【作者】 郭戌；

【导师】 王雨；

【作者基本信息】 重庆大学 ， 冶金工程， 2011， 硕士

【摘要】 面对国际铁矿石价格不断上涨带来的成本压力,开采国内贮量丰富的高磷铁矿已经成为我国钢铁企业走可持续发展道路的重要选择。转炉双联冶炼工艺是一项高效脱磷的现代钢铁生产新工艺,为冶炼高磷铁矿提供了一项重要途径。该工艺流程中脱磷转炉体系温度低,冶炼周期短,为达到高效脱磷的目的,同时考虑到高磷渣的综合利用,石灰在高磷、无氟、低碱度初期渣中的快速溶解形成具有良好脱磷能力的炉渣起着关键作用,目前这方面的研究相对较少。为此,本文针对双联法冶炼中高磷铁水工艺流程的特点,开展双联法脱磷炉中石灰溶解行为研究,对于优化转炉双联脱磷工艺,促进脱磷转炉快速成渣具有一定的理论指导意义。本文采用高温静态溶解试验法和动态旋转试验法研究了熔渣组成、温度、相对速度对石灰在高磷渣中的溶解行为的影响,分析了石灰溶解的限制性环节,并借助矿相显微镜及扫描电子显微镜（SEM+EDS）观察分析了石灰溶解过程微观界面行为,探讨了石灰的溶解机理,主要研究成果如下:①采用正交组合设计方法研究了R、Fe₂O₃、P₂O₅、Al₂O₃和Na₂O对石灰溶解行为的影响,得出石灰溶化率与组分的关系,认为高磷渣不利于石灰的溶解。②在FetO-SiO₂-CaO-P₂O₅-5%MnO-5%MgO系高磷渣中,CaO在液相中的传质是石灰溶解的限制性环节,回归出石灰溶解速度与相对速度的关系式以及j因子方程,得到CaO的传质系数为3.03×10^-4-8.97×10^-4cm/s,并通过实验获得石灰溶解活化能约为160.32 kJ/mol。③在FetO-SiO₂-CaO-P₂O₅-5%MnO-5%MgO-X渣系中,添加剂CaF₂、Na₂O、Al₂O₃对石灰溶解促进作用顺序为:CaF₂>Na₂O>Al₂O₃,从高磷渣综合利用方面考虑,可以采用Na₂O和Al₂O₃作为CaF₂的替代剂使用,但用量应加以限制。④基于对石灰在高磷渣中溶解机理分析,认为石灰基体表面附近形成的（Fe,Mn）O-CaO层是促进石灰溶解的关键所在,而（Fe,Mn）O-CaO层外的含有3CaO·P₂O₅ -2CaO·SiO₂固溶体的固液共存区域则对石灰的溶解起到抑制作用。更多还原

【Abstract】 Facing the cost pressure brought by price rising of the international iron ore, it has been an important choice for domestic steel industries to explore high phosphorus iron ore in order to pursue Sustainable Development Path. The converter duplex process is a modern and new technology for dephosphorization, which provides an important way to cost the high phosphorus iron ore. Considering the low temperature and short melting cycle of dephosphorization converter and the comprehensive utilization of high phosph- orus slag, the rapid dissolution of lime to form slag with good dephosphorization ability plays a key role in the initial slag with high-P2O5, fluorine-free and low-R. At present, the research on this aspect is relatively rare. Therefore, the dissolution behavior of lime was studied based on the characteristics of converter duplex process, which has certain theoretical meaning for optimizing dephosphorization technology and promoting slag forming speed.In the paper, the effect of slag compositions, temperature, relative speed on dissol- ution behavior of lime were studied by static erosion method and dynamic rotation experiment method, and the restrictive step of lime dissolution was discussed. Meantime, the interfacial microstructure were observed and analyzed by mineralogical microscope and scanning electron microscopy （SEM+EDS） to disscuss the dissolution mechanism of lime. The main research results are as follows:①The effect of R, Fe₂O₃ content, P₂O₅ content, Al₂O₃ content, and Na₂O content on lime dissolution behavior was studied by quadratic regression orthogonal combination design method.The regression equation between lime melting rate and slag composition was gained. It is bad for lime dissolution in high P₂O₅ slags.②In FetO-SiO₂-CaO-P₂O₅-5%MnO-5%MgO slag series with high P₂O₅, the CaO dissolution rate is controlled by CaO diffusion mass in molten slags, and The relationship between lime dissolution rate and the relative speed was returned out, and j factor equation was gained. The CaO mass transfer coefficients is about 3.03×10^-4-8.97×10^-4cm/s, and the dissolved activation energy is about 160.32 kJ/mol.③In FetO-SiO₂-CaO-P₂O₅-5%MnO-5%MgO-X slags, CaF₂, Na₂O and Al₂O₃ can promote the lime dissolution rate, and the promotion order is CaF₂>Na₂O>Al₂O₃. Therefore, Na₂O and Al₂O₃ can be used as the substitution agent for CaF₂, but the content should be controlled, considering the comprehensive utilization of high phosp- horus slag,④Based on the analysis of the dissolution mechanism of lime, the （Fe,Mn）O-CaO layer with high FeO next to the lime plays a key role in dissolution of lime, but the area of liquid-solid coexistence containing 3CaO·P₂O₅-2CaO·SiO₂ solid solution next to （Fe,Mn）O-CaO layer reduces the lime dissolution rate.更多还原