Method for rapidly recovering furnace condition after long-time blowing-down of blast furnace

Abstract

The invention discloses a method for rapidly recovering the furnace condition after long-time blowing-down of a blast furnace. The method comprises steps as follows: 1), blowing-down is started when a blowing-down material downwards reaches the lower edge of a furnace bosh, the stock level is 1.2m-1.5m during blowing down, and reblowing is performed after blowing-down is performed for 8-36 hours; 2), all tuyeres are opened for reblowing, coal gas is introduced for 8-10 minutes, then, the blowing rate reaches 3,200-4,000 m<3> / min, the ore batch before blowing-down is kept unchanged in the reblowing process; 3), coke load is started to be increased after the blowing rate reaches 3,200-4,000 m<3> / min, and the smelting level is adjusted to be normal after 8 hours; and 4), the iron opening time is firstly calculated according to the blast consumption of per ton of iron at 1,300 m<3> / t*Fe after reblowing, opening for iron discharging is performed after the air volume is added up to 260,000m<3>, iron slag can be firstly pelletized, and fire slag is not discharged. According to the method, the air adding speed is high, and the time is only 6.25% of original time; the load adjustment period is short, and time is shortened by 2 / 3; and the labor intensity of workers is greatly reduced, and occupational hazards such as high temperature, noise and the like are avoided.

Description

technical field [0001] The invention belongs to the field of blast furnace ironmaking, and in particular, the invention relates to a method for quickly restoring the blast furnace condition after a long-term wind shutdown. Background technique [0002] The recovery of blast furnace conditions after a long-term wind shutdown has an important impact on further digesting the hearth, quickly upgrading to the normal working conditions before the wind shutdown, and reducing process consumption as soon as possible. With the enlargement of the blast furnace and the deterioration of the quality of raw materials and fuels, it will bring more difficulties to the recovery process of the long-term blast furnace shutdown. Solve a series of problems such as furnace conditions, deterioration of working condition indicators, and excessive process consumption. The furnace condition recovery technical plan for long-term wind shutdown directly determines whether the follow-up furnace condition...

AI Technical Summary

Problems solved by technology

This type of method has the following problems: First, the process of adding air is slow due to the restoration of the furnace condition through the blocked tuyere, which also increases the labor intensity, potential safety hazards and noise pollution of the front operation of the furnace. The wind needs two shifts of 16 hours; the second is that the coke load is determined by the number of open air outlets and the air speed. Generally, it takes 16 hours to increase the air volume before considering the load, and it takes 24 hours to return to the normal coke load level; The third is that the load of coke removal during the wind shutdown is relatively large and the quantity of the wind shutdown materials has not been quantified, which not only increases the difficulty of the recovery process of the furnace condition, but also leads to excessive process consumption and unnecessary waste; The selection of opening time did not establish the concept of air volume calibration, and did not realize the slag granulation and other issues

In short, the existing furnace condition restoration scheme can no longer adapt to the high-efficiency, stable, balanced, and low-consumption production required by the current large-scale blast furnace, and it is difficult to ensure the long-term stable and smooth operation of the blast furnace