Method for blowing oxygen at converter bottom

Abstract

The invention relates to a method for blowing oxygen at a converter bottom. The method comprises the following sequential steps: I. in first decarburization phase: bottom blowing and cooling of per ton of steel in each minute utilize 0.42+ / -0.06NM3 of nitrogen or argon; top blowing of per ton of the steel in each minute utilizes 2.44+ / -0.12NM3 of oxygen; II. In second decarburization phase: the bottom blowing and the cooling of per ton of the steel in each minute utilize 0.42+ / -0.06NM3 of the nitrogen or the argon; the top blowing of per ton of the steel in each minute utilizes 2.32+ / -0.12NM3 of the oxygen; III. in third decarburization phase: the bottom blowing and the cooling of per ton of the steel in each minute utilize 0.42+ / -0.06NM3 of the nitrogen or the argon; the top blowing of per ton of the steel in each minute utilizes 1.46+ / -0.12NM3 of the oxygen; IV. in fourth decarburization phase: the bottom blowing oxygen amount of per ton of the steel in each minute is 0.24+ / -0.06NM3 and the nitrogen or the argon for cooling in each minute is 0.49+ / -0.06NM3. According to the method for blowing the oxygen at the converter bottom disclosed by the invention, the service life of the converter bottom can be prolonged by more than 400 times so that the smelting cost of stainless steel is reduced.

Description

technical field [0001] The invention relates to a method for blowing oxygen at the bottom of a converter, in particular to a method for blowing oxygen at the bottom of a K-OBM-S converter. Background technique [0002] The bottom blowing oxygen supply mode of the existing K-OBM-S converter mainly consists of four steps, and the decarburization is divided into four steps. There is a K-OBM-S converter with 82 tons of molten steel in it. The first stage of decarburization: the amount of oxygen blown at the bottom of each minute is 17NM3, the amount of nitrogen or argon used for cooling is 30NM3 per minute, and the amount of oxygen blown at the top is 190NM3 per minute; the second stage of decarburization: every minute Bottom blowing oxygen volume is 17NM3, nitrogen or argon 30NM3 per minute for cooling, top blowing oxygen 180NM3 per minute; decarburization stage three: bottom blowing oxygen volume is 17NM3 per minute, nitrogen or argon 30NM3 for cooling per minute, top blowing ...

AI Technical Summary

Problems solved by technology

(The amount of gas supply is an approximate number, and the upper and lower error is generally 1NM3) The oxygen supply time of the bottom blowing gun in this gas blowing mode is longer, especially for smelting steel types with a chromium content greater than 16%, and the addition of coke and ferrochromium is large. Oxygen time is long, resulting in a long bottom oxygen supply time. The carbon-oxidized furnace lining magnesia particles in the furnace bottom brick are seriously peeled off, and the life of the furnace bottom is low. The current average furnace life is only 250 times, which seriously affects the production capacity of the converter and high cost.