Method for manufacturing sponge iron

Abstract

The invention relates to a method for manufacturing sponge iron. The method for manufacturing sponge iron comprises the following steps of: respectively drying and crushing a ferric oxide, a reducing agent, a desulfurizing agent, an activating agent to 50-100 meshes, mixing the raw materials according to a weight ratio being 1:(0.2-0.6):(0.1-0.3):(0.05-0.15), adding the mixture to a kiln body to carry out a reduction reaction, and cooling down to produce sponge iron products. The ferric oxide is any one of iron concentrate powder, iron-containing dust slime, phosphorus iron oxide and gravitational dust-removed powder, wherein the reducing agent is one of low-sulfur coal, coke powder and blue powdered carbon, the desulfurizing agent is lime powder, and the activating agent is silicon iron powder; the heating time is controlled within 8-12h, the heating temperature is within 1,000-1,250 DEG C, and the density of the sponge body products is 6-7g / cm<3>. The method for manufacturing sponge iron, disclosed by the invention, has the advantages of improving conditions of mass transfer and heat transfer, creates more beneficial conditions for chemical reactions; the activating agent has double functions of reduction and catalysis; the complicated front-stage in-kiln process and post-stage cooling drawing process in the traditional technique are improved; industrial refuse are reduced by more than 50% as compared with that generated by an original process.

Description

technical field [0001] The invention relates to a method for manufacturing sponge iron, which is mainly aimed at the method for producing sponge iron by heating and reducing iron-based oxides. Background technique [0002] The traditional tunnel kiln sponge iron production process is to mix coke powder or low-sulfur coal, desulfurization agent or lime powder, layer with iron-containing oxides and put them into refractory tanks, and then enter the kiln at a temperature of 1100-1200°C and heat for 40-50 Hours for reduction reaction, after cooling out of the kiln out of the tank to obtain sponge iron products. During the reaction process of this process, the iron-containing raw material and the reducing agent are relatively static, and the mass transfer and heat transfer process is poor, resulting in long reaction time, uneven reaction, incomplete reaction, low product density, low metallization rate, and industrial waste including waste tanks and waste reduction. Desulfurizat...

AI Technical Summary

Problems solved by technology

During the reaction process of this process, the iron-containing raw materials and the reducing agent are relatively static, and the mass and heat transfer process is poor, resulting in long reaction time, uneven and incomplete reaction, low product density, and low metallization rate. Industrial waste includes waste tanks, waste reduction Desulfurization agent, desulfurization agent, large amount of production, complicated process and other defects

[0003] At present, both at home and abroad, the rotary kiln method is used in the reduction process, and they all hold a negative attitude. Yang Tianjun pointed out on page 251 of "Smelting Reduction" that "this kind of process equipment is huge, has extremely high requirements on ore and coal types, and has low production efficiency." Seamless, Miyun Mining and Metallurgical Company, Shandong Luzhong and other enterprises are examples of unsatisfactory production of sponge by rotary kiln process

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