Iron ore sintering method with ultrahigh-proportion flue gas circulation

Abstract

The invention discloses an iron ore sintering method with ultrahigh-proportion flue gas circulation. Flue gas passing through the head of an interception part is subjected to condensation and dewatering treatment, so that the volume concentration of water vapor is smaller than or equal to 10 percent, and then the flue gas is mixed with high-O2 tail flue gas to prepare circulatory flue gas; the volume of the circulatory flue gas is controlled to account for 50-69 percent of the total column of the flue gas in a sintering machine; the temperature of the circulatory flue gas is higher than or equal to 120 DEG C, and O2 is mixed into the circulatory flue gas, so that the O2 concentration in the circulatory flue gas can meet the requirement on fuel combustion; the circulatory flue gas is introduced into a sealed flue gas hood covering the head and the middle of the sintering machine; the flue gas retained at the head and the flue gas at the middle part are discharged after being desulfured. On the premise of guaranteeing the yield of sintered ores and not affecting the quality index, the flue gas emission can be reduced by over 50 percent; meanwhile, emission of pollutants such as dust, NOx and CO in the sintered flue gas can be greatly reduced.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, in particular to an iron ore sintering method with ultra-high proportion flue gas circulation, so as to achieve the purpose of reducing emission of sintering flue gas pollutants. Background technique [0002] my country's ironmaking system is dominated by the sintering-blast furnace process. Sintering is an important process in iron and steel enterprises, and it is also a typical link with high energy consumption, high emissions, and high pollution. The amount of flue gas emitted by the sintering process accounts for 40% of the total amount of iron and steel enterprises, and the flue gas contains CO x , SO x , NO x It is the main source of air pollution for iron and steel enterprises. Therefore, it is of great significance to the sustainable development of the iron and steel industry to reduce the emission of greenhouse gases and polluting gases in the sintering process. [...

AI Technical Summary

Problems solved by technology

In order to reduce the proportion of flue gas emission, it is necessary to further increase the proportion of flue gas circulation. However, when the proportion of flue gas circulation is high, O in the circulating flue gas 2 content is reduced to a low level, resulting in incomplete combustion of fuel in the sinter layer, affecting the quality of sinter; and the H in the circulating flue gas 2 O(g) content is too high, H 2 O(g) condenses in the lower material layer, causing the material layer to be too wet and affecting the air permeability of the sintering process, resulting in slower sintering speed; at the same time, the SO in the circulating flue gas 2 The content is too high, resulting in SO 2 It is absorbed in sinter and enriched, which increases the sulfur load of blast furnace ironmaking

Therefore, high proportion of flue gas circulation reduces sinter production efficiency and sinter quality

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