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1. (WO2018014752) PRODUCTION PROCESS FOR DEPHOSPHORIZATION OUTSIDE OF FURNACE OF MOLTEN STEEL

Pub. No.:    WO/2018/014752    International Application No.:    PCT/CN2017/092404
Publication Date: Fri Jan 26 00:59:59 CET 2018 International Filing Date: Tue Jul 11 01:59:59 CEST 2017
IPC: C21C 7/064
Applicants: TANGSHAN ZHENGFENG IRON&STEEL CO.,LTD.
唐山正丰钢铁有限公司
Inventors: ZHOU, Zhili
周志立
PENG, Guanghui
彭光辉
WANG, Kai
王凯
LI, Chunyuan
李春远
DING, Guangyou
丁广友
Title: PRODUCTION PROCESS FOR DEPHOSPHORIZATION OUTSIDE OF FURNACE OF MOLTEN STEEL
Abstract:
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.