624 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Of the bulk ore sorting products that are to be further
processed, 70% (37,100tpd) were sorted as high-grade ore
(above 0.3% copper grade) which reported to the further
comminution and processing and 30% (15,900tpd) were
sorted as marginal (0.1–0.3%) which would be crushed,
screened, and further upgraded by particle ore sorting. The
average grade of the high-grade stream was 0.45% and the
average grade of the marginal stream was 0.14% (Table 1).
Particle Sorting of Marginal Ore
For particle sorting, the marginal material (15,900 tpd) was
sent to crushing to prepare streams for parallel particle sort-
ing systems (25 mm to 50mm and 50mm to 100 mm).
The fines (–25 mm) were recombined with particle sorting
product for comminution and downstream processing. The
mass split to fines was estimated to be 50%, such that 7,950
tpd reports to the particle sorting plant. For the purpose of
this study, it was assumed the fines and particle sorting feed
grade are similar at 0.15% Cu. In many cases, the grade of
fines can be enhanced, however, this is ore dependent.
To assess particle sorting performance, a 400 kg sam-
ple of low-grade material was screened into size fractions
for testing using x-ray fluorescence sensors. Based on test
results, particle sorting rejected 70% of the material that
contained 0.01% Cu (Xu, 2024). The sorting product
(2,385 tpd) grade was increased to 0.38% Cu (Table 2).
HPGR Comminution
Comminution technologies such as HPGR are well known
to reduce energy consumption. Several HPGR studies have
been conducted at UBC on copper ores from different
deposits, which is the basis for selecting operating condi-
tions and estimating specific energy requirements (Wang,
2013 Wang, 2021 Pamparana, 2024). For the proposed
flowsheet, BOS High Grade, Particle Sorting product and
fines are combined ahead of HPGR comminution. The
BOS high-grade material is fed to a conventional primary
crusher to achieve a suitable size reduction beforehand. The
combined products then report to a cone crusher in closed
circuit with a screen to prepare HPGR feed. The feed rate
to the HPGR is 47,435 tpd with a grade of 0.40% Cu. The
HPGR is operated in a closed circuit with a screen size of
4 mm. The specific energy for the HPGR circuit includ-
ing conveyor belts and screens is estimated at 5.0 kWh/t to
reduce the particle size from F80 of 40 mm to P80 of 2 mm
(Pamparana et al., 2023) (Table 3).
Table 1. Bulk ore sorting analysis
Material Stream Mass Yield Tonnage per day Cu Grade, %Copper Tons per day
Base Waste 200% 100,000 ~0.05 /
Base Ore 100% 50,000 0.3 150.0
Ore recovered from Waste 12% 12,000 0.35 42.0
Waste rejected from Ore 18% 9,000 0.02 1.8
Bulk Ore Sorting products for processing 106% 53,000 0.36 190.2
High-Grade Ore Stream (0.3%) 74% 37,100 0.45 168.7
Marginal Ore Stream (0.1–0.3%) 32% 15,900 0.14 21.5
Table 2. Particle ore sorting analysis
Material Stream Mass Yield Tonnage per day Cu Grade, %Copper Tons per day
Marginal Ore (0.1–0.3%) 100% 15,900 0.14 21.5
Marginal Ore Fines (-25mm) 50% 7,950 0.15 11.9
Particle Sorting Feed 50% 7,950 0.12 9.6
Particle Sorting Ore (Accepts) 15% 2,385 0.38 9.1
Particle Ore Sorting Reject 35% 5,565 0.01 0.6
Table 3. HPGR feed components
Material Stream Mass Yield Tonnage per day Cu Grade, %Copper Tons per day
High-Grade BOS stream 78% 37,100 0.45 168.7
Particle Sorting Ore (Accepts) 5% 2,385 0.38 9.1
Marginal Ore Fines 17% 7,950 0.15 11.9
Combined HPGR Feed 100% 47,435 0.40 189.6
Of the bulk ore sorting products that are to be further
processed, 70% (37,100tpd) were sorted as high-grade ore
(above 0.3% copper grade) which reported to the further
comminution and processing and 30% (15,900tpd) were
sorted as marginal (0.1–0.3%) which would be crushed,
screened, and further upgraded by particle ore sorting. The
average grade of the high-grade stream was 0.45% and the
average grade of the marginal stream was 0.14% (Table 1).
Particle Sorting of Marginal Ore
For particle sorting, the marginal material (15,900 tpd) was
sent to crushing to prepare streams for parallel particle sort-
ing systems (25 mm to 50mm and 50mm to 100 mm).
The fines (–25 mm) were recombined with particle sorting
product for comminution and downstream processing. The
mass split to fines was estimated to be 50%, such that 7,950
tpd reports to the particle sorting plant. For the purpose of
this study, it was assumed the fines and particle sorting feed
grade are similar at 0.15% Cu. In many cases, the grade of
fines can be enhanced, however, this is ore dependent.
To assess particle sorting performance, a 400 kg sam-
ple of low-grade material was screened into size fractions
for testing using x-ray fluorescence sensors. Based on test
results, particle sorting rejected 70% of the material that
contained 0.01% Cu (Xu, 2024). The sorting product
(2,385 tpd) grade was increased to 0.38% Cu (Table 2).
HPGR Comminution
Comminution technologies such as HPGR are well known
to reduce energy consumption. Several HPGR studies have
been conducted at UBC on copper ores from different
deposits, which is the basis for selecting operating condi-
tions and estimating specific energy requirements (Wang,
2013 Wang, 2021 Pamparana, 2024). For the proposed
flowsheet, BOS High Grade, Particle Sorting product and
fines are combined ahead of HPGR comminution. The
BOS high-grade material is fed to a conventional primary
crusher to achieve a suitable size reduction beforehand. The
combined products then report to a cone crusher in closed
circuit with a screen to prepare HPGR feed. The feed rate
to the HPGR is 47,435 tpd with a grade of 0.40% Cu. The
HPGR is operated in a closed circuit with a screen size of
4 mm. The specific energy for the HPGR circuit includ-
ing conveyor belts and screens is estimated at 5.0 kWh/t to
reduce the particle size from F80 of 40 mm to P80 of 2 mm
(Pamparana et al., 2023) (Table 3).
Table 1. Bulk ore sorting analysis
Material Stream Mass Yield Tonnage per day Cu Grade, %Copper Tons per day
Base Waste 200% 100,000 ~0.05 /
Base Ore 100% 50,000 0.3 150.0
Ore recovered from Waste 12% 12,000 0.35 42.0
Waste rejected from Ore 18% 9,000 0.02 1.8
Bulk Ore Sorting products for processing 106% 53,000 0.36 190.2
High-Grade Ore Stream (0.3%) 74% 37,100 0.45 168.7
Marginal Ore Stream (0.1–0.3%) 32% 15,900 0.14 21.5
Table 2. Particle ore sorting analysis
Material Stream Mass Yield Tonnage per day Cu Grade, %Copper Tons per day
Marginal Ore (0.1–0.3%) 100% 15,900 0.14 21.5
Marginal Ore Fines (-25mm) 50% 7,950 0.15 11.9
Particle Sorting Feed 50% 7,950 0.12 9.6
Particle Sorting Ore (Accepts) 15% 2,385 0.38 9.1
Particle Ore Sorting Reject 35% 5,565 0.01 0.6
Table 3. HPGR feed components
Material Stream Mass Yield Tonnage per day Cu Grade, %Copper Tons per day
High-Grade BOS stream 78% 37,100 0.45 168.7
Particle Sorting Ore (Accepts) 5% 2,385 0.38 9.1
Marginal Ore Fines 17% 7,950 0.15 11.9
Combined HPGR Feed 100% 47,435 0.40 189.6