Charging material for blast-furnace smelting and blast-furnace smelting method

Abstract

The invention discloses a charging material for blast-furnace smelting and a blast-furnace smelting method. The charging material for blast-furnace smelting comprises components in parts by weight asfollows: 60-85 parts of alkaline sintered ore, 10-20 parts of acid pellets and 0-5 parts of geological minerals, wherein alkalinity of the alkaline sintered ore is 2.2-2.3, and alkalinity of the acidpellets is 0.2-0.4; the alkaline sintered ore is prepared from 40-50 parts by weight of vanadium bearing titanomagnetite, 5-10 parts by weight of common fine iron powder, 5-15 parts by weight of boron-bearing iron ore powder, 1-5 parts by weight of SiC powder and 6-10 parts by weight of CaO as raw materials through sintering; the acid pellets are prepared from 50-60 parts by weight of the vanadiumbearing titanomagnetite, 5-10 parts by weight of common fine iron powder, 1-2 parts by weight of magnesite, 3-5 parts by weight of dolomite and 1-2 parts by weight of bentonite as raw materials through sintering. According to the blast-furnace smelting method adopting the charging material for blast-furnace smelting, liquidity of iron slag can be guaranteed, a slag charge structure is changed, slag basicity is reduced, effective availability of the charging material for blast-furnace smelting is improved, blast-furnace smelting efficiency is improved, and smelting cost is reduced.

Description

technical field [0001] The invention relates to the technical field of blast furnace smelting, in particular to a blast furnace smelting charge and a blast furnace smelting method. Background technique [0002] The combination of high alkalinity sinter with acid pellets is currently recognized as an ideal charge structure in the world. With the rapid development of my country's iron and steel industry, the output of iron and steel continues to increase rapidly, and the demand for acid pellets in blast furnaces increases rapidly. Under the sintering conditions of high iron and low silicon (TFe grade 57%~59%, SiO2 4.0%~5.0%), with the increase of iron grade and the decrease of SiO2 content in sinter, the strength of sinter becomes worse and the particle size is smaller. Intensity, the basicity of sinter must be further improved. This makes the demand for acid pellets more urgent, but the currently commonly used acid pellets are expensive and have a degree of reduction, resul...

AI Technical Summary

Problems solved by technology

This makes the demand for acid pellets more urgent, but the currently commonly used acid pellets are expensive and have a degree of reduction, resulting in poor strength, large dosage, and high smelting costs

As a result, the blast furnace smelting process has to take the method of reducing the alkalinity of sinter to alleviate the contradiction of insufficient acidic charge

However, as the basicity of sintered ore decreases (R<1.87), the quality of sintered ore decreases significantly, which reduces the technical indicators of ironmaking.