120t转炉高磷铁水冶炼高碳低磷钢生产实践

针对莱钢用高磷铁水冶炼高碳低磷钢容易出现终点碳过低和终点磷超标的问题,通过将脱磷渣碱度控制在1.5左右,实行双渣留渣工艺,提高前期底吹强度改善动力学条件,使用无氟化渣剂和增上滑板挡渣优化挡渣效果等措施,实现了高磷铁水冶炼低磷钢的高效生产。其中,终点磷质量分数可稳定控制在0.010%以下,脱磷率由89.80%提高到94.67%,终点碳质量分数控制在0.15%以上,钢水氧化性降低,钢包渣厚降低了40mm,精炼成白渣时间减少,满足了高碳低磷钢洁净度的要求,取得了良好的经济效益。

Production practice of high carbon and low phosphorus steel by high phosphorus hot metal in 120 t converter

According to the problem of the low carbon and phosphorus converter end point to exceed the standard during producing high carbon and low phosphorus steel with the high phosphorus hot metal in Laisteel, by controlling the dephosphorization slag basicity at about 1.5, implementing the double slag and slag- remaining process, increasing the early strength of bottom blowing to improve the dynamic conditions, using the fluorine- free slag melting agent and increasing the slide gate slag to optimize the effect of slag stopping effect, the high efficiency production of low phosphorus steel by the phosphorus hot metal was achieved. The end point phosphorus can be stably controlled under 0.010%, dephosphorization rate increased from 89.80% to 94.67%, the end point carbon mass fraction can be controlled more than 0.15%, the oxidation of the molten steel was reduced, the slag depth in ladle decreased by 40 mm, the time for the formation of white slag was reduced, the demand of the cleanliness of high carbon low phosphorus steel was met, and the good economic benefits were achieved.