【作者】 吴艳青；

【导师】 王书桓； 徐志荣；

【作者基本信息】 河北理工大学 ， 钢铁冶金， 2007， 硕士

【摘要】 转炉渣作为炼钢工艺过程中必然的副产品,其产量随着钢产量的增加也在大幅攀升,然而转炉渣回收利用的方法和能力极其有限。因此,如何有效地综合利用这些转炉渣,对于进一步促进我国钢铁工业的持续高效发展具有重要意义。在转炉溅渣护炉过程中,采用向转炉熔渣中加入还原剂的方法使熔渣中的有害元素磷气化脱除。通过热力学计算分析了溅渣护炉过程中气化脱磷的可行性,以及确定脱磷反应式和脱磷产物,用硅质还原剂气化脱磷,气化脱磷反应的主要还原产物是P4气体。热力学分析表明,随着温度的上升,P4的平衡分压随之减小,当T>1873K时,降低的幅度很小,因此,在一般溅渣温度范围内,温度通过热力学因素对气化脱磷反应产物P4平衡分压影响较小;适当提高FeO含量有利于气化脱磷反应的进行;适当降低熔渣碱度易于气化脱磷反应的顺利进行。高速流动的氮气,使得反应产物的分压降低,反应向着有利于生成P4气体的方向进行,使气化脱磷反应在溅渣护炉过程中顺利进行。动力学分析了脱磷反应的物理模型,界面反应速度模型、P2O5的扩散速度模型等。进行正交实验,确定影响气化脱磷的主要因素。通过正交实验显著性分析可知,在影响转炉渣气化脱磷的炉渣成分因素中温度对气化脱磷率的影响最大,FeO含量次之,碱度最小,确定了最佳炉渣还原条件AⅣCⅢEⅡ,即:T=1923K,FeO%=19%,R=2.7。在1773K～1923K温度范围内,气化脱磷率随着温度的升高而增大;当13%<FeO%<19%时,脱磷率随着FeO含量增加而上升,当19%<FeO%<25%时,脱磷率随着FeO含量增加而下降;当2.4<R<3.6时,气化脱磷率随着碱度的升高变化不明显。在最佳炉渣条件下进行氮气流量的单因素实验,增加氮气流量,气化脱磷率升高,最高可以达到81.23%。更多还原

【Abstract】 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 AⅣCⅢEⅡ, 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.更多还原