Mechanism on Activation of Coal Gangue Admixture

Table 3

Density and specific surface area of coal gangue powder.

Mesh	Density (g/cm^3)	Specific surface area (m^2/kg)
20–100	2.446	58.30
100–180	2.406	121.15
180–300	2.394	230.21
300–400	2.378	361.07
Over 400	2.366	438.28

Note. GB/175-2007 [32] stipulated that the specific surface area of cement should not be less than 300 m²/kg. Hence, the coal gangue powder of more than 300 mesh was selected for microwave and chemical activation in the later stage.