LF精炼渣的物相及其冷却过程研究

Study on the phase and cooling process of LF refining slag

利用X射线荧光光谱仪、X射线衍射仪、扫描电镜和能谱分析仪对某厂260 t LF精炼渣的物相组成及其形貌特征进行研究,并用热力学软件FactSage对其冷却过程中物相的析出情况进行研究。结果表明:LF精炼渣的主要物相组成为钙铝相和钙硅相,还含有少量的Ca(OH)2和MgO。钙铝相根据是否含硫而呈现出不同的显微形貌特征;钙硅相则多呈圆形或不规则椭圆形,且物相表面为颗粒堆积状态;而MgO相为无定形状,多分布在钙硅相周围。LF精炼渣在缓慢冷却的过程中,最终会析出固溶有MgO的钙铝酸盐相(Ca3MgAl4O10)、CaO、少量的Ca2(Al,Fe)2O5以及γ-C2S等物相,且各物相的析出温度分别为1 280,1 100,1 100,850℃。

X-ray fluorescence,X-ray diffraction, SEM and EDS were used to study the phase composition and microstructure of the 260 t ladle furnace refining slag of a steel mill, and the thermodynamic software FactSage was used to study the precipitation process of each precipitated phase in the cooling process of the LF refining slag. The re- sults indicate that the main phases of the LF refining slag are calcium aluminum phase and calcium silicon phase, and also a small amount of Ca（OH）2 and MgO： Calcium alu- minum phase appears as different shapes based on whether it contents sulphur or not; calcium silicon phase mainly appears as round or irregular oval shape, and in accumula- tion state; free MgO phase has irregular shape, mainly distributed around the calcium silicon phase. In the slow cooling process of the LF refining slag, the final precipitated phases are calcium aluminate contenting MgO（Ca3 MgAl4 O10 ）, CaO, a small amount of Ca2 （Al,Fe）2O5 and γ-C2S, and the precipitating temperatures of each phase are respec- tively 1 280 ℃,1 100 ℃,1 100 ℃ and 850 ℃.