XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 627
consumption. On a per ton of copper produced basis, the
water consumed decreased from 287.6 m3/t to 64.2 m3/t,
which is an 78% reduction. The high consumption per
tonne of copper produced for the base case reflects the low
grade of the ore (0.3%), which is common for copper min-
ing regions such British Columbia, Canada. From Table 6
and Table 7, it can be seen that the main contributors to the
reduction in water consumption resulted from dewatering
of the coarse particle flotation tailings and the dewatering
of the fine flotation tailings.
An alternative scenario to the proposed flowsheet
would have been to reject the particle sorting circuit fines
(–5 cm). This low-grade stream had a copper content of
0.15%. Rejection would have decreased the tonnage to the
wet tonnes processed from 47,435 tpd to 39,485 tpd with
a corresponding grade increase from 0.40% Cu to 0.45%.
Table 5. Summary of mass, water and energy balance
Description Unit
Base
Flowsheet*
Future
Flowsheet†
Difference Relative
to the Base Case
Water Consumption
Per tonne ore processed m3/t ore 0.68 0.20 -70%
Per tonne copper produced m3/t copper 287.6 64.2 -78%
Energy consumption
Per tonne of ore processed kWh/t ore 33 23 -30%
Per tonne copper produced kWh/t copper 14,021 7,347 -48%
Metal Production tpd 128.3 162.1 26%
*water consumption based on the tonnage at SAG mill screen undersize throughput
† water consumption based on the tonnage at HPGR screen undersize throughput
Table 6. Base case flowsheet—mass, water and energy balances
Mass and Water Balance Metal Balance Energy Balance
Dry
Solids,
t/h
%Solids,
%
Water,
t/h
Cu,
%
Cu,
t/d
Specific
Energy,
kWh/t
Load,
kW
Annual
Consumption,
MWh
Crushing circuit 0.4 1,111 7,300
Primary Crusher Discharge 2,778 97 86 0.30 150
SAG Mill Circuit 10 22,645 182,500
SAG Mill Screen Undersize 2,264 65 1,219 0.30 150
Ball Mill Circuit 18 40,761 328,500
Primary Cyclone Overflow 2,264 40 3,397 0.30 150
Rougher Flotation Circuit 2 4,529 36,500
Rougher Feed 2,264 35 4,205 0.30 150
Rougher Concentrate 340 30 793 1.80 135
Rougher Tailings 1,925 36 3,413 0.03 15
Regrind Circuit 20 6,793 54,750
Regrind Cyclone Overflow 340 20 1,359 1.80 135
Cleaner Flotation Circuit 2.5 849 6,844
Cleaner Feed 340 15 1,925 1.80 135
Cleaner Concentrate 24 10 214 24.43 128.3
Cleaner Tailings 316 16 1,711 0.08 6.8
Concentrate Dewatering 20 476 3,833
Concentrate Thickener Feed 24 10 214 24.43 128.25
Filter Product 24 90 2.6 24.43 128.25
Tailings Dewatering 2 4,481 36,117
Final Tailings 2,241 30 5,124 0.04 21.75
Water Loss (Fresh Water Demand) 1,537.1
consumption. On a per ton of copper produced basis, the
water consumed decreased from 287.6 m3/t to 64.2 m3/t,
which is an 78% reduction. The high consumption per
tonne of copper produced for the base case reflects the low
grade of the ore (0.3%), which is common for copper min-
ing regions such British Columbia, Canada. From Table 6
and Table 7, it can be seen that the main contributors to the
reduction in water consumption resulted from dewatering
of the coarse particle flotation tailings and the dewatering
of the fine flotation tailings.
An alternative scenario to the proposed flowsheet
would have been to reject the particle sorting circuit fines
(–5 cm). This low-grade stream had a copper content of
0.15%. Rejection would have decreased the tonnage to the
wet tonnes processed from 47,435 tpd to 39,485 tpd with
a corresponding grade increase from 0.40% Cu to 0.45%.
Table 5. Summary of mass, water and energy balance
Description Unit
Base
Flowsheet*
Future
Flowsheet†
Difference Relative
to the Base Case
Water Consumption
Per tonne ore processed m3/t ore 0.68 0.20 -70%
Per tonne copper produced m3/t copper 287.6 64.2 -78%
Energy consumption
Per tonne of ore processed kWh/t ore 33 23 -30%
Per tonne copper produced kWh/t copper 14,021 7,347 -48%
Metal Production tpd 128.3 162.1 26%
*water consumption based on the tonnage at SAG mill screen undersize throughput
† water consumption based on the tonnage at HPGR screen undersize throughput
Table 6. Base case flowsheet—mass, water and energy balances
Mass and Water Balance Metal Balance Energy Balance
Dry
Solids,
t/h
%Solids,
%
Water,
t/h
Cu,
%
Cu,
t/d
Specific
Energy,
kWh/t
Load,
kW
Annual
Consumption,
MWh
Crushing circuit 0.4 1,111 7,300
Primary Crusher Discharge 2,778 97 86 0.30 150
SAG Mill Circuit 10 22,645 182,500
SAG Mill Screen Undersize 2,264 65 1,219 0.30 150
Ball Mill Circuit 18 40,761 328,500
Primary Cyclone Overflow 2,264 40 3,397 0.30 150
Rougher Flotation Circuit 2 4,529 36,500
Rougher Feed 2,264 35 4,205 0.30 150
Rougher Concentrate 340 30 793 1.80 135
Rougher Tailings 1,925 36 3,413 0.03 15
Regrind Circuit 20 6,793 54,750
Regrind Cyclone Overflow 340 20 1,359 1.80 135
Cleaner Flotation Circuit 2.5 849 6,844
Cleaner Feed 340 15 1,925 1.80 135
Cleaner Concentrate 24 10 214 24.43 128.3
Cleaner Tailings 316 16 1,711 0.08 6.8
Concentrate Dewatering 20 476 3,833
Concentrate Thickener Feed 24 10 214 24.43 128.25
Filter Product 24 90 2.6 24.43 128.25
Tailings Dewatering 2 4,481 36,117
Final Tailings 2,241 30 5,124 0.04 21.75
Water Loss (Fresh Water Demand) 1,537.1