Proportioning method adopted during blow-in for large and medium maintenance of blast furnace

Abstract

The invention discloses a proportioning method adopted during blow-in for large and medium maintenance or long-term banking of a blast furnace. The method comprises the following steps of: (1) feeding crossties or miscellaneous trees into a part below the central line of an air opening of a hearth and an old horse; (2) charging coke and manganese ore into a part above the air opening of the hearth and a bosh and charging limestone and dolomite serving as a flux; and (3) charging a hollow material consisting of the coke, the dolomite and the limestone into the bosh. The proportioning method ischaracterized in that: a normal material and the hollow material are charged from the lower part of a furnace body to a furnace throat; and the normal material consists of the coke, agglomerate, silica, the manganese ore, the limestone and the dolomite. Silica blocks (SiO2 is more than 50 percent, Al2O3 is less than or equal to 15 percent and no requirement on iron content is made) with high SiO2content replace block iron ore. Materials are charged in four sections from the lower part of the furnace body to the furnace throat, a coke ratio is decreased gradually, the silica ratio of each section is decreased gradually and an agglomerate ratio is increased gradually. Due to the adoption of the method, the blow-in of the blast furnace is safe, successful and rapid.

Description

technical field [0001] The invention relates to a blast furnace ironmaking process in metallurgical engineering, in particular to a batching method used when a blast furnace is opened for large and medium repairs or closed for a long time. Background technique [0002] Blast furnace smelting needs to carry out batching according to certain requirements. The raw material of the blast furnace is iron ore, the fuel is coke and coal powder, and auxiliary fuel and flux are also required. Iron ore needs to have necessary chemical composition, physical properties and metallurgical properties. [0003] The charge structure used in the normal production period of modern blast furnaces is generally: sinter + pellet + lump ore. The iron content of the sintered ore (calculated by mass percentage) is generally 50%-59%, and the iron content of the lump ore is generally 50%-64%. During the overhaul and start-up period, the batching structure is very different, because the start-up mater...

AI Technical Summary

Problems solved by technology

Its characteristic is that the sintered ore is only 44%-48%, and the metallurgical properties of the raw materials are unreasonable, which affects the start-up of the furnace and causes various difficulties in the start-up of the furnace