FIGURE 2 The digital images of (a) SCG, (b)NSCG , and (c) ASCG; The SEM images of (d) SCG,(e) NSCG, and (f) ASCG
Through the microscope, we observed the SCG under different atmospheres
and statistically analyzed its particle size distribution, as shown in
Figure 3. Figure 3 ( a-c ) shows that the original SCG is brown, and the
color after heat treatment in different atmospheres is black. This is
the same as the color reflected in the digital camera. Figure 3 ( d-f )
corresponds to the particle size distribution of SCG, NSCG , and ASCG,
respectively. From the distribution map, the particle size of the three
SCG showed a normal distribution, and the average particle size of the
SCG was 0.204 mm, while the average particle size of the SCG after heat
treatment in different atmospheres decreased to 0.188 and 0.186,
respectively. The decrease of particle size indicates that heat
treatment can effectively improve the grindability of SCG under the same
grinding time, especially in air atmosphere.