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|1. (WO2018014752) PRODUCTION PROCESS FOR DEPHOSPHORIZATION OUTSIDE OF FURNACE OF MOLTEN STEEL|
|Applicants:||TANGSHAN ZHENGFENG IRON&STEEL CO.,LTD.
|Title:||PRODUCTION PROCESS FOR DEPHOSPHORIZATION OUTSIDE OF FURNACE OF MOLTEN STEEL|
A production process for dephosphorization outside of a furnace of molten steel, comprising the following process steps: (1) medium-frequency induction furnace smelting: adding steel scrap into a medium-frequency induction furnace for smelting, wherein the smelting end-point is that chemical components in mass percentage are C: 0.05-0.30% and P: ≤ 0.050%, and the temperature of the molten steel is 1550-1650ºC; and (2) dephosphorization and smelting outside of the furnace: pouring the molten steel into a ladle, and blowing the molten steel using a lime injection lance and an oxygen lance, wherein the injection rate of the lime injection lance is 10-100 kg/min, the injection amount of lime (Kg) is (the phosphorus content in % at the smelting end-point of the medium-frequency induction furnace smelting - a target phosphorus content in %) * 100 * 3.4 * the weight of the molten steel, and the injection rate of oxygen is 1-10 m3/min. The process can reduce the phosphorus content in the molten steel to the target content at a low cost by means of optimizing the production process and the injection process.