Process for producing direct reduced iron (DRI) by carrying out pure oxygen gasification on semicoke

Abstract

The invention provides a process for producing direct reduced iron (DRI) by carrying out pure oxygen gasification on semicoke. The process comprises the following steps of: (1) semicoke gasification: adding the semicoke from the top of a gasifier to react with pure oxygen injected from the lower part of the gasifier and injecting coal via an oxygen tuyere of the gasifier, wherein the injection amount is 200-350kg / t of the semicoke; the pressure of the pure oxygen injected into the gasifier is 0.5-1.0MPa; the temperature of outlet gas of the gasifier is 1000-1300 DEG C; and the gas pressure is 0.45-0.95MPa; (2) gas temperature regulation: adding the outlet gas of the gasifier via cold gas, regulating the outlet gas of the gasifier to 800-900 DEG C and reducing the dust amount below 50mg / m<3> via a thermal cyclone dust collector; (3) gas desulfurization; and (4) iron ore reduction: introducing the outlet gas undergoing temperature regulation and dust collection into the lower part of a reduction shaft for producing the DRI. The process for producing DRI by taking pure oxygen gasification of semicoke as the main characteristic has the beneficial effects that the produced DRI can be directly used for electric steelmaking; the process is better than the traditional direct-reduction ironmaking process with natural gas as the reducing agent.

Description

technical field [0001] The invention relates to a direct-reduced iron manufacturing technology, in particular to a process for producing direct-reduced iron by oxidizing semi-coke with pure oxygen, which is an energy-saving direct-reduced iron manufacturing technology. Background technique [0002] With the increasing shortage of high-quality steel scrap resources in the world, the production technology of direct reduced iron (DRI) has been paid more and more attention by the metallurgical industry. Since the 1990s, the output of direct reduced iron in the world has been increasing year by year at an annual rate of 10%. In 1970, the world's output of direct reduced iron was only 830,000 tons, and by 1997 it had reached 36.2 million tons. Due to the increase in the proportion of electric furnace steelmaking and the increase in demand for high-grade steel products, more pure raw materials such as direct reduced iron are needed to ensure the quality of steel products. Direct ...

AI Technical Summary

Problems solved by technology

Although the above-mentioned direct reduction ironmaking process based on coal gasification can be realized technically, the process is complicated and the investment is high. Under the current actual conditions in our country, it does not have good economic efficiency.

Other gasification processes that use coal as the main raw material are also difficult to meet the requirements of the shaft furnace for producing direct reduced iron

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