液渣成分和硅酸二钙颗粒含量对铁水预处理非均相脱磷剂脱磷能力的影响

Effect of Liquid Slag Composition and Dicalcium Silicate Content on Dephosphorization Capacity of Nonhomogeneous Fluxes for Hot Metal Pretreatment

高磷铁水预处理脱磷的难题是脱磷剂用量太大、温降太多,急需研究脱磷能力强的脱磷剂。含有固体颗粒和液渣的非均相脱磷剂比仅含液渣的均相脱磷剂的脱磷能力强很多。为此,针对磷的质量分数为0.5%的高磷铁水,应用FactSageTM热力学软件优选出脱磷能力强的3种液渣,添加不同数量的硅酸二钙颗粒配制非均相脱磷剂试样,脱磷剂和熔铁在1 560℃下反应6h,测定熔铁中的平衡磷含量,用以评价其脱磷能力,然后在1 400℃下进行了铁水脱磷预处理试验。研究结果表明,随着硅酸二钙颗粒含量的增加,非均相脱磷剂的脱磷能力明显改善;采用非均相脱磷剂有助于减少渣量和控制反应器内衬的侵蚀;采用非均相脱磷剂对铁水脱磷,仍然需要控制较高的渣铁界面FetO浓度。

The difficulties in dephosphorization pretreatment of high phosphorous content hot metal are too many of flux consumption and too much of temperature drop, and therefore, it is desperately needed to study dephosphori- zation fluxes with higher capacity. The operational practice and previous investigations show that the dephosphori- zation capacity of nonhomogeneous flux consisted of solid particles and liquid slag is much higher than that of ho- mogenous one consisted of solely liquid slag. To this end, aiming at the high phosphorus content hot metal with 0.5% P （mass percent）, three kinds of liquid slag with higher dephosphorization capacities were selected by ap- plying the FaetSageTM thermodynamic software, test samples of nonhomogeneous flux were made by adding differ- ent amounts of dicalcium silicate, the flux reacted with molten iron for 6 h at 1 560 ℃, the equilibrium phosphorus contents in the iron was measured, being employed to evaluate their dephosphorization capacities, and then hot metal dephosphorization pretreatment experiments were conducted at 1 400 ℃. The results from this investigation revealed that the dephosphorization capacity of nonhomogeneous flux is improved significantly with the increase in the content of dicalcium silicate particles, the use of nonhomogeneous flux is helpful in the decrease of flux con- sumption and the control of corrosion of reactor linings, and that to control higher Fet O content at the interface between metal and slag is still required when using nonhomogeneous flux for hot metal dephosphorization.