Sinter mixture granulating method

Abstract

A sinter mixture granulating method comprises following steps: 1) a blending ore is applied as a granulating raw material; 2) the blending ore is segmented into two parts according to a particle fraction of 3.0-4.0 mm. The blending ore whose particle fraction is less than 3.0-4.0 mm is subjected to a primary and a secondary mixing granulation with other conventional ingredients of preparing a sinter mixture. 3) the particles obtained from the secondary mixing granulation are added into the blending ore having the particle fraction greater than 3.0-4.0 mm obtained by the segmentation before, and subjected to a tertiary mixing granulation. The method can improve granulating effects for the sinter mixture, improve permeability of a material layer in a sintering process, optimize a sintering state and reach an ideal producing technique index finally.

Description

technical field [0001] The invention relates to ironmaking and sintering technology, in particular to a granulation method of sintering mixture. Background technique [0002] In the sintering production process, in order to improve sintering productivity and yield, gradually increasing the sintering layer thickness has become the development direction of sintering technology, but there are many factors restricting the sintering layer thickness, and the core restricting link is the air permeability of the sintering material layer, and the material The original air permeability of the layer is closely related to the granulation effect of the mixture. The granulation efficiency of the mixture is high, the particle size is uniform, the average particle size is large, and the air permeability of the material layer is good. Economic and technical indicators are of great significance. [0003] The prior art of mixing and granulating the sintered mixture is mainly the granulating m...

AI Technical Summary

Problems solved by technology

Therefore, under the same conditions, small particles are less likely to be granulated into larger quasi-particles by being adhered by fine powder, and are at a disadvantage in the granulation process.

Finally, the granulation effect of the mixture is poor, the bonding powder on the surface of the large particles is easy to fall off, the small particles are difficult to granulate and grow up, the particle size is uneven, and the air permeability of the material layer is poor

[0004] In order to improve the granulation effect of the mixture, some manufacturers use a tertiary mixer. Before entering the tertiary mixer, add some limestone powder or coke powder (called flux addition or fuel addition, see search content), and then strengthen the granulation. The granulation effect of this technology is improved, but the effect is not significant

At the same time, building a new tertiary mixer will have adverse effects on system setup and input costs

[0005] In addition, there are very few manufacturers who use composite agglomeration technology (see retrieval content) in order to improve the granulation effect of the mixture, that is, use the pellet production process to process some materials that are difficult to granulate, such as dust and concentrate powder, according to the pelletization process. The advanced disc pelletizing technology creates pellets with a certain particle size and is then added to the sintering mixture for sintering. This method can significantly improve the granulation effect of the mixture, but the use of pelletizing disk pelletizing facilities requires construction and production costs. high, difficult to promote

[0006] During the granulation process of sintered mixture, large particles are easy to roll off due to their small specific surface area and small friction during the rolling process, while small particles smaller than 3mm, especially the part smaller than 1mm, due to their fine particle size , the specific surface area is large, the friction force received during the rolling process is large, and it can be wetted quickly after spraying water, causing the particles to stick together and cannot roll freely. Therefore, in the process of mixing granulation, small particles It is less likely to be granulated into larger quasi-granules by the adhesion of fine powder, and the proportion of granules made with small particles as the core is small. Large, small specific surface area, weak bonding, easy to break during transportation, because of this, the existing traditional mixing and granulation technology is difficult to achieve the desired effect

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