XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3835
due to the initial condition assumed, with a hold-up about
twice as large as that reached under steady-state conditions
(17.6 t for case #2), which, in turn, leads to a greater rate of
discharge of material from the mill (Figure 2a).
Figure 2 illustrates the comparison of the hold-up com-
position between case studies #1 and #2, which exhibits
the anticipated behavior. For case study #3 both effects
are added. Thus, C3 becomes even more accumulated in
the mill hold-up since it has both the lower grindability
and higher density. For C1 and C2 the effects oppose each
other: C2 has higher grindability but lower density. This
resulted in compositions like the ones from cases #1 and
#2 (Table 2).
Wet Grinding Circuit
The wet grinding circuit simulations have been performed
considering the parameters for each component presented
in Table 1. The simulation results showed that steady state
was reached after 15 minutes since the start of the simu-
lation given the initial conditions (Figure 3). Results also
showed a higher CC accumulation in the mill hold-up and
circulating load. Two opposite effects affect the accumula-
tion behavior: The different ore size distributions (FN feed
rate is finer) and grindability, which is represented by the
specific breakage rate (CC ore is easier to comminute). The
effect of a coarser fresh feed from CC ore prevails over its
higher grindability, resulting in its higher accumulation in
a) b)
0
0.2
0.4
0.6
0.8
1
0.001 0.01 0.1 1
dp (mm)
C1
C2
C3
0
0.2
0.4
0.6
0.8
1
0.001 0.01 0.1 1 dp (mm )
C1
C2
C3
Figure 1. Partition curves for each component at initial conditions (a) and after steady-state conditions have been reached (b)
in simulation case 2
a) b)
0
50
100
150
200
250
300
350
400
450
0
5
10
15
20
25
30
35
40
0 30 60 90
Time (min)
Mill hold-up
Mill discharge rate
0.2
0.3
0.4
0.5
0 20 40 60 80 100
Time (min)
C1 -Case 1
C2 -Case 1
C3 -Case 1
C1 -Case 3
C2 -Case 3
C3 -Case 3
Figure 2. Evolution of hold-up and mill discharge rate (a) and hold-up composition (b) for simulation cases #1 and #2
c
(dp)
c
(dp)
Milldischarge
r
(h)
Millhold-up
(t)
Hold-up
composition
due to the initial condition assumed, with a hold-up about
twice as large as that reached under steady-state conditions
(17.6 t for case #2), which, in turn, leads to a greater rate of
discharge of material from the mill (Figure 2a).
Figure 2 illustrates the comparison of the hold-up com-
position between case studies #1 and #2, which exhibits
the anticipated behavior. For case study #3 both effects
are added. Thus, C3 becomes even more accumulated in
the mill hold-up since it has both the lower grindability
and higher density. For C1 and C2 the effects oppose each
other: C2 has higher grindability but lower density. This
resulted in compositions like the ones from cases #1 and
#2 (Table 2).
Wet Grinding Circuit
The wet grinding circuit simulations have been performed
considering the parameters for each component presented
in Table 1. The simulation results showed that steady state
was reached after 15 minutes since the start of the simu-
lation given the initial conditions (Figure 3). Results also
showed a higher CC accumulation in the mill hold-up and
circulating load. Two opposite effects affect the accumula-
tion behavior: The different ore size distributions (FN feed
rate is finer) and grindability, which is represented by the
specific breakage rate (CC ore is easier to comminute). The
effect of a coarser fresh feed from CC ore prevails over its
higher grindability, resulting in its higher accumulation in
a) b)
0
0.2
0.4
0.6
0.8
1
0.001 0.01 0.1 1
dp (mm)
C1
C2
C3
0
0.2
0.4
0.6
0.8
1
0.001 0.01 0.1 1 dp (mm )
C1
C2
C3
Figure 1. Partition curves for each component at initial conditions (a) and after steady-state conditions have been reached (b)
in simulation case 2
a) b)
0
50
100
150
200
250
300
350
400
450
0
5
10
15
20
25
30
35
40
0 30 60 90
Time (min)
Mill hold-up
Mill discharge rate
0.2
0.3
0.4
0.5
0 20 40 60 80 100
Time (min)
C1 -Case 1
C2 -Case 1
C3 -Case 1
C1 -Case 3
C2 -Case 3
C3 -Case 3
Figure 2. Evolution of hold-up and mill discharge rate (a) and hold-up composition (b) for simulation cases #1 and #2
c
(dp)
c
(dp)
Milldischarge
r
(h)
Millhold-up
(t)
Hold-up
composition