Method for reducing vanadium-titanium magnetite powder by coal reducing gas and fluidized beds

Abstract

The invention discloses a method for reducing vanadium-titanium magnetite powder by coal reducing gas and fluidized beds. High temperature coal gas produced by a coal reducing gas system is mixed with gas of a reducing exhaust gas purification system to form reducing gas, and the reducing gas enters third-stage, second-stage and first-stage reduction fluidized beds in turn; the preheated vanadium-titanium magnetite powder enters the first-stage, second-stage and third-stage reduction fluidized beds in turn and is fluidized and subjected to reduction reaction under the action of the reversely upward reducing gas; and the obtained directly reduced iron is briquetted, titanium slag is removed, vanadium slag is extracted, and the qualified molten steel is produced. The invention integrates process modules such as coal reducing gas, iron ore powder preheating, fluidized bed reducing, briquetting, electric furnace melting separation and the like, and has the advantages of high production thermal efficiency, low cost of preparing the reducing gas, short time of reducing the iron ore powder and the like.

Description

technical field [0001] The invention relates to a process for reducing iron ore powder in a fluidized bed in the field of ironmaking, in particular to a method for reducing vanadium-titanium magnetite powder in a coal-made reducing fluidized bed. Background technique [0002] As the world's high-grade iron ore resources are decreasing day by day, using existing blast furnace technology to "forcibly" smelt vanadium-titanium magnetite composite ore will cause a large number of symbiotic elements to be wasted without rational use, and even pollute the environment . The use of fluidized bed technology is an important way at present. [0003] The application of fluidized bed technology in metallurgy began in the 1950s and 1960s, and has now become an important process in the gas-based reduction process of non-blast furnace ironmaking technology. At present, the typical fluidized processes include HIB method, Fior method, Finmet method, Carbide method and Circored method, etc. ...

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Problems solved by technology

[0004] In the prior art, in order to solve the problem of "bonding loss" of ordinary iron ore, the fine ore particle size selected by these processes is relatively large, even reaching 12mm, and for the reduction of iron ore with such a particle size, it is different from shaft furnace, Compared with rotary kiln and rotary hearth furnace, their reaction speed advantage is greatly reduced. In addition, the preparation of reducing gas in these processes is based on natural gas, and the cost is high.

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