Method and apparatus for reducing metallic pellet by using coal dust in high furnace

Abstract

The invention discloses a metallized pellets reduction method by pulverized coal and a shaft furnace. The method comprises steps of fabricating pellets of iron ore powder or powder of other metallic oxide ore, putting the pellets into the shaft furnace by a set quantity measurement, raw coal with a lower heating value bigger than or equal to 16MJ / Kg and with an ash dry basic smaller than or equal to 40% being dried and milled by an intermediate-speed coal mill until the mesh number is smaller or equal to 100 and the moisture content is smaller or equal to 0.5%, pre-heating the pulverized coal to the temperature of 80 DEG C - 150 DEG C, transferring the pulverized coal to an air-fluidized bed gas generator,mixing the water vapour and the air in proportion, the high-temperature coal gas produced by the air-fluidized bed gas generator passing through a hot precipitator, directly spraying the coal gas after that 90%-95% dust of the coal gas has been eliminated to the lower part of the shaft furnace, the upper part of a material-discharging roller participating in the reduction reaction in the shaft furnace, reducing the iron or other metallic oxide into metallized pellets.The invention has a high reduction temperature, a high reduction speed, a high exhaust physical heat and a chemical heat which is 1.5 times higher than that of the blast furnace gas, reductive cost is greatly reduced by using the middle coal with a low heating value and a high fugitive constituent as the reductive, therefore, the per-ton cost of the generated energy sources of electrical energy, coal gas and the like is lower than 1500 yuan / t.

Description

technical field [0001] The invention relates to a non-coking coal ironmaking production method, which mainly involves reducing metal oxide pellets into metallized pellets in a shaft furnace by using reducing gas produced from coal powder. Background technique [0002] At present, the output of direct reduced iron in the world has reached 60 million tons, 90% of which use CO and hydrogen produced after natural gas cracking as reducing agents. The typical method is the Midex method in the United States. Due to the limitation of natural gas resources and high cost, The reduction of metallized pellets in shaft furnaces has not been developed in our country. Contents of the invention [0003] The object of the present invention is to provide a method and equipment for directly reducing metallized pellets in a shaft furnace after pulverized coal is gasified. [0004] The technical solutions adopted are: [0005] A method for reducing metallized pellets in a pulverized coal sha...

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Problems solved by technology

[0002] At present, the output of direct reduced iron in the world has reached 60 million tons, 90% of which use CO and hydrogen produced after natural gas cracking as reducing agents. The typical method is the Midex method in the United States. Due to the limitation of natural gas resources and high cost, Reduction of metallized pellets in shaft furnaces has not been developed in our country

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