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Water Efficiency Targets Are Insufficient for Good Water
Performance in Mining
Nadja C. Kunz
School of Public Policy &Global Affairs, The University of British Columbia
Shahla Muram
Norman B Keevil Institute of Mining Engineering, The University of British Columbia
ABSTRACT: In this paper, we analyzed water targets proposed by 25 of the world’s largest mining companies in
their 2022 public sustainability reports, and find an overwhelming emphasis on the pursuit of water efficiency.
We argue that this disregards the nature of mining and minerals processing operations which are located in a
range of contextual environments that create inherently different water-related risks, e.g., scarcity, flooding,
community issues, water quality concerns. We propose that there is a need for a deeper dialogue around what
characterizes a “good water performer” and highlight the important role of minerals processing engineers and
metallurgists in designing and operating facilities to reduce the water-related impacts of the mining sector in
both the short and long term.
INTRODUCTION
Water is an essential input for mining and minerals process-
ing operations, including as the primary medium for min-
erals separation and processing (Côte et al., 2010 Gunson
et al., 2012). Increasingly, mining projects are located in
regions where water is scarce, with investors expressing con-
cern that roughly two thirds of the world’s largest mines
are located in countries experiencing severe water scarcity
(Metcalf, 2013).
Given the significance of water scarcity challenges fac-
ing the sector, the industry has made significant efforts
in developing and implementing technologies that could
reduce water consumption and maximize water recycling.
For commodities that use flotation for minerals separa-
tion, such as base metals sulphide operations, significant
water losses occur through evaporation and entrainment
within tailings dams. Consequently, effective water savings
can be achieved through implementing technologies at the
‘back-end’ of the minerals processing circuit, such as thick-
eners and filter presses, which reduce the evaporative losses
of water (e.g., Cox et al., 2023). Likewise, the introduction
of processing methods at the ‘front-end’ of the circuit, such
as froth-crowding and hydro-cyclones (Pyle et al., 2022),
can allow an increase in grind size without substantively
reducing metal recovery. This results in tailings streams
that can be more easily dewatered, thereby increasing water
recycling and recovery and ultimately lowering an opera-
tion’s overall water consumption per tonne of product.
Striving towards these types of water efficiency improve-
ments are extremely important for many mining operations,
particularly those in water-stressed mining regions such as
in Chile and Australia, where the costs of water access may
be significant. However, mining operations globally face a
much broader set of water-related challenges that are heav-
ily context dependent, and are strongly linked to geogra-
phy and climate. For example, in major mining regions of
Water Efficiency Targets Are Insufficient for Good Water
Performance in Mining
Nadja C. Kunz
School of Public Policy &Global Affairs, The University of British Columbia
Shahla Muram
Norman B Keevil Institute of Mining Engineering, The University of British Columbia
ABSTRACT: In this paper, we analyzed water targets proposed by 25 of the world’s largest mining companies in
their 2022 public sustainability reports, and find an overwhelming emphasis on the pursuit of water efficiency.
We argue that this disregards the nature of mining and minerals processing operations which are located in a
range of contextual environments that create inherently different water-related risks, e.g., scarcity, flooding,
community issues, water quality concerns. We propose that there is a need for a deeper dialogue around what
characterizes a “good water performer” and highlight the important role of minerals processing engineers and
metallurgists in designing and operating facilities to reduce the water-related impacts of the mining sector in
both the short and long term.
INTRODUCTION
Water is an essential input for mining and minerals process-
ing operations, including as the primary medium for min-
erals separation and processing (Côte et al., 2010 Gunson
et al., 2012). Increasingly, mining projects are located in
regions where water is scarce, with investors expressing con-
cern that roughly two thirds of the world’s largest mines
are located in countries experiencing severe water scarcity
(Metcalf, 2013).
Given the significance of water scarcity challenges fac-
ing the sector, the industry has made significant efforts
in developing and implementing technologies that could
reduce water consumption and maximize water recycling.
For commodities that use flotation for minerals separa-
tion, such as base metals sulphide operations, significant
water losses occur through evaporation and entrainment
within tailings dams. Consequently, effective water savings
can be achieved through implementing technologies at the
‘back-end’ of the minerals processing circuit, such as thick-
eners and filter presses, which reduce the evaporative losses
of water (e.g., Cox et al., 2023). Likewise, the introduction
of processing methods at the ‘front-end’ of the circuit, such
as froth-crowding and hydro-cyclones (Pyle et al., 2022),
can allow an increase in grind size without substantively
reducing metal recovery. This results in tailings streams
that can be more easily dewatered, thereby increasing water
recycling and recovery and ultimately lowering an opera-
tion’s overall water consumption per tonne of product.
Striving towards these types of water efficiency improve-
ments are extremely important for many mining operations,
particularly those in water-stressed mining regions such as
in Chile and Australia, where the costs of water access may
be significant. However, mining operations globally face a
much broader set of water-related challenges that are heav-
ily context dependent, and are strongly linked to geogra-
phy and climate. For example, in major mining regions of
