Method and apparatus for producing directly reduced iron with coke oven gas

Abstract

The present invention is method and apparatus for producing directly reduced iron with coke oven gas. The method includes heating coke oven gas in a heating furnace to 950 deg.c, feeding the heated gas as reductant into vertical furnace to reduce pellet or enriched iron ore, leading out the reduced gas from the top of the vertical furnace, purifying and cooling, burning partial top gas in the heating furnace to heat the coke oven gas, and adding the rest top gas into coke oven gas for its CO2 and H2O to react with CH4 in coke oven gas to produce CO and H2. The apparatus consists of vertical furnace with double bell top, tooth-roller feeder and discharge tank, heat accumulating heating furnace, and hoisting feeding machine. The present invention has 30 % raised coke coal resource, simplified process of producing directly reduced iron, low cost and high production efficiency.

Description

technical field [0001] The invention relates to the smelting of direct reduced iron, in particular to a method for producing direct reduced iron by using coke oven gas as a reducing agent. The invention also relates to a device for producing direct reduced iron by the method. Background technique [0002] At present, the output of direct reduced iron in the world has reached more than 40 million tons, of which 90% is the use of CO and H produced by natural gas cracking. 2 As a reducing agent, its typical production method is the Midrex method in the United States. This method of producing direct reduced iron has not been developed in my country. The main reasons are: [0003] 1. my country's natural gas resources are relatively scarce and expensive. Most of them are used as chemical raw materials and civil gas, and the cost of producing direct reduced iron is too high. [0004] 2. Natural gas must be cracked to make its main component CH 4 Decomposed into CO+H 2 Only whe...

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Problems solved by technology

[0003] 1. my country's natural gas resources are relatively scarce and expensive. Most of them are used as chemical raw materials and civil gas, and the cost of producing direct reduced iron is too high.

[0004] 2. Natural gas must be cracked to make its main component CH 4 Decomposed into CO+H 2 It can only be used as a reducing agent. The cracking furnace needs a large amount of high-temperature resistant stainless steel. The process is complicated and the investment is high.

Moreover, the equipment uses a coke oven type furnace, the reduction chamber is sandwiched between the reduction gas chamber and the gas collection chamber, the distance of the reduction gas passing through the reduction chamber is short, and the contact time is short, so the utilization rate of the reduction gas is low

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