Method and system for preparing metallized pellet

Abstract

The invention provides a method and system for preparing a metallized pellet. The method for preparing the metallized pellet comprises the steps that an iron containing raw material, reduction coal, a fluxing agent and a binder are subjected to first mixing, so that a first mixed material is obtained; the first mixed material is subjected to first pelletizing treatment, so that a mother ball is obtained; metal iron powder and the binder are subjected to second mixing, so that a second mixed material is obtained; the mother ball and the second mixed material are subjected to second pelletizing treatment, so that the mother ball is wrapped by the metal iron powder, and a composite carbon-containing pellet with the mother ball as a core is obtained; the composite carbon-containing pellet is conveyed into a rotary hearth furnace to be distributed in many layers, and direct reduction treatment is carried out in the rotary hearth furnace, so that the metallized pellet is obtained; and the metallized pellet is subjected to ball grinding and magnetic separation treatment, so that metal iron powder and tailings are obtained. By means of the method, the distribution thickness can be effectively increased, surface pellet melting can be effectively avoided, and the metallization ratio and reduction uniformity of the multi-layer pellet are increased.

Description

technical field [0001] The invention belongs to the field of energy and metallurgy, and in particular relates to a method and a system for preparing carbon-containing pellets. Background technique [0002] The rotary hearth furnace has the characteristics of high reduction temperature, short heating time, relatively static charge and furnace bottom, etc., which can better meet the requirements of direct reduction. At present, rotary hearth furnaces are generally used to process various composite ores, low-grade complex refractory ores, and metallurgical iron-containing solid wastes. The heat required for the temperature rise and reaction of the carbon-containing pellets in the rotary hearth furnace mainly depends on the radiation heat transfer of the furnace wall and furnace gas. The material layer thickness is generally thin (~50mm) operation, resulting in low productivity of the rotary hearth furnace, which indirectly leads to low heat utilization rate in the rotary heart...

AI Technical Summary

Problems solved by technology

Now, if a thick material layer is laid in the rotary hearth furnace, it is generally necessary to increase the temperature of the rotary hearth furnace to increase the heat transfer effect, but if the temperature is too high, the pellets will melt, especially the surface layer of pellets, which will eventually deteriorate the ventilation of the charge. , the indicator becomes worse

At the same time, the furnace charge will be bonded at the bottom of the furnace, which will erode the bottom material and reduce the life of the rotary hearth furnace.

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