621
Reducing Water and Energy Consumption Through Innovative
Mineral Process Flowsheet Design
Bern Klein, Chengti.e., Wang, Genzhuang Li, Giovanni Pamparana, Yang Xu, AJ Gunson
University of British Columbia, Norman B. Keevil Institute of Mining Engineering, Canada
ABSTRACT: The mining industry has strived to reduce both water and energy consumption in their operations
through several initiatives including H2Zero and Grade Engineering among others. The University of British
Columbia (UBC) has been conducting research on enabling technologies toward achieving these goals. This
paper details an innovative flowsheet design which captures findings from this research. The basic approach is to
divert waste ahead of energy and water intensive processes such as grinding and mineral separation. Technologies
to divert waste at early stages include bulk ore sorting, particle sorting, and coarse particle (flotation) separation.
In addition, energy efficient comminution technologies such as the High Pressure Grinding Rolls (HPGR) and
high speed stirred mills among others play a key role in the flowsheet. For the final tailings management, dry
stacking processes are considered. The paper incorporates the results of multiple studies from BC copper porphyry
operations to validate the water and energy savings opportunities from using the novel process flowsheet design.
A synergistic outcome is increased copper production and therefore improved resource utilization.
Keywords: Water and energy, innovative flowsheet, sensor-based ore sorting, HPGR, coarse particle flotation,
stirred milling
INTRODUCTION
Goals towards improving the sustainability of mining
include decreasing water usage, decreasing energy con-
sumption, and improving resource utilization. Copper
resources are often located in water-stressed regions and
climate change may further exacerbate water restrictions
(Northey et al., 2017). In the case of large-scale copper
mines, conventional practices involve open pit mining fol-
lowed by comminution with SAG and Ball mill circuits
(SABC) followed by mineral separation using flotation.
Reported water usage for conventional flotation-based cop-
per mines varies widely and is impacted by many variables
however, the mean global average of direct water consump-
tion is around 75 to 100 m3/t of copper, or 0.5 to 0.7 m3/t
of ore (Gunson, 2013). Specific energy consumption also
varies widely and is also dependent on a wide range of fac-
tors, but is in the range of 28 GJ/t of copper produced
(Calvo et al., 2016).
In the last decade, several technologies have been
advanced and commercialized that can potentially improve
the sustainability of mining practices. Gunson et al. (2012)
outlined a range of options to significantly reduce water
consumption at flotation-based copper mines, including
the impact of ore-sorting and dry-stack filtered tailings. A
slightly dated, but still relevant US Department of energy
report (2007), showed the distribution of energy con-
sumed for mining activities which found that on average
almost 40% of total energy used at mining operation was
for mineral processing the majority (about 80%) of which
was consumed by comminution. For mineral processing,
Reducing Water and Energy Consumption Through Innovative
Mineral Process Flowsheet Design
Bern Klein, Chengti.e., Wang, Genzhuang Li, Giovanni Pamparana, Yang Xu, AJ Gunson
University of British Columbia, Norman B. Keevil Institute of Mining Engineering, Canada
ABSTRACT: The mining industry has strived to reduce both water and energy consumption in their operations
through several initiatives including H2Zero and Grade Engineering among others. The University of British
Columbia (UBC) has been conducting research on enabling technologies toward achieving these goals. This
paper details an innovative flowsheet design which captures findings from this research. The basic approach is to
divert waste ahead of energy and water intensive processes such as grinding and mineral separation. Technologies
to divert waste at early stages include bulk ore sorting, particle sorting, and coarse particle (flotation) separation.
In addition, energy efficient comminution technologies such as the High Pressure Grinding Rolls (HPGR) and
high speed stirred mills among others play a key role in the flowsheet. For the final tailings management, dry
stacking processes are considered. The paper incorporates the results of multiple studies from BC copper porphyry
operations to validate the water and energy savings opportunities from using the novel process flowsheet design.
A synergistic outcome is increased copper production and therefore improved resource utilization.
Keywords: Water and energy, innovative flowsheet, sensor-based ore sorting, HPGR, coarse particle flotation,
stirred milling
INTRODUCTION
Goals towards improving the sustainability of mining
include decreasing water usage, decreasing energy con-
sumption, and improving resource utilization. Copper
resources are often located in water-stressed regions and
climate change may further exacerbate water restrictions
(Northey et al., 2017). In the case of large-scale copper
mines, conventional practices involve open pit mining fol-
lowed by comminution with SAG and Ball mill circuits
(SABC) followed by mineral separation using flotation.
Reported water usage for conventional flotation-based cop-
per mines varies widely and is impacted by many variables
however, the mean global average of direct water consump-
tion is around 75 to 100 m3/t of copper, or 0.5 to 0.7 m3/t
of ore (Gunson, 2013). Specific energy consumption also
varies widely and is also dependent on a wide range of fac-
tors, but is in the range of 28 GJ/t of copper produced
(Calvo et al., 2016).
In the last decade, several technologies have been
advanced and commercialized that can potentially improve
the sustainability of mining practices. Gunson et al. (2012)
outlined a range of options to significantly reduce water
consumption at flotation-based copper mines, including
the impact of ore-sorting and dry-stack filtered tailings. A
slightly dated, but still relevant US Department of energy
report (2007), showed the distribution of energy con-
sumed for mining activities which found that on average
almost 40% of total energy used at mining operation was
for mineral processing the majority (about 80%) of which
was consumed by comminution. For mineral processing,
