ArticlePDF Available

Abstract and Figures

The significant increase in metal mining and the inevitability of the continuation of this trend suggests that environmental pressures, as well as related impacts, have become an issue of global relevance. Yet the scale of the impact remains, to a large extent, unknown. This paper examines the mining sector’s demands on CO2 emissions, water use, as well as demands on land use focusing on four principal metals: iron, aluminium (i.e., bauxite ore), copper, and gold. These materials represent a large proportion of all metallic materials mined in terms of crude tonnage and economic value. This paper examines how the main providers of mining data, the United Nations, government sources of some main metal producing and consuming countries, the scientific literature, and company reports report environmental pressures in these three areas. The authors conclude that, in the global context, the pressure brought about by metal mining is relatively low. The data on this subject are still very limited and there are significant gaps in consistency on criteria such as boundary descriptions, input parameter definitions, and allocation method descriptions as well as a lack of commodity and/or site specific reporting of environmental data at a company level.
Content may be subject to copyright.
Metal Mining’s Environmental Pressures: A Review
and Updated Estimates on CO2Emissions, Water Use,
and Land Requirements
Michael Tost 1,*, Benjamin Bayer 1, Michael Hitch 2, Stephan Lutter 3, Peter Moser 1ID
and Susanne Feiel 1
1Mining Engineering and Mineral Economics, Montanuniversitaet Leoben, 8700 Leoben, Austria; (B.B.); (P.M.); (S.F.)
2School of Science, Department of Geology, Tallinn University of Technology, 19086 Tallinn, Estonia;
Institute for Ecological Economics, Vienna University of Economics and Business (WU), 1020 Wien, Austria;
*Correspondence:; Tel.: +43-664-452-9872
Received: 28 June 2018; Accepted: 10 August 2018; Published: 14 August 2018
The significant increase in metal mining and the inevitability of the continuation of this
trend suggests that environmental pressures, as well as related impacts, have become an issue of
global relevance. Yet the scale of the impact remains, to a large extent, unknown. This paper examines
the mining sector’s demands on CO
emissions, water use, as well as demands on land use focusing
on four principal metals: iron, aluminium (i.e., bauxite ore), copper, and gold. These materials
represent a large proportion of all metallic materials mined in terms of crude tonnage and economic
value. This paper examines how the main providers of mining data, the United Nations, government
sources of some main metal producing and consuming countries, the scientific literature, and company
reports report environmental pressures in these three areas. The authors conclude that, in the global
context, the pressure brought about by metal mining is relatively low. The data on this subject are still
very limited and there are significant gaps in consistency on criteria such as boundary descriptions,
input parameter definitions, and allocation method descriptions as well as a lack of commodity
and/or site specific reporting of environmental data at a company level.
Keywords: mining; gold; bauxite; copper; iron ore; environmental pressure; CO2; water; land use
1. Introduction
The environmental impact of metal mining has been an issue for centuries (e.g., [
maybe even millennia. For most of this time however, these impacts have been mainly local
such as deforestation (e.g., in Saxony/Germany), water pollution (e.g., Rio Tinto/Spain), and soil
contamination (e.g., in Bleiberg/Austria).
Today, largely due to the “great acceleration” of economic growth after World War II [
] and
ever-increasing globalization of trade, global metal mining is increasing significantly (e.g., [
] (p. 10))
and environmental pressures such as land and water use, as well as related environmental (and social)
impacts have become an issue of worldwide relevance. There is an expectation that this trend will
continue in alignment with society’s increasing demand for raw materials. Yet the question remains:
how big is this issue?
To answer this question, the authors focus on four metals–iron, aluminium (i.e., bauxite ore),
copper, and gold. Iron, aluminium, and copper represent over 96 percent of all metals mined globally
Sustainability 2018,10, 2881; doi:10.3390/su10082881
Sustainability 2018,10, 2881 2 of 14
in terms of bulk tonnage [
], and together with gold they possess over 68% of industrial value [
In addition, the extraction technologies can be considered representative, making the results indicative
for metal mining as a whole. To evaluate environmental pressures, the authors focus on data for
three categories considered highly relevant to mining, admittedly by the industry itself (e.g., [
including climate change (i.e., CO
emissions), water use, and land use. To assess responses, the authors
look at the main providers of mining data, the United Nations (UN), government sources of some
main metal producing and consuming countries, the scientific literature, and company reports.
The main providers, i.e., US Geological Survey (USGS) [
], British Geological Survey [
], World
Mining Data (WMD) [
], and S&P [
], of mining data often do not include environmental data in their
publications. Their annual reports and S&P’s database focus on production and economic data only,
which, the authors would argue, means that aggregated environmental data are not yet considered as
material mining data for public disclosure.
The same can be said for UN and independent government sources: the International
Resource Panel (IRP) has produced various reports looking into the material flows of metals [
and their environmental impacts, including data for water consumption and greenhouse gas
emissions [16] (pp. 101–105)
—based on scientific literature further discussed below, but the IRP also
acknowledges that further research is required:
“Important knowledge is still missing in the linkages that exist between different types of
resources: metals, energy, water, and maybe others. This refers both to the resources needed
in the chain of the metals (e.g., energy for refining) and to the fact that metals are in some
cases mined as a by-product of other materials (mostly other metals, but sometimes other
materials, e.g. mercury production from natural gas). In scenario explorations for the future,
this is essential knowledge. It requires an interdisciplinary approach and the cooperation of
researchers from different fields to build up this type of knowledge.” [16] (p. 21).
The United States Geological Survey’s (USGS) webpage, makes reference to material flows and
that “understanding the whole system of material flow, from source to ultimate disposition, can help
us better manage the use of natural resources and protect the environment” [
], but none of the
studies listed include current or timely environmental data as described above. The European Union’s
Raw Material Information System (EU RMIS) also includes a section on environmental and social
sustainability, listing “water”, “air emissions and climate change”, and “land and biodiversity” as
areas, but they do not include specific environmental data required for meaningful analysis [
Other government websites, such as the Australian Bureau of Statistics [
], Natural Resources
Canada [
], the Chinese National Bureau of Statistics [
], or Statistics South Africa [
] all focus
on economic indicators such as production, sales, and gross value added or employment and not
environmental impact in our focus areas.
At the company level, in response to conflicts and increasing societal pressure, the majority of
mining companies have committed themselves to sustainability [
] and the reporting of environmental
data has become relevant, either through legal requirements such as the European Union’s (EU)
non-financial reporting directive [
], voluntary industry iniatives such as the International Council
for Mining & Metals’ (ICMM) requirement for its member companies to annually publish reports in
accordance with the Global Reporting Initiative (GRI) [
] or pressure from customers/consumers
and/or financiers for companies to respond to initiatives such as the CDP [
] or the Dow Jones
Sustainability Index [
]. However, such reporting is not mandated yet for all mining companies,
as it is either
not legally required or only required above a certain size, as is the case with [
] and
hence segmented environmental data is not consistenly available.
Given that data are not readily available on a commodity and/or mine site specific level from the
sources described above, the authors focus efforts on a review of scientific literature and company data
as described in Section 2, with the main aim to compile data on the environmental pressures brought
about by mining for four metals (iron, aluminium, copper, and gold), focusing on CO
Sustainability 2018,10, 2881 3 of 14
water use, and land use. For each metal, an estimated range (minimum, average, and maximum) for
the year 2016 and a comparison with company data is shown in Section 3. Section 4discusses the key
results and proposes a way forward.
2. Materials and Methods
The base of the data compilation is a literature review of existing scientific studies. In order
to check for the comparability of the data stemming from different sources and to select useful
publications a set of criteria is applied:
Boundary descriptions
The authors consider this as the main criterion. A data sample should include only production
sites at the same position in the value chain. Looking at mining, the production steps (i.e., mining,
concentration, purification, refining) are different depending on the metal in focus. Even for one
metal, processes applied at a site differ greatly, e.g., in copper production with pyro-metallurgical or
hydro-metallurgical routes [
] (p. 120), [
] (p. 24ff). Publications that separate process steps are rare,
because companies report for a production site and not for a production step. The majority of the
studies listed in Table 1consider the shipment of (concentrated) iron ore and bauxite from the mine
as the boundary. For copper and gold, the boundary includes purification and refining, but it does
not differ between underground or open pit mining and production routes. This study uses the same
definitions, but also presents estimates for downstream steel and aluminium production processes for
CO2and water use to allow for ‘mine to metal’ comparisons for all four metals.
Input parameter definitions
A clear definition of the parameters considered is needed. This is the case for CO
with the GHG
Protocol [
], but not for water data ([
]). In this study, we consider data for water withdrawal
and consumption.
Allocation method
In the case of companies/mines that produce more than one commodity; input/output
measurements alone do not provide enough information to attribute e.g., water consumption or
emissions to a single commodity. A description of the subsystems (processes) would be necessary.
To overcome this problem, volume flows are attributed to a commodity by allocation, e.g., based on
revenues achieved from the commodities [
] (p. 68). Reporting companies as well as authors of
publications should describe their allocation methods, otherwise they are not considered in this study.
Purpose of the publication
The purpose of the publication can influence the result because of sample bias, boundaries,
allocation method, input parameters, and other parameters connected to the intent. The result may be
good for a specific purpose, but may not be usable in the context of this study, which the authors check
against the first three criteria.
Table 1contains a basic description of the publications analyzed and if they were considered in
the analysis. It gives an overview of the purpose of the respective publication, the allocation method,
type of data, boundaries, if input parameter definitions exist and, based on these, our decision for
consideration and inclusion in the data summaries shown in the results section below.
Sustainability 2018,10, 2881 4 of 14
Table 1. Studies analysed for this paper.
Name Purpose Allocation Method Type of Data Boundary Definitions
Gold Mining in Australia: Linking
Historical Trends and Environmental
and Resource Sustainability [34]
Assess the development of
production and environmental data
of gold mining in Australia
None. By-products
not considered. Company reports
Au: Mine to Metal
Yes/Yes (scope
1)/-(not applicable) Yes (Water only)
Global Trends in Gold Mining:
Towards Quantifying Environmental
and Resource Sustainability [35]
Assess the sustainability of global
gold production in the context of
reporting, declining grades,
increasing efficiency, etc.
No information
provided Company reports Au: MtM Yes/unclear (?)/- Yes (Water only)
Sustainability Reporting and Water
Resources: a Preliminary
Assessment of Embodied Water and
Sustainable Mining [36]
The data have been grouped into
principal ore type to better assess the
effect on grade, scale, and sector
No information
provided Company data
Bauxite (B): Ore
Product (OP), Cu:
MtM, Au: MtM
Yes/-/- No (recycled
water is included)
Water Use in Metal Production:
A Life Cycle Perspective [37]
Estimate water consumption for
several commodities Unknown LCA B: OP, Cu: MtM,
Au: MtM ?/-/- No
Quantifying, Reducing, and
Improving Mine Water Use [33]
Estimate global water withdrawals
of the metals mining sector Economic Company data B: OP, Cu: MtM,
Au: MtM, Fe: OP Yes/-/- Yes
Energy and Greenhouse Gas Impacts
of Mining and Mineral Processing
Operations [38]
Assist the Australian minerals
industry in identifying potential
areas of improvement of their
environmental performance
None. All mines in
LCA produced only
one product
B: OP, Cu: Mine to
(MtC), Fe: MtC
Yes (not Cu due to
Using Life Cycle Assessment to
Evaluate Some Environmental
Impacts of Gold Production [39]
Compare refractory to
non-refractory ore. Identify impacts
of various production steps.
Mass and economic
for comparison LCA Au: MtM Yes/Yes/- Yes
Using Sustainability Reporting to
Assess the Environmental Footprint
of Copper Mining [28]
Show opportunities and limits of
reported data for creating
environmental footprints
Economic Company reports Cu: MtM Yes/Yes/- Yes
Assessing the Environmental Impact
of Metal Production Processes [40]Show various impacts
None. All mines in
LCA produced only
one product
LCA Cu: MtM -/Yes/- Yes
Good Practices and the Efficient Use
of Water in the Mining Industry [41]
Show the freshwater consumption of
Chilean copper mines. Compare
concentrators with hydro-metallurgy.
Show development
No information
provided Company data Cu: MtM Yes/-/- Yes
Sustainability 2018,10, 2881 5 of 14
Table 1. Cont.
Name Purpose Allocation Method Type of Data Boundary Definitions
Global Area Disturbed and
Pressures on Biodiversity by
Large-Scale Metal Mining [29]
Estimate the specific direct land use
for Au, Cu, Ag, Bauxite, and iron
ore mining
USGS satellite images
plus random sample
of mines
B: OP, Cu: MtC,
Au: MtC, Fe: MtC -/-/Yes
Yes (boundary
difference not
Unearthing the Carbon
Footprint [42]Unknown Unknown Value for base
metal ores
Comparable to
[38], but actually
-/?/- No
Quantifizierung der
Umwelteinwirkung des
Bauxitbergbaus [43]
Quantification of land use for
bauxite mining None Company data
and modelling B: OP -/-/Yes Yes
A Global Environmental Impact
Assessment for Bauxite
Mining—Land Use and Soil
Erosion [44]
Quantification of land use for
bauxite mining None Company data
and modelling B: OP -/-/Yes Yes
Flächeninanspruchnahme des
Kupferbergbaus [45]
Quantification of land use for
copper mining None Company data
and modelling Cu: MtC -/-/Yes
Yes (boundary
difference not
Entwicklung eines
Resourcenmanagementsystems [46]
Quantification of land use for
copper mining None Company data
and modelling Cu: MtC -/-/Yes
Yes (boundary
difference not
Sustainability 2018,10, 2881 6 of 14
For the calculations of the specific environmental pressures and the comparison of results,
this study applies the averages from the literature considered and also provides the minimum and
maximum numbers to show the range identified in the literature. Since the values are from different
years, the authors then update all pressures to 2016 by using the production data from WMD [
In the cases where no data on gross ore extraction but only data on net metal content are reported,
estimations were required, in order to transform all reported net metal content values into equivalents
of gross ores. For these estimations of ore grades, the data from the UN IRP Global Material Flows
Database [
] is used. In the evaluation, the assumption is that the average mined ore grade did
not change and that the specific environmental pressure (e.g., due to process changes or efficiency
gains) remained relatively constant. The authors are aware of the errors implied by these assumptions,
but data availability does not allow for a more accurate estimation.
For comparison, the environmental data publicly reported for 2016 by the top five mining
companies listed in Table 2, who represent between 19% and 68% of mine production for the four focus
metals, is analyzed. Since most of these companies produce multiple commodities and do not report
their data broken down to the commodity level (in some cases the organization of companies is based
on commodity and therefore the data might be reported), an additional survey is used to ask for their
commodity specific data. Finally, the authors extrapolate these data, based on production share, to the
overall 2016 production of each metal, allowing for an approximate comparison of the results from
literature with actual data reported by companies.
Table 2. List of companies and their share of production for each commodity.
Copper (2016) Units Gold (2016) Units
Codelco 1.827 Mt Barrick 5.52 Moz
1.696 Mt Newmont 4.9 Moz
Glencore 1.288 Mt Anglo Gold Ashanti 3.63 Moz
BHP 1.113 Mt Goldcorp 2.87 Moz
Southern Copper 0.9 Mt Kinross 2.79 Moz
Share of WMD 33.4 % Share of WMD 19.1 %
Bauxite (2015) Units Iron ore (2015) Units
Rio Tinto 44 Mt Vale 345.9 Mt
Alcoa 38 Mt Rio Tinto 327.6 Mt
Chalco 18 Mt BHP 227 Mt
CBG 15.2 Mt FMG 169.4 Mt
Hydro 10.1 Mt
Share of WMD 43.2 % Share of WMD 68.0 %
Sources:; gold-producers/;
detail/26315/top-five-bauxite-mining- companies-in- the-world;
ore-producers-h1- 2016/; Company reports, WMD [7]; all links accessed 12 June 2018.
3. Results
Overall, the authors find 16 publications of which 13 are considered in this study, which means
that the number of publications investigating the environmental pressures of mining for iron, bauxite,
copper, and gold is limited to between one and five per commodity.
The variation in the results from the different publications is within a factor of three for the
specific environmental pressure of a commodity, even after considering the selection criteria. In some
cases, the variation of data for mine sites can be within a factor of 100, as in [
], with a range of
9.8 to
1046.9 m3/t
Cu of water consumption. This is due to different mine types and processing routes.
The detailed results for CO2, water, and land are described below.
The company survey the authors wanted to use to get more reliable data for comparison had a
very poor response rate. Of the companies listed in Table 2, only one—Rio Tinto—sent back data as
requested. Four companies said that they do not disclose any additional data other than what they
Sustainability 2018,10, 2881 7 of 14
disclose in company reports or to initiatives such as the CDP or sustainability rating organizations
and the remaining companies did not respond at all. Therefore, the comparison of company data with
literature data is very limited, and we are only able to compare specific factors rather than overall
values for 2016. Given these limitations, the numbers are shown below, but the results are not discussed
any further since they show some large variations, which might be explained by variations in the
selection criteria listed above and which are not analysed at this stage, given the very limited company
data. We also do not show the company names in the tables.
3.1. CO2Emissions
Literature on CO
emissions is closely linked to literature on energy consumption. Declining ore
grades and the increasing geologic and metallurgical complexity of orebodies are leading to increased
energy demands [
] (p. 266), that might ultimately be offset by the development of more energy
efficient technology [
] (p. 2). Reporting methods/definitions [
], [
], emission factors [
] (p. 125),
allocation methods, and the minor significance compared to the downstream processes (i.e., aluminium
or steel making) [38] (p. 266) are further key factors in this discussion.
Table 3shows the literature data for all four commodities. Estimations for CO
emissions of
copper and gold show a similar variation to water below. It is notable that all values from life cycle
analysis are higher than results from studies based on company reports. Tables 4and 5show the
data (average of studies, minimum and maximum) updated to 2016 and the available company data
for comparison.
The estimations in Table 4show that copper and gold (with both calculation routes delivering
similar results) cause the highest emissions, followed by iron ore and bauxite, which causes by far the
lowest emissions of the four commodities.
The authors estimate that the average of the literature values updated to 2016 is 190.5 Mt of CO
emissions for the mining of bauxite, copper, gold, and iron ore based on commodity produced. For ore
based values combined with the global ore processed, the result is very similar at 189.8 Mt respectively.
The minimum and maximum values from literature lead to a range of 149.6 Mt to 233 Mt.
Table 3.
Summary of literature values for CO
emissions of bauxite, copper, gold, and iron ore mining.
Max. Min. Average Units Source
Ore 4.9 kg CO2/t [38]
8.5 0.9 2.6 kg CO2/kg [28]
3.3 kg CO2/kg [40]
6.2 kg CO2/kg [40]
Ore 61.7 kg CO2/t [39]
77.2 kg CO2/t [39]
26,840 kg CO2/kg [39]
17,560 kg CO2/kg [39]
19,520 kg CO2/kg [39]
29,820 kg CO2/kg [39]
Iron Ore
Ore 11.9 kg CO2/t [38]
Sustainability 2018,10, 2881 8 of 14
Table 4. Global CO2emissions of bauxite, copper, gold, and iron ore mining in 2016.
Result of the Literature Review CO2emissions 2016 [Mt]
Ore Average 4.9 kg CO2/t 1.4
Average 3.7 kg CO2/kg 75
Max. 4.8 kg CO2/kg 97
Min. 2.6 kg CO2/kg 53
Average 69.5 kg CO2/t 74.6
Max. 77.2 kg CO2/t 82.9
Min. 61.7 kg CO2/t 66.3
Average 23,435 kg CO2/kg 75.3
Max. 29,820 kg CO2/kg 95.8
Min. 17,560 kg CO2/kg 56.4
Iron Ore
Ore Average 11.9 kg CO2/t 38.8
Table 5. CO2data from company sustainability reports and comparison to literature average values.
Commodity Specific CO2Emissions Units Average of Literature Values
Bauxite 10 kg CO2/t 4.9
Copper 2.46 kg CO2/kg Cu 3.7
Copper 8.8 kg CO2/kg Cu
Gold 23,300 kg CO2/kg Au 23,435
Iron Ore 10.39 kg CO2/t
Iron Ore 9.3 kg CO2/t
Iron Ore 13 kg CO2/t
Global CO
emissions from fossil fuels and industry for 2016 are estimated at about 36 Gt [
which means that the mining of bauxite, copper, gold, and iron ore contributes approximately between
0.4 and 0.7 percent to these CO
emissions. Considering only fossil fuel combustion, the International
Energy Agency (IEA) estimates CO
emissions at 32 Gt [
], of which 36 percent can be attributed to
industry (p. 12). Using this as a baseline, mining of these four metals contributes between 1.3 and
2 percent of all industrial emissions.
The picture changes completely in consideration of the downstream, highly energy intensive
processes for iron ore/steel and bauxite/aluminium, where emissions for 2016 were about 3.1 Gt [
(p. 4) and 1 Gt [54].
3.2. Water Withdrawals
Based on the reasons discussed above, i.e., different definitions regarding water withdrawals
and consumption, the literature does not show as much coherence about mine water use as would be
desirable. Gunson [
] is the most comprehensive publication dealing with water withdrawals of the
mining industry and he describes this problem of coherence much in the same way.
Table 6shows the literature data for all four commodities. For bauxite and iron ore, little data is
available. For copper production, some publications distinguish pyro-metallurgical production from
concentrate and hydro-metallurgical production without previous concentration. The publications
show that hydro-metallurgical production consumes significantly less water. Tables 7and 8show the
Sustainability 2018,10, 2881 9 of 14
data (average of studies, minimum and maximum) updated to 2016 and the available company data
for comparison.
Table 6. Summary of literature values for water use of bauxite, copper, gold, and iron ore mining.
Max Min Average Units Source
Ore 1.154 0.022 0.404 m3/t [33]
3.065 0 0.521 m3/t [33]
0.432 0.1 0.22 m3/t [33]
1.4 0.92 1.16 m3/t [41]
1046.9 9.8 70.4 m3/t [28]
402.61 0.013 88.03 m3/t [33]
96.18 27.77 48.01 m3/t [33]
1.72 0.67 0.88 m3/t [34]
2.87 0.72 1.42 m3/t [35]
10.9 0.003 0.745 m3/t [33]
666,000 224,000 325,000 m3/t [34]
1,783,000 224,000 691,000 m3/t [35]
259,290 m3/t [39]
288,140 m3/t [39]
4,742,000 610 400,000 m3/t [33]
Iron Ore
Ore 3 0.094 0.598 m3/t [33]
Table 7. Global water withdrawals of bauxite, copper, gold, and iron ore mining in 2016.
Result of the Literature Review Withdrawals 2016 (Mm3)
Ore Average 0.404 m3/t 115
Average 0.765 m3/t 1730
Max. 1.16 m3/t 2630
Min. 0.371 m3/t 840
Average 69.21 m3/t 1413
Max. 70.4 m3/t 1440
Min. 68.02 m3/t 1389
Average 1.015 m3/t 1090
Max. 1.42 m3/t 1530
Min. 0.745 m3/t 800
Average 422,428.75 m3/t 1358
Max. 691,000 m3/t 2221
Min. 273,715 m3/t 880
Iron Ore
Ore Average 0.598 m3/t 1950
Sustainability 2018,10, 2881 10 of 14
Table 8.
Water data from company sustainability reports and comparison to literature average values.
Commodity Specific Withdrawals Units Average of Literature Values
Bauxite 0.604 m3/t 0.404
Copper 245 m3/t 69.21
Gold 0.379 m3/t 1.015
Iron Ore 1.047 m3/t 0.598
Iron Ore 1.410 m3/t
As Table 7shows, iron ore causes the largest water withdrawals, followed by copper and
gold (with some variation in the calculation routes) and once again bauxite with the lowest
water withdrawals.
The sum of the global water withdrawals we estimated from the minimum and maximum values
from literature for bauxite, copper, gold, and iron ore mining in 2016 is between 3705 and 6225 Mm
with an average of about 4850 Mm3.
To put these numbers into a global context: The Food and Agriculture Organization of the United
Nations (FAO) estimates the global water withdrawal for 2010 as almost 4000 Gm
, with industrial
withdrawals accounting for about 19 percent [
]. Assuming the same growth rate as in the years
1900–2010 of about 31 Gm
per year for the years 2010–2016, bauxite, copper, gold, and iron ore
mining is in a range of 0.09 and 0.15 percent of global water withdrawals and 0.46 and 0.78 percent of
industrial withdrawals.
Same as for CO
emissions, this changes significantly if downstream water withdrawals for
steelmaking (estimated at 45.8 Gm
based on [
] (p. 4)) and aluminium production (estimated at
1.3 Gm3based on [54] (appendix A)) are considered.
3.3. Land Use
According to S&P Global Market Intelligence there are over 36,000 mining properties in the world [
Estimates for the global area disturbed by mining range from 0.3 [
] to 1 [
] percent of terrestrial land
surface. The estimations have in common that they are vague. Either the basis for the estimation is unclear
as in the case of Norse et al. [
], suggesting a global area disturbed by mining of 0.5 to 1.0 Mkm
, or data
was only available for some countries and the global estimate is an extrapolation [57].
A key publication on the subject is by Murguia [
], who based his study on mine sites visible on
satellite images. Table 9shows the specific values from literature for land use for each commodity analyzed
in this paper. The data is complemented by older studies on direct land use for copper and bauxite.
Table 9. Summary of literature values for land use of bauxite, copper, gold, and iron ore mining.
Max Min Average Units Source
7.98 ha/Mt [29]
21 ha/Mt [43]
13 ha/Mt [44]
16 ha/Mt
International Aluminium Institute, 2009, cited in [
4.5 ha/Mt [29]
2.3 ha/Mt [45]
2 ha/Mt [46]
Ore Max Min Average Units Source
6.7 ha/Mt [29]
Iron Ore
Ore Max Min Average Units Source
4.25 ha/Mt [29]
Sustainability 2018,10, 2881 11 of 14
Tables 10 and 11 show the data (average of studies, minimum and maximum) updated to 2016
and the available company data for comparison.
Table 10. Newly disturbed global land use for bauxite, copper, gold, and iron ore mining in 2016.
Result of the Literature Review Land Use 2016 (km2)
Average 14.5 ha/Mt 41.3
Max. 21.0 ha/Mt 59.8
Min. 7.98 ha/Mt 22.7
Average 2.9 ha/Mt 66
Max. 4.5 ha/Mt 100
Min. 2 ha/Mt 45
Ore Average 6.7 ha/Mt 72
Iron Ore
Ore Average 4.25 ha/Mt 139
Table 11.
Land data from company sustainability reports and comparison to literature average values.
Commodity Specific Land Use Units Average of Literature Values
Bauxite 23 ha/Mt
Bauxite 33.2 ha/Mt
Bauxite 107.6 ha/Mt
Iron Ore 11.86 ha/Mt 4.25
To sum up, 318 km
have been newly disturbed by mining of bauxite, copper, gold, and iron ore
in 2016 using the average values from literature, with a range of 278 km
to 370 km
using minimum
and maximum values. Since the area is very small, we did not put this in a global context.
Murguia also calculated the cumulative net area disturbed for these four commodities in 2011
as 11,485 km
] (p. 163) and looked into the types of land disturbed as a proxy for the impact
on biodiversity.
4. Discussion
In this paper, the authors analysed three categories of environmental pressures—CO
water use, and land use—related to global mining of bauxite, copper, iron ore, and gold-making results
indicative for metal mining. The available numbers show that in absolute terms and on the global
level the overall dimension of the pressures put on the environment—about 190 Mt of CO
4850 Mm
of water use and 318 km
of newly disturbed land in 2016—are comparably low However,
this must not be seen as a charter to not taking mining activities into environmental considerations.
These remain relevant, especially as the local impacts are increasing, and will do so even more in the
future, as demand for metals increases and accessibility declines. These numbers change of course
significantly for CO
emissions and water use in the case of iron ore and bauxite when including the
production of steel and aluminium in the analysis.
The data review reveal that, to carry out such environmental analyses, available data are still
very limited, and there are significant gaps in comparability of different sources, especially related
to the identified boundary conditions (including type of mine and process routes), input parameter
definitions, and the applied allocation methodology. Hence, further work is needed to align these
assessments with the identified criteria. Another key limitation is the lack of detailed reporting of
Sustainability 2018,10, 2881 12 of 14
environmental data at the company level, a concern which Mudd [
] and Northey et al. [
] raised in
their studies and which has not changed since. Similar to (economic) production data, where this is
largely already the case, environmental data would need to be reported consistently, at the commodity
and at the site, ideally even process, level. This would allow for further comparison of process routes
and technologies, but also for better modelling of future environmental pressures from increased metal
demand, as well as better policy making related to metal mining, for example in areas such as mining’s
role in achieving the Sustainable Development Goals (SDGs), the circular economy, responsible supply
chain management, and trade agreements or the transition of our energy system towards a low
carbon footprint.
Suggesting a way forward to overcome these limitations, organizations like GRI, ICMM, and the
commodity specific associations should collaborate to define (and standardize) the criteria mentioned
above and update standards for companies to report at the site level. Data providers such as WMD,
USGS, or S&P should then think about broadening their services to include environmental (and social)
data in their products.
Author Contributions:
Conceptualization, M.T.; Methodology, M.T. and B.B.; Validation, M.H., S.L., and P.M.;
Formal Analysis, B.B., M.T., and S.L.; Investigation, B.B. and M.T.; Writing—Original Draft Preparation, M.T.;
Writing—Review & Editing, M.H., S.L., and S.F.; Supervision, M.H. and P.M.
Funding: This research received no external funding.
The authors would like to acknowledge the cooperation and assistance of Diego Murguia and
Aaron Gunson concerning questions about their studies and would like to express appreciation to the anonymous
reviewers, who helped to improve this paper.
Conflicts of Interest: The authors declare no conflict of interest.
1. Niavis, P. Iudicium Iovis in Valle Amoenitatis; Martin Landsberg: Leibzig, Germany, 1492.
2. Agricola, G. Zwölf Bücher vom Berg-und Hüttenwesen; Froben: Basel, Switzerland, 1556.
3. Von Carlowitz, H.C. Sylvicultura Oeconomica; Johann Friedrich Braun: Freiberg, Germany, 1713.
Steffen, W.; Broadgate, W.; Deutsc, H.L.; Gaffney, O.; Ludwig, C. The trajectory of the Anthropocene:
The Great Acceleration. Anthropocene Rev. 2015,2, 81–98. [CrossRef]
Moser, P. Raw materials as re-industrialization opportunities. Presented at REinEU Conference, Bratislava,
Slovakia, 26–28 October 2016.
6. International Resource Panel (IRP). Assessing Global Resource Use; UNEP: Paris, France, 2017.
Reichl, C.; Schatz, M.; Zsak, G. World Mining Data; Federal Ministry for Sustainability and Tourism: Vienna,
Austria, 2018. Available online:
-_2018_new%21 (accessed on 11 June 2018).
8. Ericsson, M.; Hodge, A. Trends in the Mining and Metals Industry; ICMM: London, UK, 2012.
Odell, S.; Bebbington, A.; Frey, K. Mining and climate change: A review and framework for analysis.
Extract. Ind. Soc. 2018,5, 201–214. [CrossRef]
Franks, D. Mountain Movers, Mining, Sustainability and the Agents of Change; Routledge: Abingdon, UK, 2015.
ICMM. Environment. 2018. Available online: (accessed on
7 June 2018).
Anglo American. Environment. 2018. Available online:
environment (accessed on 7 June 2018).
USGS. Minerals Yearbook; USGS: Reston, VA, USA, 2016. Available online:
minerals/pubs/myb.html (accessed on 20 June 2018).
British Geological Survey. World Mineral Production 2012–2016; BGS: Nottingham, UK, 2017; Available online: (accessed on 20 June 2018).
S & P Global Market Intelligence. Essential Mining Industry Data with Actionable Insights. 2018. Available
online: mining (accessed on
5 June 2018).
Sustainability 2018,10, 2881 13 of 14
United Nations Environment Programme. Environmental Risks and Challenges of Anthropogenic Metals Flows
and Cycles, A Report of the Working Group on the Global Metal Flows to the International Resource Panel; UNEP:
Paris, France, 2013.
USGS. Materials Flow; US Geological Survey: Reston, VA, USA, 29 May 2018. Available online: https:
// (accessed on 4 June 2018).
European Commission. Raw Material Information System (RMIS). 2018. Available online: (accessed on 7 June 2018).
Australian Bureau of Statistics. Browse Statistics. 2016. Available online:
opendocument&ref=topBar (accessed on 7 June 2018).
Natural Resources Canada. Mining & Minerals; Natural Resources Canada: Ottawa, ON, Canada, 2018.
Available online: thematic-
maps/16878 (accessed on 7 June 2018).
National Bureau of Statistics of China. National Data. 2018. Available online:
english/easyquery.htm?cn=B01 (accessed on 7 June 2018).
Statistics South Africa. Category Archives: Minerals. 2018. Available online:
?cat=41 (accessed on 7 June 2018).
Tost, M.; Hitch, M.; Chandurkar, V.; Moser, P.; Feiel, S. The state of environmental sustainability
considerations in mining. J. Clean. Prod. 2018,182, 969–977. [CrossRef]
European Commission. Non-Financial Reporting. 2018. Available online:
en (accessed on 4 June 2018).
ICMM. Member Reporting and Performance. 2018. Available online:
members/member-reporting-and- performance (accessed on 4 June 2018).
CDP. CDP—Disclosure, Insight, Action; CDP: London, UK, 2018; Available online:
(accessed on 25 June 2018).
RobecoSAM. DJSI Annual Review 2017. 2018. Available online:
sustainability-insights/about-sustainability/corporate-sustainability-assessment/review.jsp (accessed on
25 June 2018).
Northey, S.; Haque, N.; Mudd, G. Using sustainability reporting to assess the environmental footprint of
copper mining. J. Clean. Prod. 2013,40, 118–128. [CrossRef]
Murguia, D. Global Area Disturbed and Pressures on Biodiversity by Large Sclae Metal Mining; Kassel University
Press: Kassel, Germany, 2015.
World Business Council for Sustainable Development (WBCSD). The GHG Protocol: A Corporate Reporting
and Accounting Standard. 2018. Available online:
Resources/A-corporate-reporting-and-accounting-standard (accessed on 6 June 2018).
Organisation for Economic Co-operation and Development (OECD). Water Withdrawals. 2018. Available
online: (accessed on 6 June 2018).
World Resources Institute. What’s the Difference between Water Use and Water Consumption?
12 March 2013
. Available online:
between-water-use-and-water-consumption (accessed on 6 June 2018).
Gunson, A.J. Quantifying, Reducing and Improving Mine Water; University of British Columbia: Vancouver,
BC, Canada, 2013.
Mudd, G. Gold mining in Australia: Linking historical trends and environmental and resource sustainability.
Environ. Sci. Policy 2007,10, 629–644. [CrossRef]
Mudd, G. Global trends in gold mining: Towards quantifying environmental and resource sustainability.
Resour. Policy 2007,32, 42–56. [CrossRef]
Mudd, G. Sustainability Reporting and Water Resources: A Preliminary Assessment of Embodies Water and
Sustainable Mining. Mine Water Environ. 2008,27, 136–144. [CrossRef]
Norgate, T.; Lovel, R. Water Use in Metal Production: A Life Cycle Perspective; CSIRO: Canberra,
Australia, 2004.
Norgate, T.; Haque, N. Energy and greenhouse gas impacts of mining and mineral processing operations.
J. Clean. Prod. 2010,18, 266–274. [CrossRef]
Norgate, T.; Haque, N. Using life cycle assessment to evaluate some environmental impacts of gold
production. J. Clean. Prod. 2012,29–30, 53–63. [CrossRef]
Sustainability 2018,10, 2881 14 of 14
Norgate, T.; Jahanshahi, S.; Rankin, W. Assessing the environmental impact of metal production processes.
J. Clean. Prod. 2007,15, 838–848. [CrossRef]
Cochilco. Good Practices and the Efficient Use of Water in the Mining Industry; Cochilco, Santiago,
Chile, 2008.
42. Labriola, A. Unearthing the carbon footprint. Aust. Min. 2009,101, 34–35.
Sliwka, P. Quantifizierung der Umweltauswirkungen des Bauxitbergbaus unter besonderer Berücksichtigung
der Flächeninanspruchnahme. Mitteilungen zur Inginneugeologie und Hydrogeologie 2001,78, 1–170.
Sliwka, P.; Bauer, C.; Eden, K.; Grassmann, J.; Mistry, M.; Röhrlich, M.; Ruhrberg, M.; Sievers, H. A Global
Environmental Impact Assessment for Bauxite Mining—Land Use and Soil Erosion; RWTH Aachen: Aachen,
Germany, 2001.
Martens, P.; Ruhrberg, M.; Mistry, M. Flächeninanspruchnahme des Kupferbergbaus. Erzmetall
55, 287–293.
Ruhrberg, M. Entwicklung Eines Betriebsübergreifenden Resourcenmanagementsystems für Metallische Rohstoffe am
Beispiel des Kupferbergbaus; RWTH Aachen: Aachen, Germany, 2002.
International Resource Panel (IRP). Technical Annex for Global Material Flows Database; UN International
Resource Panel: Paris, France, 2018; Available online:
Material-Flows_db/Technical-annex-for-Global-Material-Flows-Database.pdf (accessed on 8 June 2018).
Nuss, P.; Eckelman, M. Life cycle assessment of metals: A scientific synthesis. PLoS ONE
,9, e101298.
[CrossRef] [PubMed]
GRI. GRI Standards. 2018. Available online: (accessed on
8 June 2018).
Global Carbon Atlas. Emissions. 2018. Available online:
emissions (accessed on 17 June 2018).
PBL Netherlands Environmental Assessment Agency. Trends in Global CO2 and Total Greenhouse Gas
Emissions: 2017 Report. 2017. Available online:
pbl-2017-trends-in-global-co2-and-total-greenhouse-gas-emissons-2017- report_2674.pdf (accessed on
8 June 2018).
IEA. CO2 Emissions from Fuel Combustion 2017. 2017. Available online:
emissions-from-fuel-combustion-overview-2017 (accessed on 17 June 2018).
World Steel Association. Sustainable Steel, Indicators 2017 and the Future. 2017. Available
update0408.pdf (accessed on 20 June 2018).
World Aluminium. 2015 Life Cycle Inventory Data and Environmental Metrics. June 2017. Available
june_2017.pdf (accessed on 20 June 2018).
Food and Agriculture Organization of the United Nations. Did you Know
. . .
? Facts and Figures about.
December 2014. Available online:
(accessed on 18 June 2018).
World Steel Association. Water Management in the Steel Industry; World Steel Association: Brussels,
Belgium, 2015.
Hooke, R.; Martín-Duque, J.F. Land transformation by humans: A review. GSA Today
,12, 4–10.
Bridge, G. Contested Terrain: Mining and the Environment. Annu. Rev. Environ. Resour.
,29, 205–259.
Norse, D.; James, C.; Skinner, B.; Zhao, Q. Agriculture, land use and degradation. In An Agenda of Science
for Environment and Development into the 21st Century; Cambridge University Press: Cambridge, UK, 1992;
pp. 79–89.
2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (
... Eine der planetaren Grenzen ist der Süßwasserverbrauch, der im Bergbau eine wesentliche Rolle spielt, da oft große Mengen an Wasser benötigt werden [20,21]. Integrierte, auf Wassereinzugsgebieten basierende Wasserbewirtschaftung bedeutet eine umfassende und von allen Interessenshalter*innen gemeinsam geplante Vorgangsweise, bei der Gewässer als wertvolle Ressourcen gesehen werden und Wasserqualität, -effizienz und die Vermeidung von Wasserverbrauch im Vordergrund stehen. ...
... Auf diese Weise kann eine flexible, widerstandsfähige Wasserinfrastruktur geschaffen werden, die auf verschiedenste Szenarien, v. a. hinsichtlich Klimawandel, reagieren kann. Auch sind die Gewinnung und Verarbeitung von mineralischen Rohstoffen energieintensiv und daher gegenwärtig mit hohen CO2 Emissionen verbunden [21]. Mit dem Ziel der CO2-Neutralität [22] muss der Energieverbrauch überwiegend auf erneuerbaren Energien beruhen. ...
Zusammenfassung Nachhaltigkeit und nachhaltige Entwicklung sind komplexe Themen. Die Gewinnung mineralischer Rohstoffe nimmt dabei aufgrund des ökonomischen Potentials und der Umwelt- und Sozialauswirkungen eine wesentliche Rolle ein. Daher wäre ein einheitlicher Rahmen zur Beschreibung einer verantwortungsvollen bzw. nachhaltigen Rohstoffgewinnung in Europa von Vorteil. Teil des Horizon 2020 Projektes SUMEX ist die Schaffung solch eines Rahmens. Das Projekt untersucht die Transformation des europäischen Rohstoffsektors von der Einhaltung bestehender Gesetze und einem verantwortungsvollen Umgang hin zu nachhaltigem Management. Mittels Recherche existierender Definitionen und Strategien zur Nachhaltigkeit im Kontext der Gewinnung mineralischer Rohstoffe, sowie Interviews mit verschiedenen Stakeholdern, wurde der SUMEX Nachhaltigkeitsansatz entwickelt. Dieser wurde speziell auf die europäische Rohstoffgewinnung zugeschnitten und soll dabei helfen, die erforderliche Transformation zu einem nachhaltigen Sektor bis zum Jahr 2050 zu verwirklichen. Der SUMEX Nachhaltigkeitsansatz beschreibt Aspekte eines nachhaltigen Managements in der europäischen Rohstoffindustrie durch verschiedene Themen und Ziele.
... The average increased to 13,900 kg CO 2 -e/kg gold when the period was extended two years from 1991 to 2008 (Mudd, 2010). Tost et al. (2018) analysed the GHG emissions of the five largest gold producers in 2016, representing 19.7 Moz or 19% of world gold production, determining an average GHG emissions intensity of 23,300 kg CO 2 -e/kg gold. The World Gold Council (2019a) estimate the total GHG emissions footprint for the total gold market to be 126.4 ...
... The weighted average GHG emission intensity of the studied mines was 726 kg CO 2 -e/oz (23,300 kg CO 2 -e/kg), which is an increase of 68% on the 13,900 kg CO 2 -e/kg observed by Mudd (2010). It is the same as the average of the five largest gold companies in 2016 observed by Tost et al. (2018). This study is lower than the GHG emissions intensity of the World Gold Council (2019a) estimate for 2018 Scopes 1 and 2 emissions calculated to be 892 kg CO 2 -e/oz (28,700 kg CO 2 -e/kg). ...
Full-text available
Global greenhouse gas (GHG) emissions from gold mining exceed 100 Mt CO2-e annually, with country emissions intensity from 129 to 2754 kg CO2-e/oz, yet clear knowledge gaps remain regarding country contributions, emissions reduction potential, and impact of carbon pricing. The cost impacts upon global gold miners of the introduction of a hypothetical US$50/t CO2-e and US$100/t CO2-e carbon price are quantified and are affordable. Carbon price impacts vary markedly between countries, with a US$100/t CO2-e price increasing gold production costs on average by US$13 per ounce in Finland and up to US$275/oz in South Africa. The research method aggregated 2018 mine-specific GHG emission and production data to the country level, allowing carbon price impacts to be quantified. Global adoption of carbon pricing changes the relative cost competitiveness of countries, having policy implications. Clean energy substitution and energy efficiencies, including new mining technologies, are at the forefront of the gold sector responses to reduce emissions. The reduction in GHG emissions from energy substitution of the mine's primary energy source is up to 46%. The most significant reductions in GHG emissions from energy efficiencies are in underground mines from ventilation and cooling, up to 24%. Gold companies that reduce their carbon footprint benefit from a lower cost of capital. Clear potential exists for a shift towards a cleaner, decarbonised global gold industry.
... Additionally, some studies are based on individual mine-site surveys, while others cover a wide range of mine-site specific data derived from mining companies' sustainability reports. Moreover, the challenge of the lacking coherence of mine water use in the literature and LCA databases is described in almost every study conducted, such the studies of Gunson (2013) [93]. As a consequence, the comparison of data within the literature is very limited [97], particularly between all commodities observed. ...
... [27],Northey et al. (2016) [14] andTost et al. (2018) ...
Full-text available
The consumption of freshwater in mining accounts for only a small proportion of the total water use at global and even national scales. However, at regional and local scales, mining may result in significant impacts on freshwater resources, particularly when water consumption surpasses the carrying capacities defined by the amount of available water and also considering environmental water requirements. By applying a geographic information system (GIS), a comprehensive water footprint accounting and water scarcity assessment of bauxite, cobalt, copper, iron, lead, manganese, molybdenum, nickel, uranium and zinc as well as gold, palladium, platinum and silver was conducted to quantify the influence of mining and refining of metal production on regional water availability and water stress. The observation includes the water consumption and impacts on water stress of almost 2800 mining operations at different production stages, e.g., preprocessed ore, concentrate and refined metal. Based on a brief study of mining activities in 147 major river basins, it can be indicated that mining’s contribution to regional water stress varies significantly in each basin. While in most regions mining predominantly results in very low water stress, not surpassing 0.1% of the basins’ available water, there are also exceptional cases where the natural water availability is completely exceeded by the freshwater consumption of the mining sector during the entire year. Thus, this GIS-based approach provides precise information to deepen the understanding of the global mining industry’s influence on regional carrying capacities and water stress.
... According to [3], up to 0.674 x 10 6 m 3 of water is used during the mining and beneficiation of 1 ton PGMs, of which 0.272 x 10 6 m 3 is actually consumed while the remainder is recycled. This consumption rate is markedly higher than even the upper extreme of the benchmark ranges of 0.252 x 10 6 m 3 ·ton -1 to 0.379 x 10 6 m 3 ·ton -1 for gold processing given by [4,5]. In addition to this problem of a high water consumption rate, mining also causes pollution of water bodies through effluent discharge and gangue seepage [6,7,8]. ...
Full-text available
The mining industry is faced with a double challenge of diminishing water availability and deteriorating water quality, with high mine effluent discharges exacerbating the latter. Mining companies must adopt effective ways to make their water service networks sustainable, simultaneously addressing problems of high water consumption and high pollution load, while ensuring that enough water is provided at the right quality for various processes. This papers aims to examine the water network for a PGM mining and beneficiation operation, in order to identify major drivers of poor water quality and high water usage, as well as to give direction for process optimisation. The study first considers the mining and beneficiation process steps, establishing the value-chains for both mineral and water. It then takes an LCA methodological approach to define each process step, identifying the variables that influence pollution load. Relevant process factors are extracted from literature and incorporated into a causal loop diagram. A stock and flow dynamic model is developed, with source, sink and flow rates of water clearly defined. The resulting system is simulated using modelling software and optimised for the following objectives: maximised mineral yield, maximised reused water, minimised freshwater extraction, discharged wastewater and treated water for reuse. Based on results, biggest factors influencing pollution load are identified and strategies for improving water efficiency are discussed. The extent to which water recycling offsets demand for freshwater extraction is determined, together with its impact on effluent discharge. Finally, challenges to be addressed in future research work are discussed. Unlike previous studies that mostly focussed on optimising water use for a single process, usually floatation, this study took a holistic approach and considered the entire value chain of mining and beneficiation.
... Millions of people in developing countries depend on artisanal and small-scale gold mining (ASGM) for their livelihoods. However, this activity comes at a price [3,4]. These activities are quite diverse, sometimes illegal or informal, often virtually tolerated by the authorities, and can be seasonal or year-round, long-term, or follow a boom-and-bust cycle. ...
Full-text available
Artisanal and small-scale gold mining (ASGM) and large-scale mining in the Ecuadorian Amazon region is potentially harmful to nature, and its impacts are associated with environmental degradation and deterioration of people's health. So far, limited efforts have been directed at exploring the current situation and challenges facing the implementation of environmental policies in the country. The objective of this study focused on analyzing the historical and current situation and challenges of ASGM in the Amazon region of Ecuador in relation to a political perspective (laws), socioeconomic impacts (population displacement, loss of livelihoods, migration of people, cost of living, water scarcity, and health impacts), and environmental impacts (biotic and abiotic). The methodology used was based on a literature review and interviews, and information that was discussed through an expert judgment allowed for establishing challenges to improve ASGM management. The main results indicate that lack of community participation in decision-making, insufficient coordination between government institutions, communities, and miners, and lack of control of mining activities are factors that contribute to ineffective compliance with environmental policies in the gold mining sector in the Amazon. Finally, the study concludes by considering the socioeconomic and environmental scopes within its findings for implementing effective environmental and social policies in the Amazon region of Ecuador.
... No hard rock operational data was found. Land disturbed in HMS mining is higher than that seen for copper extraction at 2-4.5 ha/MT of ore, and comparable to iron ore at 4.25 ha/Mt ore but was significantly lower than bauxite which requires 7.98-21 ha/Mt ore (Tost et al., 2018). No correlation between land disturbed and mined grades were found; this is likely because the land disturbed during any one year does not necessarily correspond to ore mining (i.e. ...
The growing focus on environmental responsibility from the community, investors and regulators presents immense challenges and opportunities to mining companies. Titanium and zirconium minerals are vital, unrecyclable, and often irreplaceable components of modern infrastructure and technology. The companies which supply these minerals often have a long-history of sustainability reporting. Such reports have been used here to analyse energy usage, carbon dioxide emissions and water usage from mining and processing these minerals. Mining operations and titanium-slag producers in Australia, Canada, China, Mozambique, Madagascar, Norway, and South Africa were analysed. This paper presents both site-specific data as well as data generalized to heavy mineral sand (HMS) deposits vs igneous hard-rock style deposits, as well as those products which have undergone beneficiation. In terms of averages, energy use was higher for HMS (yearly average of between 0.90 – 2.95 GJ/t valuable heavy mineral (VHM)) compared to ilmenite-dominant hard-rock mining (yearly average of between 0.21 – 0.49 GJ/t ilmenite) and Ti-slag production required between ∼10 – 14 GJ/t of saleable product (including titanium slag and pig-iron). Emissions from ilmenite-dominant hard rock mining produced ∼0.01 t CO2e/t ilmenite concentrate while HMS mining produced 0.07-0.38 t CO2e/t of VHM; emissions from beneficiating ilmenite into Ti-slag add significantly to this (0.62-1.21 t CO2e/t of saleable product, weighted by value). Overall, hard-rock mining operations consumed <5 kL/t ilmenite concentrate while HMS consumed 10-26 kL/t VHM. On the other hand, beneficiating hard-rock ilmenite into slag increases water-use by ∼220 kL/t of saleable product. Finally, in terms of land use, it was determined that an average of 4.3 ha per 1 Mt of ore was disturbed in HMS operations (no data was available for hard-rock operations). While average results comparing HMS, hard-rock and beneficiated products were broadly comparable to existing LCA literature, data used in LCA literature is not consistent with specific sites and using generalized data to infer site-specific data will often lead to erroneous estimates. These observations taken together are particularly important to downstream purchasers, as well as the investment community who do not fund entire industries, but fund and back specific projects; the decision made on which site or company to invest in is increasingly determined by environmental, social and governance (ESG) related factors. This paper not only provides quantitative indications of these factors for Ti/Zr production, but also guidance for improving sustainability reporting in the industry. An improvement in the quality, quantity and consistency in this data, as this paper explains, will allow for greater information to guide investment and ESG outcomes for Ti/Zr industries.
In this study, the application of the supercritical water technology on the management of waste printed circuit boards (PCBs) obtained from small information technology (IT) and communication equipment was conducted. Initially, an extensive recycling-oriented characterization of waste printed circuit boards was conducted through a combination of several physicochemical analyzes such as MP-AES, XRF, TG/DTA, CHNS elemental analysis, SEM and XRD. Afterwards, at supercritical conditions of water (Tc > 374.29 °C and Pc > 22.089 MPa), the optimal conditions for the degradation of the organic polymers present in the waste PCBs were defined by a response surface methodology. A complete organic degradation rate (ODR) was achieved at 600 °C, reaction time of 60 min, waste PCBs load of 15 g and flow-rate of 5 mL min⁻¹. After the removal of the organic polymers, the metals were liberated, and the metal recovery efficiency (MRE) reached values higher than 90% at all evaluated conditions. Then, initial insights on the subsequent treatment of the liquid decomposition by-products generated during the supercritical water (ScW) processing of waste PCBs were provided. A total organic carbon reduction of 99.88% was achieved via the ScW oxidation process using the same experimental apparatus. The treated solution was successfully re-used in the ScW processing of waste PCBs instead of clean water. Moreover, hydrogen, methane, CO2, and CO were identified as the major gaseous products associated to the supercritical water treatment of waste PCBs. Finally, a novel strategy to enhance the production of combustible gases, through the addition of ethanol and glycerol, and increase the economic feasibility of the supercritical water processing of waste PCBs was proposed.
By 2050, the global Earth population will reach 10 billion, leading to increased water, food, and energy needs. Availability of water in sufficient quantities and appropriate quality is a prerequisite for human societies and natural ecosystems. In many parts of the world, excessive water consumption and pollution by human activities put enormous pressure on this availability as well as on food and energy security, environmental quality, economic development, and social well-being. Water, food/materials, and energy are strongly interlinked, and the choices made in one area often have consequences on the others. This is commonly referred to as the “water-food-energy” nexus. These interconnections intensify as the demand for resources increases with population growth and changing consumption patterns, and Humanity continues using a linear economy model of ‘take-make-dispose’. The nexus makes it difficult for governments, public and private organisations, and the public, to set and follow a clear path towards a sustainable economy i.e “meeting the needs of the present without compromising the ability of future generations to meet their own needs”. Humanity best chance at mitigating climate change, and shortage of resources is to harness the value of water as much as possible, as shown below in a nutshell. This paper reviews the latest publications about the water-food-energy nexus and climate change, putting numbers into perspective, attempting to explain why water circularity is part of the key factors to accelerate the transition from a linear economy to a circular economy, and to meet the UN Sustainable Development Goals, and how circularity can be implemented in the water sector.
Zusammenfassung Die Bekämpfung des Klimawandels und die Erreichung der Nachhaltigen Entwicklungsziele der Vereinten Nationen machen eine Umstellung unseres Energiesystems weg von fossilen Brennstoffen hin zu erneuerbaren Energien unabdingbar. Mit dieser Energiewende gehen aber auch bedeutende Veränderungen des Rohstoffbedarfs einher. Vor allem die Nachfrage nach Metallen steigt stark an und damit auch Bedenken um mögliche negative Auswirkungen auf Menschen und Umwelt. Das Konzept der verantwortungsvollen Beschaffung hat es sich zum Ziel gesetzt diese Auswirkungen zu minimieren und für eine gerechte Verteilung von Vor- und Nachteilen entlang der Wertschöpfungsketten zu sorgen. Das EU-finanzierte Projekt RE-SOURCING beschäftigt sich mit den Lieferketten von drei Sektoren (erneuerbare Energie, Mobilität und Elektronik), die für eine erfolgreiche und faire Energiewende eine wichtige Rolle spielen. Sektorale State of Play Berichte und Roadmaps sollen Herausforderungen für nachhaltige Wertschöpfungsketten aufzeigen und Lösungen erarbeiten. Die Ergebnisse aus dem Sektor der erneuerbaren Energie zeigen zahlreiche Bereiche, wo rasches und entschiedenes Handeln erforderlich ist, um Menschenrechtsverletzungen und Umweltverschmutzung zu verhindern. Fünf Kernbereiche wurden bestimmt – Kreislaufwirtschaft und reduzierter Ressourcenverbrauch, Pariser Klimaabkommen und ökologische Nachhaltigkeit, soziale Nachhaltigkeit und verantwortungsvolle Produktion, verantwortungsvolle Beschaffung und gleiche Wettbewerbsbedingungen – für die notwendige Maßnahmen und entsprechende Handlungsempfehlungen identifiziert werden.
Metal mining plays a significant role in the Brazilian economy since its foundation as an overseas colony. The rapid increase in ore extraction brings along pressures on the country’s water resources, as mining is a particularly water-intensive activity. However, site-specific data on water input and management are scarce. We propose a methodology for estimating water input in mining at a high geographical resolution. We focus on the three key metals mined in Brazil: iron, aluminum (i.e. bauxite ore), and copper, and derive water input coefficients for all mines from governmental and corporate sources as well as from the literature. We estimate that overall, the sum of the water inputs estimated for Brazilian bauxite, copper, and iron ore mining decreased by 15% from an average of 506.5±62.4 hm³ in 2014 to an average of 408.4±67.2 hm³ in 2017. The regions where most water was appropriated were Northern (Pará state) and Southeast (Minas Gerais) for iron, Northern (Pará) for aluminum, and Northern (Pará) and Central West (Goiás) for copper. We show that there are still significant consistency and data availability gaps, and that further work is still necessary to improve site-specific reporting and open access to data collected by public institutions.
Full-text available
In recent decades, changes that human activities have wrought in Earth’s life support system have worried many people. The human population has doubled in the past 40 years and is projected to increase by the same amount again in the next 40. The expansion of infrastructure and agriculture necessitated by this population growth has quickened the pace of land transformation and degradation. We estimate that humans have modified >50% of Earth’s land surface. The current rate of land transformation, particularly of agricultural land, is unsustainable. We need a lively public discussion of the problems resulting from population pressures and the resulting land degradation. *Email: Manuscript received 14 Feb. 2012; accepted 16 Aug. 2012 DOI: 10.1130/GSAT151A.1
Full-text available
Water is vital to the mining industry; mines can require substantial amounts of water and are often located in some of the driest places on earth. Reducing water withdrawals and improving mine water use are key strategic requirements for moving toward a more sustainable mining industry. Mine water requirements often have significant technical, economic, environmental and political implications. This thesis quantifies global mine water withdrawals and discusses methods of improving mine water use by reducing water withdrawals and water-related energy consumption.
Full-text available
The ‘Great Acceleration’ graphs, originally published in 2004 to show socio-economic and Earth System trends from 1750 to 2000, have now been updated to 2010. In the graphs of socio-economic trends, where the data permit, the activity of the wealthy (OECD) countries, those countries with emerging economies, and the rest of the world have now been differentiated. The dominant feature of the socio-economic trends is that the economic activity of the human enterprise continues to grow at a rapid rate. However, the differentiated graphs clearly show that strong equity issues are masked by considering global aggregates only. Most of the population growth since 1950 has been in the non-OECD world but the world’s economy (GDP), and hence consumption, is still strongly dominated by the OECD world. The Earth System indicators, in general, continued their long-term, post-industrial rise, although a few, such as atmospheric methane concentration and stratospheric ozone loss, showed a slowing or apparent stabilisation over the past decade. The post-1950 acceleration in the Earth System indicators remains clear. Only beyond the mid-20th century is there clear evidence for fundamental shifts in the state and functioning of the Earth System that are beyond the range of variability of the Holocene and driven by human activities. Thus, of all the candidates for a start date for the Anthropocene, the beginning of the Great Acceleration is by far the most convincing from an Earth System science perspective.
Full-text available
We have assembled extensive information on the cradle-to-gate environmental burdens of 63 metals in their major use forms, and illustrated the interconnectedness of metal production systems. Related cumulative energy use, global warming potential, human health implications and ecosystem damage are estimated by metal life cycle stage (i.e., mining, purification, and refining). For some elements, these are the first life cycle estimates of environmental impacts reported in the literature. We show that, if compared on a per kilogram basis, the platinum group metals and gold display the highest environmental burdens, while many of the major industrial metals (e.g., iron, manganese, titanium) are found at the lower end of the environmental impacts scale. If compared on the basis of their global annual production in 2008, iron and aluminum display the largest impacts, and thallium and tellurium the lowest. With the exception of a few metals, environmental impacts of the majority of elements are dominated by the purification and refining stages in which metals are transformed from a concentrate into their metallic form. Out of the 63 metals investigated, 42 metals are obtained as co-products in multi output processes. We test the sensitivity of varying allocation rationales, in which the environmental burden are allocated to the various metal and mineral products, on the overall results. Monte-Carlo simulation is applied to further investigate the stability of our results. This analysis is the most comprehensive life cycle comparison of metals to date and allows for the first time a complete bottom-up estimate of life cycle impacts of the metals and mining sector globally. We estimate global direct and indirect greenhouse gas emissions in 2008 at 3.4 Gt CO2-eq per year and primary energy use at 49 EJ per year (9.5% of global use), and report the shares for all metals to both impact categories.
In this paper, we demonstrate that climate change is critically important for the current and future status of mining activity and its impacts on surrounding communities and environments. We illustrate this through examples from Latin America, including a spatial analysis of the intersection between projected climate changes and existing mining operations. We then elaborate a framework to identify and investigate the relationships among mining, climate change, and public and private responses to them. The framework also notes the importance of political economy and learning processes to the forms taken by these relationships. Our paper then reports on a focused review of peer-reviewed publications that aims to identify the extent to which a core research literature on mining and climate change currently exists. We show that this literature is still very limited, but that the analysis that does exist can be encapsulated by the main elements of our framework. This enables us to describe the current structure of both peer-reviewed and policy research on mining and climate change, and identify areas for future research. In particular, we note the chronic absence of research on this relationship for the vast majority of developing countries, where some of the most serious vulnerabilities to climate change exist.
The need for identifying and delivering changes to reduce energy usage and greenhouse gas (GHG) emissions is evolved with the introduction of the Australian Government's Carbon Pollution Reduction Scheme (CPRS). Several significant factors are combined to increase total energy use and emissions like increased stripping ratios, greater mining depths, lower ore grades, and increased production. Orica's Blast Based Service (BBS) are aimed to expose more coal for the same amount of energy used or maximizing coal recovery for the same amount of energy consumption. It can provide assistance for reducing GHG intensity and improving the profitability of the mining operations. BBS is aimed to contribute to the reduction or risk management of GHG intensity through blasts producing improved fragmentation for higher mill throughput and reduced ore dilution.
The energy, greenhouse gas (GHG) emissions and water intensity, or environmental footprints, of global primary copper production have been estimated. The primary data have been collected from the sustainability reports published by copper producing mines, operations and companies. The mines analysed in this paper are from Australia, Chile, Peru, Argentina, Laos, Papua New Guniea, South Africa, Turkey, Finland, the USA and Canada. The typical range of energy intensity was found to be 10–70 GJ/t Cu, with an average of 22.2 GJ/t Cu. The range of GHG emissions was 1–9 t CO2-e/t Cu, with an average of 2.6 t CO2-e/t Cu. The large variation exists largely due to the form of copper produced, ore grade, sources of fuel and electrical energy, and to a lesser extent the reporting methods and procedures used by the companies. The water footprint averages 70.4 kL/t Cu but can range from several kilolitres to up to 350 kL/t Cu. Variation in water intensity is generally due to inconsistencies in reporting method, the geographical location of the mining operations, limited economies of scale of production site, and the climate type (i.e. arid regions in Australia and Chile or temperate to sub-arctic climates in Canada or Finland). It is recommended that company sustainability reports should clearly specify fuel use by type for vehicles, heat or electrical energy, sources of electricity and their mixes (including GHG emissions factors), and the boundaries of the operation for meaningful use in life cycle assessment (LCA). Sustainability reports should be published at regular intervals so that improvements towards more sustainable performance can be measured, and an LCA of mining activities can be developed for primary copper production more readily. The paper provides a valuable insight into the strong value of sustainability reporting for an industrial sector such as copper mining and how such data can be linked to LCA studies.
The environmental profile of gold production with regards to embodied energy, greenhouse gas emissions, embodied water and solid waste burden has been assessed using life cycle assessment methodology. Both refractory and non-refractory ores were considered, with cyanidation extraction followed by carbon in pulp (CIP) recovery assumed for non-refractory ore processing. Flotation and pressure oxidation were included prior to cyanidation for processing refractory ores. For a base case ore grade of 3.5 g Au/t ore, the life cycle-based environmental footprint of gold production was estimated to be approximately 200,000 GJ/t Au, 18,000 t CO2e/t Au, 260,000 t water/t Au and 1,270,000 t waste solids/t Au for non-refractory ore. The embodied energy and greenhouse gas footprints were approximately 50% higher with refractory ore due to the additional material and energy inputs and gold and silver losses associated with the additional processing steps required with this ore. The solid waste burden was based on an assumed strip ratio of 3 t waste rock/t ore, but this ratio varies considerably between mines, significantly influencing the estimated value of this impact. The environmental footprint of gold production (per tonne of gold produced) was shown to be several orders of magnitude greater than that for a number of other metals, largely due to the low grades of ore used for the production of gold compared to other metals.