XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2053
time, the yield of fine-grained coal samples increased, and
the ash content showed a decreasing trend. After the lower
ash coarse-grained coal was crushed and dissociated, the ash
content of fine-grained coal samples was bound to decrease
gradually with the increase of grinding time, which in
turn led to the decrease of the ash content of –0.045 mm-
grained coal with the increase of grinding time.
Density Analysis
In order to better analyze the dissociation of raw coal after
grinding, the density composition of the grinding prod-
ucts was analyzed, and the results are shown in Figure 7–8.
From Figure 7a and b, with the increase of grinding time,
–1.35 and 1.35–1.40 g/cm3 density grade products first
increase and then decrease, while the intermediate density
grades of 1.40–1.45 and 1.45–1.50 g/cm3 first decrease and
then increase. When the grinding time increased from 5
to 10 min, the intermediate density material was milled to
make the macerals and minerals dissociated, and the inter-
mediate density material was assigned to the low density
product and the high density grade product by dissocia-
tion, respectively.
Analysis of Figure 8a shows that as the density grade
decreases, the ash content of the milled product also
Figure 6. The ash of each size under different grinding time
Figure 7. The yield of each density level under different grinding time
time, the yield of fine-grained coal samples increased, and
the ash content showed a decreasing trend. After the lower
ash coarse-grained coal was crushed and dissociated, the ash
content of fine-grained coal samples was bound to decrease
gradually with the increase of grinding time, which in
turn led to the decrease of the ash content of –0.045 mm-
grained coal with the increase of grinding time.
Density Analysis
In order to better analyze the dissociation of raw coal after
grinding, the density composition of the grinding prod-
ucts was analyzed, and the results are shown in Figure 7–8.
From Figure 7a and b, with the increase of grinding time,
–1.35 and 1.35–1.40 g/cm3 density grade products first
increase and then decrease, while the intermediate density
grades of 1.40–1.45 and 1.45–1.50 g/cm3 first decrease and
then increase. When the grinding time increased from 5
to 10 min, the intermediate density material was milled to
make the macerals and minerals dissociated, and the inter-
mediate density material was assigned to the low density
product and the high density grade product by dissocia-
tion, respectively.
Analysis of Figure 8a shows that as the density grade
decreases, the ash content of the milled product also
Figure 6. The ash of each size under different grinding time
Figure 7. The yield of each density level under different grinding time