Title:
溶銑の精錬方法
Document Type and Number:
Japanese Patent JP7243414
Kind Code:
B2
Abstract:
To provide a refining method of molten iron capable of securing an appropriate intermediate slag discharge amount while avoiding slopping in molten iron pretreatment.SOLUTION: A weight percent concentration of Si in main raw materials charged in a first step is 0.20 or more and 0.80 or less. A temperature of molten iron 12 at the end of blowing in a second step is 1200°C or higher and 1450°C or lower. A weight percent concentration of C in the molten iron at the end of blowing in the second step is 3.00% or more. A weight ratio of CaO to SiO2 in slag 14 removed in a third step is 0.6 or more and 2.5 or less. The second step satisfies the following formula (1). 3.60≤g×Qt'/S-0.60×εb≤4.90...(1) where g is the gravitational acceleration [m/s2], Qt' is an excess oxygen amount [kNm3/hr] which does not contribute to the decarbonization in the top blowing, S is a surface area of the molten iron (volume in the converter÷height in the converter) [m2], and εb is a bottom blowing stirring power density [kW/t].SELECTED DRAWING: Figure 1
More Like This:
Inventors:
Taihei Saito
Shinpei Ono
Yasuhisa on-site
Shuji Nishino
Kudo Susumu
Kimi Nori
Teppei Tamura
Shinpei Ono
Yasuhisa on-site
Shuji Nishino
Kudo Susumu
Kimi Nori
Teppei Tamura
Application Number:
JP2019083741A
Publication Date:
March 22, 2023
Filing Date:
April 25, 2019
Export Citation:
Assignee:
Nippon Steel Corporation
International Classes:
C21C5/28; C21C1/02; C21C1/04
Domestic Patent References:
| JP2011144415A |
Attorney, Agent or Firm:
Patent Attorney Corporation Taiyo International Patent Office
Previous Patent: Monitoring system, notification device and notification method
Next Patent: NAIL PRINT FORMING METHOD AND NAIL PRINTING DEVICE
Next Patent: NAIL PRINT FORMING METHOD AND NAIL PRINTING DEVICE