3898 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Baseline Process Evaluation
A baseline process simulation is generated to establish
the nominal performance of the circuit. Table 1 pres-
ents the conditioning of the baseline circuit simula-
tion, wherein the four bins (B01-B04) capacities are
referred to as unit values representing the nominal value.
All the mass flows in the circuit are normalized to refer-
ence values. Figure 3 presents the baseline simulation
results for mass flow at different points of the circuit
with both crushers operating at upper limits of CSSs
(50 mm and 20 mm) and the screen deck-1 is set to
40 mm. The process is simulated for 24 hours of opera-
tions considering one startup sequence of the process and
all initial conditions of bins as empty at the material level.
After the initial startup sequence, the process reaches into a
dynamic production operation. It can be observed that in
this simulation the CR01 is fully maximized, while CR02
is under-utilized due to the insufficient supply of mate-
rial caused by the interlocks in process operation. Due to
the varying operation of the two crushers together with
the control system response for fresh feed adjustment, the
screen experiences fluctuating loading during the opera-
tion. These fluctuations in the undersize of the screening
process create the varying feed for HPGR.
Figure 4 presents different bin levels and corresponding
interlock signals generated for SP1. In this design setup, the
capacity of bins B01 and B04 are not bottlenecks, mean-
ing, they do not trigger the interlock signal for SP1. The
first bottleneck signal was observed to be dependent on the
crusher CR01 mass flow as the level in the B02 overshoots
periodically, causing the interlock in SP1. On the other
hand, bin B03 is underutilized as the crusher CR02 does
not receive the required mass flow to run at its maximum
utilization. This also results in the bin level in B03 staying
Table 1. Baseline process variable setup for the bin sizing study
B01 Level SP 50% S01 Deck-1 40–50 mm
B02 Level SP 70% S01 Deck-2 20 mm
B03 Level SP 70% CR01 CSS 45–50 mm
B04 Level SP 70% CR02 CSS 16–20 mm
CT01-CT04 PI controller Interlock SP1 80% in any bin (On/Off)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5
Circuit Feed, Avg =0.79 [-]
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5
S01 Feed, Avg =0.72 [-]
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5
CR01 Product, Avg =0.97 [-]
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5
CR02 Product, Avg =0.82 [-]
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5
HPGR01 Product, Avg =0.88 [-]
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5
Edge Splitter Recirculation, Avg =0.43 [-]
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5 Circuit Product, Avg =0.93 [-]
Figure 3. Normalized reference simulation results for mass flow at different points of the circuit
Mass
Flow
[-]
Mass
Flow
[-]
Mass
Flow
[-]
Mass
Flow
[-]
Mass
Flow
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Mass
Flow
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Mass
Flow
[-]
Baseline Process Evaluation
A baseline process simulation is generated to establish
the nominal performance of the circuit. Table 1 pres-
ents the conditioning of the baseline circuit simula-
tion, wherein the four bins (B01-B04) capacities are
referred to as unit values representing the nominal value.
All the mass flows in the circuit are normalized to refer-
ence values. Figure 3 presents the baseline simulation
results for mass flow at different points of the circuit
with both crushers operating at upper limits of CSSs
(50 mm and 20 mm) and the screen deck-1 is set to
40 mm. The process is simulated for 24 hours of opera-
tions considering one startup sequence of the process and
all initial conditions of bins as empty at the material level.
After the initial startup sequence, the process reaches into a
dynamic production operation. It can be observed that in
this simulation the CR01 is fully maximized, while CR02
is under-utilized due to the insufficient supply of mate-
rial caused by the interlocks in process operation. Due to
the varying operation of the two crushers together with
the control system response for fresh feed adjustment, the
screen experiences fluctuating loading during the opera-
tion. These fluctuations in the undersize of the screening
process create the varying feed for HPGR.
Figure 4 presents different bin levels and corresponding
interlock signals generated for SP1. In this design setup, the
capacity of bins B01 and B04 are not bottlenecks, mean-
ing, they do not trigger the interlock signal for SP1. The
first bottleneck signal was observed to be dependent on the
crusher CR01 mass flow as the level in the B02 overshoots
periodically, causing the interlock in SP1. On the other
hand, bin B03 is underutilized as the crusher CR02 does
not receive the required mass flow to run at its maximum
utilization. This also results in the bin level in B03 staying
Table 1. Baseline process variable setup for the bin sizing study
B01 Level SP 50% S01 Deck-1 40–50 mm
B02 Level SP 70% S01 Deck-2 20 mm
B03 Level SP 70% CR01 CSS 45–50 mm
B04 Level SP 70% CR02 CSS 16–20 mm
CT01-CT04 PI controller Interlock SP1 80% in any bin (On/Off)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5
Circuit Feed, Avg =0.79 [-]
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5
S01 Feed, Avg =0.72 [-]
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5
CR01 Product, Avg =0.97 [-]
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5
CR02 Product, Avg =0.82 [-]
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5
HPGR01 Product, Avg =0.88 [-]
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5
Edge Splitter Recirculation, Avg =0.43 [-]
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Time [s] 10 4
0
0.5
1
1.5 Circuit Product, Avg =0.93 [-]
Figure 3. Normalized reference simulation results for mass flow at different points of the circuit
Mass
Flow
[-]
Mass
Flow
[-]
Mass
Flow
[-]
Mass
Flow
[-]
Mass
Flow
[-]
Mass
Flow
[-]
Mass
Flow
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