Operation technology used for maintaining direct motion of large blast furnace through low-heat state strength coke

Abstract

The invention discloses an operation technology used for maintaining direct motion of a large blast furnace through low-heat state strength coke. Local coal is used, the heat state strength of the coke is 29.8%, the O / C is 4.142, oxygen enrichment is maintained to be 15500+ / -100 m<3> / h, the oxygen enrichment rate is 4.5%-5%, the top temperature is 105+ / -5 DEG C, PT ranges from 1490 DEG C-1510 DEGC, Si ranges from 0.5-0.7, and the fuel ratio ranges from 541 kg / t-557 kg / t. The operation technology comprises the following steps that (1) the coke ratio is reduced, the blowing-in area is adjustedfrom 0.34 m<2> to 0.311 m<2>, and the air speed is 265+ / -5 m / s; (2) according to a charging rule, the air volume is reduced to 4000 Nm<3> / min,and the material speed per batch is 44+ / -1; (3) accordingto a heating rule, the molten iron temperature is 1490 DEG C+ / -10 DEG C; (4) according to a slagging rule, the blast-furnace slag basicity ranges from 1.1-1.5; and (5) according to a tapping deslagging rule, the iron notch depth is 3600 mm-3800 mm, the mud ramming quantity is 200 kg-250 kg, and the mud emitting rate is smaller than 1%. According to the new technology, the large blast furnace completely uses the low-heat state strength coke, by increasing oxygen enrichment and decreasing the air quantity, the coal gas component is improved, the bosh coal gas quantity is decreased, the blast furnace pressure difference is reduced, the air feeding rule, the charging rule, the heat rule and the slagging rule are adjusted, the direct motion of the furnace condition is maintained, a foothold iskept at the local coal resource, and the competitive power is improved.

Description

technical field [0001] The invention belongs to the technical field of large-scale blast furnace smelting pig iron, in particular to an operation process for a large-scale blast furnace to use coke with low thermal strength to maintain forward movement. Background technique [0002] Coke is the main fuel for blast furnace smelting. With the large-scale and high-efficiency smelting of blast furnaces, the quality requirements of coke become more important. However, increasing the thermal strength of coke requires the use of coking coal, which is scarce in resources, for coking, which increases the cost of molten iron. [0003] The effect of coke on blast furnace ironmaking: (1) The role of the skeleton of the furnace charge: supporting the furnace material column and improving the gas permeability of the furnace charge. Blast furnace production requires the material column to have good air permeability and liquid permeability, so that the charge can be reduced normally and the...

AI Technical Summary

Problems solved by technology

[0008] According to the coke quality requirements for 2500 cubic meters of blast furnace, CRI is less than 26%, and CSR is greater than 60%, otherwise it is difficult to achieve stable and smooth production of blast furnaces. According to the cost of coke production by blending coal with CRI less than 26%, and CSR greater than 60%, the thermal strength is calculated outside Xinjiang. The coal is at least 77%, and the coal in Xinjiang is 23%. According to the cost price, the cost of metallurgical coke is 1096.1 yuan / ton, and the cost of coke with this ratio is very high