US 11,718,885 B2
Slag discharging method in process of producing ultra-low phosphorus steel and method for producing ultra-low phosphorus steel
Shucheng Zhu, Nanyang (CN); Hu Zhao, Nanyang (CN); Shaopu Xu, Nanyang (CN); Zhongbo Li, Nanyang (CN); Hongyang Li, Nanyang (CN); Yang Yang, Nanyang (CN); Zhenglei Tang, Nanyang (CN); Tao Zhang, Nanyang (CN); Qingbo Liu, Nanyang (CN); Zhanjie Zhang, Nanyang (CN); Jiheng Yuan, Nanyang (CN); Sa Yu, Nanyang (CN); Wenju Kang, Nanyang (CN); Xi Chen, Nanyang (CN); Shuai Zhang, Nanyang (CN); Bo Li, Nanyang (CN); Zhiquan Du, Nanyang (CN); Di Zhao, Nanyang (CN); Liang Li, Nanyang (CN); Peng Jiang, Nanyang (CN); Yansheng Xue, Nanyang (CN); Keyi Fu, Nanyang (CN); Yingjie Wang, Nanyang (CN); Yongqi Yuan, Nanyang (CN); Zhenzhen Dong, Nanyang (CN); Baiming Pang, Nanyang (CN); Haiming Zheng, Nanyang (CN); Liang Chen, Nanyang (CN); Weibo Quan, Nanyang (CN); Xianxing Zhu, Nanyang (CN); Gaojian Yuan, Nanyang (CN); Chun Yang, Nanyang (CN); Yong Wang, Nanyang (CN); Yibo Bai, Nanyang (CN); Gazi Li, Nanyang (CN); Yuliang Lv, Nanyang (CN); Xibin Wang, Nanyang (CN); and Yi Ren, Nanyang (CN)
Assigned to NANYANG HANYE SPECIAL STEEL CO., LTD, Henan (CN)
Appl. No. 16/635,174
Filed by NANYANG HANYE SPECIAL STEEL CO., LTD, Henan (CN)
PCT Filed May 23, 2019, PCT No. PCT/CN2019/088064
§ 371(c)(1), (2) Date Jan. 30, 2020,
PCT Pub. No. WO2020/113911, PCT Pub. Date Jun. 11, 2020.
Claims priority of application No. 201811463555.4 (CN), filed on Dec. 3, 2018.
Prior Publication US 2021/0214813 A1, Jul. 15, 2021
Int. Cl. C21C 7/00 (2006.01); C21C 7/072 (2006.01); C21C 7/064 (2006.01)
CPC C21C 7/0087 (2013.01) [C21C 7/0025 (2013.01); C21C 7/0075 (2013.01); C21C 7/072 (2013.01); C21C 7/0645 (2013.01)] 18 Claims
 
1. A slag discharging method in a process of producing ultra-low phosphorus steel, comprising:
adding lime along with molten steel, while pouring the molten steel into a steel ladle, so as to slag in advance and form basic slag;
blowing oxygen to a top of the steel ladle and blowing argon to a bottom of the steel ladle for converting;
tilting the steel ladle so that a surface of the molten steel is close to an opening of the steel ladle; and
adding a carbon-containing reducing agent so that the basic slag is foamed and overflows from the opening of the steel ladle,
wherein an oxygen supply intensity for blowing oxygen to the top of the steel ladle is 50-300 NL/(min·t), and a pressure is 0.5-2.0 MPa.