How To Improve The Activity Of Slag Micropowder

2022-06-22

Slag is the slag produced in the iron making process. Due to the poor grindability and low activity of the slag, the activity of the slag is generally improved by artificial physical and chemical methods. The physical activation of the slag refers to grinding the slag to a predetermined fineness. Then, its activity can be fully exerted.

Slag micropowder is an aggregate of fine particles after grinding the slag through the grinding equipment (micronization refers to the process of pulverizing solid materials into micropowder). The slag can be ground to a certain specific surface area (the fineness is too coarse, the activity will not be effectively exerted), which can increase the contact area for the hydration reaction, reduce the diffusion distance of the mass transfer process during the hydration reaction, and improve the hydration reaction.

The higher the specific surface area of grinding, the higher the hydration activity, but the slag itself has poor grindability. The traditional method of grinding to increase the specific surface area and increase the activity of the slag has high energy consumption, especially when the specific surface area is ≥ 420㎡/Kg. For example, the common slag vertical mill and ball mill on the market, both of which are the main equipment for grinding slag, but due to the continuous optimization of the grinding process, the slag vertical mill not only has low energy consumption, but also saves 30% to 40% compared with the ball mill system. At the same time, the specific surface area of the slag micropowder products produced can reach more than 420㎡/Kg, and the activity is good.

Mixing slag powder in cement production can increase the 28D strength of cement by 15%–20%, and configure 42.5 grade cement; adding slag powder in concrete production can replace 10-50% of cement, and use slag powder to replace concrete in an equal amount And the amount of cement in cement products has become the mainstream trend in the building materials industry.