Oxygen blast furnace iron-making process adopting water-coal-slurry as fuel

Abstract

The invention belongs to the field of ferrous metallurgy and relates to a blast furnace iron-making process using water-coal-slurry as fuel and reducer for iron-making. The process using water-coal-slurry is simple and safe, and the injecting process of water-coal-slurry provides convenience for accurate control and precise measurement. A water-coal-slurry oxygen blast furnace utilizes normal-temperature oxygen and water-coal-slurry as fuel which is injected into the blast furnace so as to partially displace coke and coal dust; the injected amount of oxygen is 200 to 500 Nmt HM, the injected amount of water-coal-slurry is 200 to 400 Nm / t HM, the required weight ratio between coal and water in the water-coal-slurry is 7:3, and the required thermal value of the water-coal-slurry is larger than 20 MJ / kg. The water-coal-slurry is decomposed and burnt to generate water-gas reaction in a circulation zone of a blast-furnace tuyere, the absorbed heat can be adopted to solve the problem of 'lower hot' caused by smelting with prior oxygen blast furnaces, and a large amount of gas generated by the decomposition and burning of the water-coal-slurry raises and can relieve the problem of 'upper cold' caused by the full-oxygen injection of the blast furnace; and the water-coal-slurry oxygen blast furnace contains rich H2 so as to enhance the penetrating power and reduction performance of blast-furnace coal gas, raise the indirect reduction degree of the blast furnace and reduce the emission amount of CO2 by 200 to 500 Nm / t HM. The process reduces both manufacturing cost and pollution to environment.

Description

technical field

[0001] The invention belongs to the field of ferrous metallurgy. The invention is suitable for the blast furnace ironmaking process and relates to a blast furnace ironmaking process using coal water slurry as ironmaking fuel and reducing agent. Background technique

[0002] At present, more than 90% of pig iron in my country is produced by blast furnaces. The current traditional blast furnaces are loaded with ore and coke from the top of the furnace, and hot air and coal powder are injected from the tuyeres at the same time. This production process has the following problems to be solved: First, the blast furnace blast brings a large amount of inert gas N 2 , the proportion of CO in the shaft gas is less than 40%, the reduction of iron ore in the shaft is insufficient, and a large amount of FeO needs to be directly reduced with carbon in the high-temperature area of ​​the lower part of the blast furnace, resulting in a large consumption of coke and increasin...

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