorization rate is ascending when content of FeO is increasing, which the content of FeO is between 13% and 19%, but it is reducing between 19% and 25%; basicity effect on Dephosphorization rate is not obvious during 2.4 to 3.6. Single factor experiment reviewed that the gasificating dephophorization ratio of reduced slag can reach to 81.23% at the most under optimum condition.