转炉钢渣中磷的富集与富磷相长大

Distribution and Concentration of Phosphorus in Factory Converter Slags and Growth of P-concentrating Phase

采用扫描电镜、能谱分析和X射线衍射分析现场转炉钢渣中磷元素的分布,通过添加SiO_2改性剂,在1540℃下对钢渣进行重熔后冷凝,研究改性处理后钢渣中P的富集与P富集相的长大。结果表明:现场转炉钢渣中的磷主要存在于硅酸二钙(C_2S)和硅酸三钙(C_3S)两个相中,尚有少量存在于基质相中;改性处理后钢渣中没有生成C_3S相,P主要富集在一个相C_2S中,该相中P_2O_3质量分数达到6.5%。动力学研究表明:当改性钢渣分别以1,3,5℃/min冷却时,P富集相的平均粒径分别达到87,56,8μm;当冷却速率小于3℃/min能使P富集相长大到50μm以上,为后续磨矿和P富集相的分离打下基础。

The distribution of phosphorus in factory converter slags was analyzed by SEM, EDS and XRD.The slags were modified by addition of SiO2 and heated to 1 540℃ and then cooled to room temperature. The enrichment of phosphorus and the growth of phosphorus-concentrating phase in the converter slags were investigated. The results showed that the phosphorus in the factory converter slags was mostly distributed in two phases： dicalcium silicate （C2S） and tricalcium silicate （C3S） by formation of solid solution, and with a little in matrix. C3S phase did not generate in the modified slags and phosphorus was almost concentrated in phase of C2S （P-concentrating phase） in which the contents of P205 reach to 6.5%.The dynamic studies＇ results showed that： the mean grain size of phosphorus-concentrating phase reached to 87, 56, 8 um at cooling rate 1,3 5℃/min, respectively. When the cooling rate was less than 3℃/min, the phosphorus-concentrating phase grew up to 50um, that laid a good foundation for grinding and separation of P- concentrating phase.