3606 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
and commissioning are completed for Stages 2 and 3. This
staggered timeline is reflected in Figure 6.
Stage 2: Mechanical Liberation (Ultrafine grinding)
Upon commissioning of Stages 2 (and 3 concurrently, as
described below) the flotation circuit settings will be recon-
figured to maximise recovery as opposed to grade (Point
B on the grade-recovery curve in Figure 5). When recon-
figured, 95% of gold will be recovered to concentrate at
a mass pull of 10%, yielding a feed to the IsaMill ™ and
Albion Process ™ circuit as summarised earlier in Table 2.
The target grind size was selected based on a combina-
tion of required grind energy and leach testwork results.
The results for grind sensitivity leach tests (that is, testwork
undertaken to optimise ultrafine grind size targets ahead of
the leach) are presented in Figure 7.
Based on the results a P80 of 12 µm was selected for
oxidative leaching. The concentrate from Stage 1 is received
at a P80 of 25 µm. This corresponds to a required size
reduction ratio of 2:1, thus single-stage fine grinding may
be applied using an M7,500 IsaMill ™ with an installed
motor power of 2,200 kW.
As evidenced in Figure 7, fine grinding alone did not
provide any uplift in gold recovery beyond P80 8 um. As such
Stage 2 will not be completed individually and instead it will
be combined with Stage 3 for concurrent commissioning.
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100
JC Test 1 (150 um) JC Test 2 (75 um)
Recovery (%)
Point A: Concentrate for Sale
Point B: Maximum
recovery (to oxidative
leaching)
Figure 5. Grade recovery curve for sulfide flotation testwork
Testwork &Flowsheet
Design
Installation &
commissioning
Production of Saleable
Con
Operation: Treatment of Oxides
Dore produced on site
Testwork &Flowsheet
Design
Installation &
commissioning
Testwork &Flowsheet
Design
Installation &
commissioning
Stage 1
Stage 2
Stage 3
Time
Figure 6. Staggered timeline for stagewise implementation of sulfide treatment plant
Grade(g/t)
and commissioning are completed for Stages 2 and 3. This
staggered timeline is reflected in Figure 6.
Stage 2: Mechanical Liberation (Ultrafine grinding)
Upon commissioning of Stages 2 (and 3 concurrently, as
described below) the flotation circuit settings will be recon-
figured to maximise recovery as opposed to grade (Point
B on the grade-recovery curve in Figure 5). When recon-
figured, 95% of gold will be recovered to concentrate at
a mass pull of 10%, yielding a feed to the IsaMill ™ and
Albion Process ™ circuit as summarised earlier in Table 2.
The target grind size was selected based on a combina-
tion of required grind energy and leach testwork results.
The results for grind sensitivity leach tests (that is, testwork
undertaken to optimise ultrafine grind size targets ahead of
the leach) are presented in Figure 7.
Based on the results a P80 of 12 µm was selected for
oxidative leaching. The concentrate from Stage 1 is received
at a P80 of 25 µm. This corresponds to a required size
reduction ratio of 2:1, thus single-stage fine grinding may
be applied using an M7,500 IsaMill ™ with an installed
motor power of 2,200 kW.
As evidenced in Figure 7, fine grinding alone did not
provide any uplift in gold recovery beyond P80 8 um. As such
Stage 2 will not be completed individually and instead it will
be combined with Stage 3 for concurrent commissioning.
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100
JC Test 1 (150 um) JC Test 2 (75 um)
Recovery (%)
Point A: Concentrate for Sale
Point B: Maximum
recovery (to oxidative
leaching)
Figure 5. Grade recovery curve for sulfide flotation testwork
Testwork &Flowsheet
Design
Installation &
commissioning
Production of Saleable
Con
Operation: Treatment of Oxides
Dore produced on site
Testwork &Flowsheet
Design
Installation &
commissioning
Testwork &Flowsheet
Design
Installation &
commissioning
Stage 1
Stage 2
Stage 3
Time
Figure 6. Staggered timeline for stagewise implementation of sulfide treatment plant
Grade(g/t)