Reducing furnace used for producing direct reduction iron

Abstract

The invention discloses a reducing furnace used for producing direct reduction iron. The reducing furnace structurally comprises a furnace body, and is characterized in that the outer wall of the furnace body is a fire resistant insulation layer (5), a heating plate (7) is arranged in the fire resistant insulation layer (5), and the heating plate (7) is connected with a conductive device (3); a feed inlet (4) is arranged at the top of the furnace body, and a discharge hole (1) is arranged at the bottom of the furnace body. According to the invention, after iron ores and moderate carbon (as a reducing agent) in any grade and shape are mixed, the solid state is directly reduced to sponge iron through the reducing furnace. According to the reducing furnace provided by the invention, restriction on the grade of the iron ores, and the quality and the grade of coal mine is removed, and the reducing furnace has the advantages of abundant materials, simple structure, reliable technology, excellent environmental-friendly performance, and capability of greatly reducing the production cost, in particular improving the additional value in a production process.

Description

technical field [0001] The invention relates to a reduction furnace for direct reduced iron production, which belongs to the technical field of direct reduced iron processing. Background technique [0002] my country's iron and steel industry has developed rapidly and has become the world's largest steel producer and steel consumer. In 2011, the steel output exceeded 700 million tons, and the annual demand for scrap steel was more than 90 million tons, and the demand for reduced iron was 5 million tons (of which imported reduced iron was more than 4 million tons), but the output of direct reduced iron in my country is less than half a month in India. As a result, steel companies have a large shortage of direct reduced iron, and have to spend a large amount of foreign direct reduced iron at a high price. Therefore, my country is not a strong country in steel, and steel products are not competitive in the international market. In terms of steel varieties and quality, they are ...

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Problems solved by technology

[0005] The downdraft kiln developed earlier in my country, and its characteristics are: less investment, quick start-up, low cost, flexible scale, simple operation, low requirements for raw materials, but its product quality is poor and unstable, low production efficiency, high energy consumption, High labor intensity, poor operating environment, serious environmental pollution, backward equipment level, fully manual operation, no mechanization at all, but because of the low investment and some small enterprises are using it, the country does not advocate the use

[0006] Process characteristics of rotary kiln: high degree of mechanization, high operating environment, light pollution, but there are also high product costs, large investment, prone to loop failure, low product quality, and low filling factor (generally 10%- 20%), high product differentiation rate

Strict requirements on raw materials and reducing agents, low production efficiency, low thermal efficiency and other shortcomings, several domestic companies have used it, but none of them have been very successful

[0007] The traditional tunnel kiln process must use expensive refractory tanks, which is backward in technology and high in energy consumption (500-650 kg of coal for reduction and 450-550 kg of coal for heating are consumed per ton of direct reduced iron), and the reduction time is long ( 48-76h), high labor consumption, unstable product quality, high production and operation costs, and poor sales. This process also has serious environmental pollution (reduced coal ash, waste reduction tanks and other solid waste and dust), and the Disadvantages such as high raw material requirements (TFe≥66%)

[0008] All the above-mentioned direct reduction iron technologies at home and abroad cannot use low-grade ore, powder and iron-containing waste to directly reduce high-grade reduced iron products

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