Grinding process of fly ash

At present, in the cement industry, the coarse ash sorted from power plants is generally used as a mixture to be ground together with clinker, gypsum, etc., or the coarse ash is separately ground into ordinary fine ash and then added to cement. However, there are very few cases of processing coarse ash into ultrafine ash. Below is a brief comparison of the relevant situations of different fly ash treatment processes.

Although the process of co grinding is simple, due to the significant difference in grindability between fly ash and clinker, as well as the good flowability of fly ash itself, the crushing capacity in the mill compartment will be weakened, and fine fly ash powder will play a lining role; Excessive material flow rate greatly reduces its residence time in the mill, while fly ash has good grindability but cannot be fully ground, resulting in a high water demand for fly ash cement. The use of separate grinding technology can effectively solve the above problems, because according to the grinding characteristics of fly ash, reasonable grinding material gradation and suitable structural parameters inside the mill can be configured, and the material flow rate can be effectively controlled to achieve better grinding effects. Grinding fly ash finer is more conducive to its activity and filling effect. The unburned carbon and porous glass in fly ash can be fully ground, which is conducive to the water reduction effect of fly ash.

Research has shown that:

1. The separate grinding process can effectively improve the particle size distribution of fly ash cement, increase compressive strength and standard consistency water consumption, and reduce the comprehensive power consumption of grinding.

2. While maintaining the basic strength and workability of cement, separate grinding processes can effectively increase the content of fly ash in cement and significantly enhance the adaptability of fly ash cement to water reducing agents.

3. When producing fly ash cement using separate grinding processes, the scheme of coarse clinker component and fine fly ash component, with the same specific surface area of the prepared cement, has little difference in strength performance compared to the scheme of fine clinker component and coarse fly ash component. However, the former has significant advantages in workability, adaptability to water reducing agents, and energy consumption.