The solidification mechanism of the pellets is to form the crystal bridge, compound or solid solution by the solid particle diffusion reaction of iron concentrate powder under high temperature, and recrystallize the iron ore powder particles to bond. The quality of pellets is mainly determined by the performance of raw materials, additives and the two processes of pelletizing and roasting. A large number of production practice and research results show that a reasonable preparation of raw materials and optimization is a very important part. The particle size, size composition, specific surface area, surface structure, hydrophilicity, mineral type and structure of the iron concentrate powder will influence the pelletizing process and pellet quality.
The research and practice show that the pelletizing performance of iron concentrate powder is not only -0.074mm, but the specific surface area and the surface structure are the important factors which influence the pelletizing process. The ball-making performance of -0.074mm is not good, And iron ore particle surface characteristics are closely related to the specific surface area. The specific gravity of the iron concentrate is preferably not less than 1 800 cm 2 / g, more preferably not less than 2000 to 2200 cm 2 / g, while the particle size of the concentrate is not less than 90% but less than 0.074 mm. Irregular surface morphology, containing a small amount of 0.001 ~ 0.015mm of fine particles, both can increase the specific surface area, while in the fine particles filled in the gap in the particles, the capillary is conducive to thinning, increased capillary force, thereby improving the quality of green and Quality of finished pellets.
When the nature of the raw material itself achieve good levels, the use of ore pressure ball machine or dry powder pressure ball machine for processing, can be easily processed into the required material standards. Therefore, in this respect, the factors related to the material itself, such as particle size, particle size composition, specific surface area, surface structure, hydrophilicity, mineral type and structure, are the main factors.