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BENCHMARKING THE ENERGY CONSUMPTION OF
CANADIAN OPEN-PIT MINES
PREPARED FOR MINING ASSOCIATION OF CANADA
NATURAL RESOURCES CANADA
AND
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Page 4
For more information or to receive additional copies of this publication, write to:
Canadian Industry Program for Energy Conservation
c/o Natural Resources Canada
580 Booth Street, 18th Floor
Ottawa ON K1A 0E4
Tel.: (613) 995-6839
Fax: (613) 992-3161
E-mail: cipec-peeic@nrcan.gc.ca
Web Site: oee.nrcan.gc.ca/cipec
Or
Mining Association of Canada
350 Sparks St. Suite 1105
Ottawa ON K1R 7S8
Tel: (613) 233-9391
Fax: (613) 233-8897
Web Site: www.mining.ca
Library and Archives Canada Cataloguing in Publication
Main entry under title :
Benchmarking the energy consumption of Canadian open-pit mines
Issued also in French under title: Analyse comparative de la consommation
d’énergie des mines à ciel ouvert du Canada.
ISBN 0-662-39538-7
Cat. No. M144-70/2005E
1.
2.
3.
4.
5.
I.
II.
Strip mining – Energy consumption – Canada.
Strip mining – Energy conservation – Canada.
Energy consumption – Canada.
Energy conservation – Canada.
Energy auditing – Canada.
Canadian Industry Program for Energy Conservation.
Mining Association of Canada.
TN291.B46 2005
622’.292’0682
C2005-980101-8
© Her Majesty the Queen in Right of Canada, 2005
Recycled paper
FOREWORD
FOREWORD
I
On behalf of the Mining Sector Task Force of the Canadian Industry Program for Energy
Conservation (CIPEC), the Mining Association of Canada (MAC) retained Corporate
Renaissance Group to work with mining companies to establish energy benchmarks for
open-pit mines. Companies that participated in this project paid for the on-site services
of the consultancy and have received individualized reports on the findings.
CIPEC consists of 26 task forces, representing the various industrial sectors in Canada,
and is a partnership of industrial associations and the Government of Canada, represented
by Natural Resources Canada’s Office of Energy Efficiency. The Mining Sector Task Force
comprises members of MAC’s Energy Committee. CIPEC task forces act as focal points
for identifying energy efficiency potential and improvement opportunities, establishing sector
energy efficiency targets, reviewing and addressing barriers, and developing and implementing
strategies to meet the targets.
This publication is one of a series of MAC publications demonstrating the mining industry’s
commitment to energy conservation and the reduction of greenhouse gas emissions – a
commitment essential to our common well-being. Among our members, good energy
practices are simply accepted as being good business practices.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
TABLE OF CONTENTS
Leading Canadian to Energy Efficiency at Home, at Work and on the Road
III
The Office of Energy Efficiency of Natural Resources Canada
strenghens and expands Canada’s commitment to energy efficiency
in order to help address the challenges of climate change.
TABLE OF CONTENTS
1. INTRODUCTION . . . . . .
1.1 Background . . . .
1.2 Focus . . . . . . . .
1.3 Layout of Report
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1
2
2
3
2. METHODOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Boundaries of the Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.1 Gold and Iron Ore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.2 Oil Sands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 The Mining Association of Canada (MAC) Sample . . . . . . . . . . . . . . . . . . . . . . 7
2.2.1 Analysis: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2.2 Comparative Energy Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2.3 Analysis: Open-Pit Mining Operations . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2.4 Analysis: Milling Operations – Gold Recovery . . . . . . . . . . . . . . . . . . . 10
2.2.5 Analysis: Concentrator Operations – Iron Ore . . . . . . . . . . . . . . . . . . . 12
2.2.6 General and Administrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3. RESULTS: BENCHMARKING PARTICIPATING MINES . . . . . . . . . . . . . . . . . . . . . . . .
3.1 Comparative Unit Costs for Energy . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Inter-Mine Comparative Energy Costs – Total Operations . . . . . . . . . .
3.3 Inter-Mine Comparative Energy Costs – Mining Operations . . . . . . . . .
3.3.1 Total Mining Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.2 Waste Rock Operations – Stages of Production . . . . . . . . . . . . .
3.3.3 Ore Mining Operations – Stages of Production . . . . . . . . . . . . .
3.3.4 Comparisons Based on Total Material Removed . . . . . . . . . . . .
3.4 Inter-Mine Comparative Energy Costs – Mill/Concentrator Operations
3.4.1 Total Mill/Concentrator Operations . . . . . . . . . . . . . . . . . . . .
3.4.2 Mill/Concentrator Operations – Stages of Production . . . . . . . .
3.5 General and Administrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4. POTENTIAL SAVINGS: ACHIEVING BENCHMARK STANDARDS
4.1 Context . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 Potential Energy Savings: Mining . . . . . . . . . .
4.3 Potential Energy Savings: Milling . . . . . . . . . .
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BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
1
INTRODUCTION
1 INTRODUCTION
1. INTRODUCTION
2
1.1 Background
Energy costs represent a significant component of the total costs of operations for Canada’s
mining sector. Directly and indirectly, the energy use in the mining sector is also a significant
contributor to Canada’s greenhouse gas emissions. Improving energy efficiency reduces
greenhouse gas emissions that contribute to climate changes. There are, therefore, compelling
economic and environmental reasons for mining and milling operations to examine their
energy consumption comprehensively.
The Mining Association of Canada (MAC) has sponsored this energy benchmarking project.
The focus is a detailed comparison of the energy consumption for open-pit mining and
concentration activities. The Office of Energy Efficiency of Natural Resources Canada
(NRCan) has provided assistance for this study, which is a part of NRCan’s ongoing efforts
to promote more efficient energy use in Canada.
1.2 Focus
The focus of this analysis is the mining and concentration operations of open-pit mines of
MAC members. Nine mining/milling operations participated in the project, and the sample
specifically included the operations of gold, oil sands and iron ore establishments.
The project involved a detailed inter-facility comparison of the energy consumed in mining
(drilling – transport) and concentration (crushing – tailings disposal). Approximately
25 categories of energy cost and usage information were examined.
Given the significantly different nature of the milling/concentrator operations for gold
and iron ore operations, energy comparisons for these aspects of the operations have been
aggregated into larger groupings where feasible. The oil sands operations are compared
only with regard to their mining activities.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
INTRODUCTION
1.3 Layout of Report
3
We begin by outlining our methodology in Section 2. We describe our approach for
developing energy cost comparisons ($/kilotonne mined; $/kilotonne milled) to analyse
the operations of the study participants.
Section 3 presents the results of the detailed benchmarking of energy costs and usage for
the nine participating establishments. Inter-establishment comparisons are presented at the
mine and mill levels, as well as at the various stages of production.
Section 4 presents results on the potential savings generated by achieving benchmark
standards. Comparing the costs for each participant with those for the lowest-cost operations
produces the estimated potential savings.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
1
2
METHODOLOGY
2 METHODOLOGY
2. METHODOLOGY
6
2.1 Boundaries of the Analysis
The focus of the analysis of comparative energy costs and usage was as follows:
2.1.1 Gold and Iron Ore
The gold and iron ore energy analysis focused on mining and milling/concentration operations.
Smelting,
Refining,
Etc.
Ongoing
Exploration
Mining
Concentration
FOCUS OF ANALYSIS
2.1.2 Oil Sands
The oil sands energy analysis focused on the mining operations.
Overburden
Removal
Mining
HydroTransport
FOCUS OF ANALYSIS
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
METHODOLOGY
2.2 The Mining Association of Canada (MAC) Sample
7
A total of nine establishments participated in this project. Each case study included an
open-pit mining facility. For seven of the nine mines, energy information was provided for
milling/concentrator operations. These included four gold recovery operations producing
gold bars and three iron ore operations producing concentrates.
Open-Pit Operations (9 facilities)
Mill/Contractor Operations
Gold Recovery (4 facilities)
Iron Ore (3 facilities)
2.2.1 Analysis: Overview
The objective of the analysis is to provide a detailed inter-facility comparison of the cost
per kilotonne mined and processed, split into costs per unit of energy and energy consumed
per kilotonne for the following:
Open-Pit Mining
Nine mining operations will be compared – all operations, including the transport of ore
to the crusher.
Milling/Concentrator Operations (Gold Recovery and Iron Ore Concentration)
The analysis will reflect comparisons of energy consumption and costs for the four gold
recovery facilities and three iron ore facilities and will include crushing, grinding and the
aggregate of all production stages beyond grinding to loadout, plus process water, tailings
disposal and support services.
A more detailed process comparison would not be meaningful due to the radically different
processes followed by the companies. However, a more detailed analysis of each company’s
milling/concentrator processes was presented to the individual companies involved in the
study.
In all cases, energy consumption will be based on kilowatt hour equivalents (kWhe). The
conversion factors for other categories of energy are illustrated below. These conversions
are derived from energy content factors reported in Canada’s Energy Outlook 1996–2000,
Natural Resources Canada, April 1997, page D-3.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
2
2 METHODOLOGY
Table 2.1 – Conversion Factors (kWhe)
8
Energy
Units
kWhe/Unit
Diesel
L
10.74
Gasoline
L
9.63
Natural Gas
m3
10.31
Explosives
kg
1.06
Light Fuel Oil
L
10.40
Bunker C Oil
L
11.59
The inter-facility comparisons are based on the following unit costs and disaggregation
into components for open-pit mining and milling/concentrator facilities.
Open-Pit Mining (Gold, Iron Ore and Oil Sands)
=
[
kWhe
[
[
kilotonne
ore mined
$
X
[
kWhe
kilotonne
ore mined
[
[
$
Milling/Concentrator (Gold and Iron Ore)
=
[
kWhe
[
[
kilotonne
ore milled
$
X
[
kWhe
kilotonne
ore milled
[
[
$
Note:
One KILOTONNE
kilotonne = 2.204623
million
pounds POUNDS
NOTE
: ONE
= 2.204623
MILLION
Total Complex
For the total complexes, the unit energy costs and consumption will be based on a roll-up
of the above. Given that some milling/concentrator operations process ore from more
than one open pit and that certain operations use different processes for different
qualities/types of ore, the data for the total complex is based on:
a. the average mining energy costs and usage for the facility in the study; and
b. actual costs and usage for the energy used in milling/concentrator operations.
Given the above assumptions, the total energy costs can be subdivided to calculate the cost
per kilotonne milled for both gold and iron ore.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
METHODOLOGY
2.2.2 Comparative Energy Costs
Not surprisingly, average energy unit costs by source vary among the nine open-pit mines.
9
Energy source (e.g. electricity)
$/kWh
1
9
2.2.3 Analysis: Open-Pit Mining Operations
The open-pit mining operations were subdivided into 10 stages of production and three
support activities. These categories are illustrated below.
Stages of
Production
Drilling
Blasting
Support Activities
Mine Support Equipment
Waste Rock
Removal
Excavating
Road Maintenance
Transportation
Service Equipment
Waste Rock Disposal
Drilling
Blasting
Ore
Extraction
Excavating
Ore Transport
Pit Dewatering
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
2
2 METHODOLOGY
The total energy costs for open-pit mining operations for the nine operations were compared.
10
$/kilotonne
ore mined
1
9
These energy costs were, in turn, subdivided into two components: $/kWhe and
kWhe/kilotonne of ore mined.
$/kWhe
1
9
1
9
kWhe /kilotonne
ore mined
Similarly, energy costs and consumption were compared for each of the nine operations by
stage of production.
2.2.4 Analysis: Milling Operations – Gold Recovery
The gold recovery milling operations were subdivided into the following stages of production
and support activities.
Crushing
Support Activities
Plant Services
Stages of
Production
Grinding
Process Water
Additional Processing of Milled Ore
Tailings Disposal
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
METHODOLOGY
The total energy costs for the milling process in the four gold recovery operations were
compared.
11
$/kilotonne
milled
1
4
These energy costs were, in turn, subdivided into two components: $/kWhe
and kWhe/kilotonne ore milled.
$/kWhe
1
4
1
4
kWhe/kilotonne
milled
The total energy costs were compared for each of the milling gold recovery production
stages (crushing, grinding and additional processing through to tailings treatment and
disposal). In each case, the total energy costs/kilotonne milled, $/kWhe and kWhe/kilotonne
milled were compared as illustrated above for the mining operations.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
2
2 METHODOLOGY
2.2.5 Analysis: Concentrator Operations – Iron Ore
12
The iron ore concentration facilities were subdivided into the following stages of production
and support facilities.
Crushing
Grinding
Stages of
Production
Additional Processing *
Support Activities
Separation
Plant Services
Filtration
Tailings Treatment
Process Water
Drying
Loadout
*
NOTE:
STUDY
PARTICIPANTS FOLLOWED MATERIALLY DIFFERENT PROCESSES FOR PRODUCTION STAGES RELATED TO SEPARATION,
FILTRATION AND DRYING.
TO
ACHIEVE MEANINGFUL COMPARISONS OF ENERGY CONSUMPTION FOR THESE STAGES, IT WAS
NECESSARY TO AGGREGATE THE DATA UNDER THE HEADING
“ADDITIONAL
PROCESSING” EVEN THOUGH ENERGY CONSUMPTION
FOR THESE STAGES WAS REPORTED TO THE INDIVIDUAL COMPANIES.
As in the case of the gold operations, the total energy costs per kilotonne for the three
concentrator operations were compared. These energy costs were, in turn, divided into
their two subcomponents: $/kWhe and kWhe/tonne processed.
The above comparisons were made for each stage of production in the concentration
process: crushing, grinding and separation through to tailings treatment and disposal.
2.2.6 General and Administrative
The costs for general and administrative activities were compared separately for both gold
and iron ore mining. As in the case of the mining and milling/concentrator analysis, the
total energy cost for general and administrative activities per kilotonne mined was determined. This number, in turn, was broken down into its cost per kilowatt hour equivalent
and the kilowatt hour equivalent per kilotonne mined.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
RESULTS:
BENCHMARKING
PARTICIPATING
MINES
3 RESULTS: BENCHMARKING PARTICIPATING MINES
3. RESULTS: BENCHMARKING PARTICIPATING MINES
14
As mentioned above, the nine participants in the study included three iron ore mines, four
gold mines and two oil sands operations (for which only mining energy data were collected).
In all cases, the mine operations reported their energy consumption and costs for the full
calendar year 2000.
For the nine mines, total energy expenditures of $228 million were incurred for the calendar
year 2000. The most heavily used fuels were diesel (235 million litres) and electricity
(2265 gigawatt hours). Together, these two energy sources accounted for more than
75 percent of the total energy (kWhe) consumed at the mines.
The mines in the sample collectively produced over 260 million tonnes of ore during
2000 and removed a comparable amount of waste rock. The volume of ore mined during
the year varied from less than 4 million tonnes to over 60 million tonnes at the largest
mine. Total material removed (ore plus waste rock) ranged from just under 20 million
tonnes to over 120 million tonnes. Stripping ratios (waste rock : ore tonnage) varied
considerably, from 0.04 to 6.05. This variation has a significant influence on the costs and
energy consumption per tonne of ore mined that is reported in Sections 3.2 and 3.3 of this
study. In Section 3.4, however, we compare the mining operations on the basis of total
tonnage removed (ore plus waste), a comparison that removes the influence of the stripping
ratios on the comparisons.
The energy benchmarking results will be presented as we compare:
1. the costs across the participants for the individual energy sources;
2. the mining operations for the nine establishments; and
3. the results for the concentration operations of seven facilities.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
RESULTS: BENCHMARKING PARTICIPATING MINES
3.1 Comparative Unit Costs for Energy
15
There are very significant differences between the lowest and highest unit costs reported
for the sources of energy used at the mining operations in the study sample. As illustrated below, the range of unit costs for each energy category is very wide (from 118 to
3 849 percent). The unit energy costs are compared in the figures below.
Figure 3.1 – Range of Unit Energy Costs
Highest as
% of Lowest
3 849
4 000
3 500
3 000
2 500
2 000
1 500
1 000
118
177
208
225
Bunker C
Oil
Gasoline
Diesel
Blasting
Fuels
500
0
341
Propane
Electricity
Figure 3.2 – Comparative Unit Energy Costs (CAN$)
Electricity ($/kWh)
$/kWh
0.10
0.083
0.092
0.08
0.057
0.06
0.04
0.02
0.002
0.004
1
2
0.035
0.039
0.039
0.042
3
4
5
6
0.37
0.38
0.39
0.40
3
4
5
6
0.00
7
8
0.43
0.43
7
8
9
Diesel ($/litre)
$/litre
0.48
0.50
0.40
0.30
0.33
0.23
0.20
0.10
0.00
1
2
9
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Figure 3.2 (cont.) – Comparative Unit Energy Costs (CAN$)
16
Gasoline ($/litre)
$/litre
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
0.38
0.57
0.59
0.59
0.59
3
4
5
6
0.65
0.67
7
8
0.45
1
2
Propane ($/litre)
$/litre
0.94
1.00
0.80
0.54
0.60
0.40
0.44
0.28
0.29
0.33
1
2
3
0.20
0.00
4
5
6
Blasting Fuels ($/kg of explosive)
$/kg
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
0.72
0.67
0.44
0.32
0..33
1
2
3
0.49
0.50
4
5
6
7
Bunker C Oil ($/litre)
$/litre
0.24
0.25
0.20
0.20
0.20
1
2
0.15
0.10
0.05
0.00
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
RESULTS: BENCHMARKING PARTICIPATING MINES
3.2 Inter-Mine Comparative Energy Costs – Total Operations
17
Sufficient information was received from seven open-pit mining operations to make comparisons at the “total operations” level (mining and milling/concentrating costs and energy
consumption per kilotonne of ore mined or processed) and for each of the stages of production (drilling, blasting, loading/excavating, hauling, crushing, grinding, etc.). For the
two oil sands projects in the sample, only mining data was collected. For heap leach gold
mines in the sample, costs were separated for ore destined for the milling process versus ore
treated on leach pads, and the “mill ore” costs are reported here.
In all cases, the energy costs were compared based on Canadian dollars per kilotonne
(million kilograms 1) of ore mined. These unit costs, in turn, were subdivided into an energy
cost component (dollars per kWh equivalent) and a usage component (kWh equivalent per
kilotonne of ore mined). The energy costs for total operations represent the average cost
per kilotonne of ore mined plus the average cost per kilotonne of ore milled/concentrated.
This concept is captured using the phrase “$ per kilotonne of ore processed” (i.e. processed
in the mining and the concentrating operations). The figure below summarizes the total
energy costs per kilotonne of ore mined and ore milled/concentrated for the seven mines
that reported all data for this study.
1 ONE
TONNE
(1 000
KILOGRAMS) EQUALS
2 204.6
LBS.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Figure 3.3 – Energy Costs: Total Operations
18
Energy Cost
$ per kilotonne
of ore processed
5 000
4 165
4 482
4 000
2 855
3 000
2 106
2 000
1 000
639
888
1
2
1 266
0
3
4
5
6
7
Energy Consumption
kWhe per kilotonne
of ore processed
80 000
70 000
60 000
50 000
40 000
30 000
20 000
10 000
0
71 104
62 387
46 274
26 917
31 414
33 065
1
2
3
4
53 301
5
6
7
0.063
0.064
0.067
5
6
7
Unit Energy Cost
$ per kWhe
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0.00
0.047
0.019
0.020
1
2
3
0.054
4
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
Blasting
26.52
170.52
Blasting
Waste Rock Removal
720.15
34.91
Total Mining
1 189.33
G&A
449.61
19.57
Other Plant 18.52
24.85
Process Water
163.17
33.75
174.41
Tailings
Other Processing
Grinding
Crushing
46.07
24.46
Ore
Excavation
Mine Support
Dewatering
88.75
24.38
182.78
301.62
Transport
Excavating
Drilling 5.71
21.38
116.43
348.00
Handling
Transport
Excavation
Drilling 13.15
Weighted Average $/kilotonne
RESULTS: BENCHMARKING PARTICIPATING MINES
Figure 3.4 – Average Costs by Stage of Production
Total Operations
19
Total Mill/Concentrator Operations
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
Transport
2 793
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
Other Processing
Grinding
1 320
1 419
Total
Mining
Crushing
11 766
Mine Support
Ore
Excavation
Dewatering 355
4 301
784
453
Waste Rock Removal
Transport
Excavating
Blasting
Drilling 271
636
3 492
5 691
Handling
693
504
Blasting
Excavation
366
Drilling
5 269
752
1 647
33 507
G&A
20 989
Other Plant
1 527
1 754
9 473
Process Water
Tailings
Weighted Average kWhe /kilotonne
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Figure 3.5 – Average Energy Consumption by Stage of Production
20
Total Operations
Total Mill/Concentrator Operations
RESULTS: BENCHMARKING PARTICIPATING MINES
3.3 Inter-Mine Comparative Energy Costs – Mining Operations
21
3.3.1 Total Mining Operations
The total energy costs for open-pit mining for the nine operations are shown below. As
illustrated, the energy costs vary from $170 per kilotonne of ore mined to $3,120 per
kilotonne. The range of costs and efficiencies is as follows:
Energy Cost ($/kilotonne of ore mined)
Energy Consumption (kWhe/kilotonne of ore mined)
Unit Energy Cost ($/kWhe)
Range
High : Low
High : Low
Percent
3 120 : 170
1 830
42 474 : 7 006
606
0.073 : 0.022
331
The total costs shown here cover drilling, blasting, excavating, hauling, pit dewatering, and
mine support equipment, road maintenance and service equipment. Any in-pit crushing or
rehandling of ore from stockpiles is excluded.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Figure 3.6 – Total Energy Costs: Mining Operations
22
Energy Cost
$ per kilotonne
of ore mined
3 500
3 000
2 500
2 000
1 500
1 000
500
0
3 120
1 793 1 821
170
231
1
2
527
534
552
3
4
5
817
6
7
8
9
Energy Consumption
kWhe per kilotonne
of ore mined
50 000
42 474
40 000
33 855
26 884
30 000
20 000
10 000
10 321 11 264
7 006 7 694 8 949
13 322
0
1
2
3
4
5
6
7
8
9
Unit Energy Cost
$ per kWhe
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0.00
0.053
0.049 0.052
0.059 0.061
0.068
0.073
0.033
0.022
1
2
3
4
5
6
7
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
8
9
RESULTS: BENCHMARKING PARTICIPATING MINES
3.3.2 Waste Rock Operations – Stages of Production
23
Drilling (Waste Rock)
The cost for waste rock drilling energy varied from $0.08 to $144.00 per kilotonne of ore
mined for seven drilling operations. The range of costs and efficiencies is as follows:
Range
High : Low
Energy Cost ($/kilotonne of ore mined)
High : Low
Percent
144.00 : 0.08
179 800
Energy Consumption (kWhe/kilotonne of ore mined)
3 618 : 35
10 439
Unit Energy Cost ($/kWhe)
0.045 : 0.002
1 858
Figure 3.7 – Drilling (Waste Rock) Energy Costs
Energy Cost
$ per kilotonne
of ore mined
144.00
150
120
81.00
90
60
44.00
30
0
0.08
1
0.43
6.00
8.00
2
3
4
5
6
7
Energy Consumption
kWhe per kilotonne 4 000
of ore mined 3 500
3 000
2 500
2 000
1 500
1 000
500
0
3 618
1 806
1 208
35
103
177
200
1
2
3
4
5
6
0.037
0.039
0.040
4
5
6
7
Unit Energy Cost
$ per kWhe
0.05
0.045
0.04
0.034
0.03
0.02
0.01
0.002
0.004
1
2
0.00
3
7
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Blasting (Waste Rock)
24
The blasting energy costs for waste rock varied from $79 to $1,255 per kilotonne of ore
mined. The range of costs and efficiencies is as follows:
Range
High : Low
High : Low
Percent
Energy Cost ($/kilotonne of ore mined)
1 255 : 79
Energy Consumption (kWhe/kilotonne of ore mined)
1 845 : 203
909
Unit Energy Cost ($/kWhe)
0.680 : 0.186
366
Figure 3.8 – Blasting (Waste Rock) Energy Costs
Energy Cost
$ per kilotonne
of ore mined
1 500
1 255
1 200
900
516
600
300
79
84
101
1
2
3
205
239
4
5
0
6
7
Energy Consumption
kWhe per kilotonne
of ore mined
1 845
2 000
1 500
1 221
1 383
1 000
500
425
203
217
1
2
535
0
3
4
5
6
7
Unit Energy Cost
$ per kWhe
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
0.680
0.186
0.196
1
2
0.373
0.384
0.415
3
4
5
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
0.466
6
7
1 588
RESULTS: BENCHMARKING PARTICIPATING MINES
Loading/Excavating (Waste Rock)
The energy costs for loading/excavating waste rock varied from $5 to $277 per kilotonne
of ore mined. The range of costs and efficiencies is as follows:
Range
High : Low
Energy Cost ($/kilotonne of ore mined)
25
High : Low
Percent
277 : 5
5 213
Energy Consumption (kWhe/kilotonne of ore mined)
6 209 : 332
1 868
Unit Energy Cost ($/kWhe)
0.054 : 0.016
341
Figure 3.9 – Excavating (Waste Rock) Energy Costs
Energy Cost
$ per kilotonne
of ore mined
300
250
200
150
100
50
0
277
175
5
1
11
14
18
21
2
3
4
5
40
6
61
7
8
9
Energy Consumption
kWhe per kilotonne
of ore mined
8 000
7 000
6 000
5 000
4 000
3 000
2 000
1 000
0
6 209
3 750
332
336
380
424
658
1
2
3
4
5
1 089 1 140
6
7
8
9
Unit Energy Cost
$ per kWhe
0.06
0.05
0.04
0.03
0.02
0.01
0.00
0.053 0.054
0.045 0.047
0.032
0.037 0.037
0.025
0.016
1
2
3
4
5
6
7
8
9
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Waste Rock Transport
26
The energy costs for hauling waste rock varied from $18 to $887 per kilotonne of ore
mined. The range of costs and efficiencies is as follows:
Range
High : Low
High : Low
Percent
887 : 18
4 986
Energy Cost ($/kilotonne of ore mined)
Energy Consumption (kWhe/kilotonne of ore mined)
22 307 : 442
Unit Energy Cost ($/kWhe)
0.045 : 0.021
Figure 3.10 – Waste Rock Transport Energy Costs
Energy Cost
$ per kilotonne
of ore mined
1 000
887
800
579
600
338
400
200
0
18
1
54
69
75
2
3
4
114
126
5
6
7
8
9
Energy Consumption
kWhe per kilotonne
of ore mined
25 000
22 307
20 000
15 817
15 000
10 000
7 577
5 000
442
3 211 3 229 3 670
1 461 2 421
0
1
2
3
4
5
6
7
8
9
Unit Energy Cost
$ per kWhe
0.05
0.045
0.04
0.031
0.034 0.035 0.037 0.037
0.040 0.040
0.03
0.021
0.02
0.01
0.00
1
2
3
4
5
6
7
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
8
9
5 052
208
RESULTS: BENCHMARKING PARTICIPATING MINES
Waste Rock Handling
The energy costs for handling waste rock after transport varied from $7 to $78 per kilotonne
of ore mined. The range of costs and efficiencies is as follows:
Range
High : Low
High : Low
Percent
78 : 7
1 076
Energy Cost ($/kilotonne of ore mined)
Energy Consumption (kWhe/kilotonne of ore mined)
1 743 : 298
586
Unit Energy Cost ($/kWhe)
0.045 : 0.021
208
27
Figure 3.11 – Waste Rock Handling Energy Costs
Energy Cost
$ per kilotonne
of ore mined
80
70
60
50
40
30
20
10
0
78
7
10
13
1
2
3
19
23
4
5
29
32
6
7
39
8
9
Energy Consumption
kWhe per kilotonne
of ore mined
2 000
1 743
1 500
1 036 1 079
1 000
500
298
337
345
1
2
3
538
567
4
5
736
0
6
7
8
9
Unit Energy Cost
$ per kWhe
0.05
0.04
0.031
0.037
0.034 0.035 0.037
0.040 0.040
0.045
0.03
0.021
0.02
0.01
0.00
1
2
3
4
5
6
7
8
9
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
3.3.3 Ore Mining Operations – Stages of Production
28
Drilling (Ore)
The drilling energy costs varied from $0.13 to $29.00 per kilotonne of ore mined for
seven drilling operations. The range of costs and efficiencies is as follows:
Energy Cost ($/kilotonne of ore mined)
Range
High : Low
High : Low
Percent
29.00 : 0.13
21 969
641 : 54
1 191
0.045 : 0.002
1 858
Energy Consumption (kWhe/kilotonne of ore mined)
Unit Energy Cost ($/kWhe)
Figure 3.12 – Drilling (Ore) Energy Costs
Energy Cost
$ per kilotonne
of ore mined
29.00
30
25
20
15
10
5
0
24.00
0.13
1
7.00
7.00
3
4
10.00
2.00
2
5
6
7
599
641
7
Energy Consumption
kWhe per kilotonne
of ore mined
800
700
600
500
400
300
200
100
0
385
185
217
2
3
281
54
1
4
5
6
0.037
0.039
0.040
4
5
6
Unit Energy Cost
$ per kWhe
0.05
0.045
0.04
0.034
0.03
0.02
0.01
0.002
0.004
1
2
0.00
3
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
7
RESULTS: BENCHMARKING PARTICIPATING MINES
Blasting (Ore)
The energy costs for blasting ore varied from $56 to $208 per kilotonne of ore mined.
The range of costs and efficiencies is as follows:
Range
High : Low
High : Low
Percent
Energy Cost ($/kilotonne of ore mined)
208 : 56
374
Energy Consumption (kWhe/kilotonne of ore mined)
520 : 284
183
0.680 : 0.186
366
Unit Energy Cost ($/kWhe)
29
Figure 3.13 – Blasting (Ore) Energy Costs
Energy Cost
$ per kilotonne
of ore mined
250
200
164
183
186
202
208
150
100
97
56
50
0
1
2
3
4
5
6
7
482
488
492
520
4
5
6
7
Energy Consumption
kWhe per kilotonne
of ore mined
600
500
400
300
200
100
0
284
305
1
2
353
3
Unit Energy Cost
$ per kWhe
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
0.680
0.186
0.196
1
2
0.372
0.386
3
4
0.415
5
0.466
6
7
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Loading/Excavating Ore
30
The energy costs for loading/excavating ore varied from $10 to $98 per kilotonne of ore
mined. The range of costs and efficiencies is as follows:
Range
High : Low
High : Low
Percent
98 : 10
954
Energy Cost ($/kilotonne of ore mined)
Energy Consumption (kWhe/kilotonne of ore mined)
2 201 : 407
541
Unit Energy Cost ($/kWhe)
0.053 : 0.014
378
Figure 3.14 – Excavating (Ore) Energy Costs
Energy Cost
$ per kilotonne
of ore mined
98
100
80
62
60
40
20
10
17
22
22
2
3
4
29
34
35
5
6
7
0
1
8
9
Energy Consumption
kWhe per kilotonne
of ore mined
2 500
2 201
2 000
1 658
1 500
1 000
500
407
461
621
1
2
3
726
857
938 1 061
4
5
6
0
7
8
9
Unit Energy Cost
$ per kWhe
0.06
0.05
0.04
0.03
0.02
0.01
0.00
0.053
0.045 0.047
0.033
0.037 0.037 0.037
0.026
0.014
1
2
3
4
5
6
7
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
8
9
RESULTS: BENCHMARKING PARTICIPATING MINES
Ore Transport
The energy costs for hauling ore to the crusher or stockpile varied from $50 to $162 per
kilotonne of ore mined. The range of costs and efficiencies is as follows:
Range
High : Low
High : Low
Percent
162 : 50
327
Energy Consumption (kWhe/kilotonne of ore mined)
4 432 : 2 020
219
Unit Energy Cost ($/kWhe)
0.045 : 0.021
208
Energy Cost ($/kilotonne of ore mined)
31
Figure 3.15 – Ore Transport Energy Costs
Energy Cost
$ per kilotonne
of ore mined
200
162
150
100
50
88
89
3
4
120
121
5
6
135
135
7
8
63
50
0
1
2
9
Energy Consumption
kWhe per kilotonne
of ore mined
5 000
3 933 4 106
4 000
3 000
2 000
4 432
3 417
2 359
2 020 2 231 2 316
2 687
1 000
0
1
2
3
4
5
6
7
8
9
Unit Energy Cost
$ per kWhe
0.05
0.045
0.037 0.037
0.034 0.035
0.031 0.033
0.04
0.040
0.03
0.021
0.02
0.01
0.00
1
2
3
4
5
6
7
8
9
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Mine Dewatering
32
The energy costs for mine dewatering varied from $0.00 to $454.00 per kilotonne of ore
mined. The range of costs and efficiencies is as follows:
Range
High : Low
Energy Cost ($/kilotonne of ore mined)
454.00 : 0.00
High : Low
Percent
n/a
Energy Consumption (kWhe/kilotonne of ore mined)
4 920 : 0
n/a
Unit Energy Cost ($/kWhe)
0.092 : 0.000
n/a
Figure 3.16 – Mine Dewatering Energy Costs
Energy Cost
$ per kilotonne
of ore mined
500
454.00
400
300
200
100
0
0.00
0.99
1.02
5.00
6.00
12.00
1
2
3
4
5
6
7
Energy Consumption
kWhe per kilotonne
of ore mined
4 920
5 000
4 000
3 000
2 000
1 000
0
0
73
131
247
301
414
1
2
3
4
5
6
7
Unit Energy Cost
$ per kWhe
0.10
0.083
0.092
0.08
0.06
0.04
0.02
0.00
0.000
0.002
0.004
1
2
3
0.039
0.039
4
5
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
6
7
RESULTS: BENCHMARKING PARTICIPATING MINES
Mine Support Equipment and Services
This category includes energy consumption reported by participants for mine support
equipment, road maintenance and service equipment and facilities. The energy costs for various
mine support equipment and services ranged from $12 to $280 per kilotonne of ore mined.
The range of costs and efficiencies is as follows:
Range
High : Low
Energy Cost ($/kilotonne of ore mined)
33
High : Low
Percent
280 : 12
2 376
Energy Consumption (kWhe/kilotonne of ore mined)
6 463 : 549
1 177
Unit Energy Cost ($/kWhe)
0.048 : 0.017
288
Figure 3.17 – Mine Support Equipment and Services Energy Costs
Energy Cost
$ per kilotonne
of ore mined
300
250
200
150
100
50
0
280
12
29
1
2
46
46
56
3
4
5
70
86
97
6
7
8
9
Energy Consumption
kWhe per kilotonne
of ore mined
8 000
7 000
6 000
5 000
4 000
3 000
2 000
1 000
0
6 463
3 365
549
689
1
2
1 815 2 014
1 211 1 347
3
4
5
6
2 408
7
8
9
Unit Energy Cost
$ per kWhe
0.05
0.043 0.043
0.04
0.029
0.03
0.02
0.017
0.034
0.047 0.048
0.038
0.021
0.01
0.00
1
2
3
4
5
6
7
8
9
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
3.3.4 Comparisons Based on Total Material Removed
34
Drilling
The drilling energy costs varied from $0.13 to $29.00 per kilotonne of material removed
(ore plus waste rock) for seven drilling operations, as illustrated below. The range of costs
and efficiencies is as follows:
Energy Cost ($/kilotonne of material removed)
Range
High : Low
High : Low
Percent
29.00 : 0.13
21 969
641 : 55
1 173
0.045 : 0.002
1 858
Energy Consumption (kWhe/kilotonne of material removed)
Unit Energy Cost ($/kWhe)
Figure 3.18 – Drilling Energy Costs
Energy Cost
$ per kilotonne of
material removed
30
25
20
15
10
5
0
29.00
24.00
10.00
0.13
1
7.00
7.00
3
4
2.00
2
5
6
7
Energy Consumption
kWhe per kilotonne
of material removed
800
700
600
500
400
300
200
100
0
598
641
468
281
184
217
2
3
4
5
6
0.039
0.040
0.034
0.037
3
4
5
6
55
1
7
Unit Energy Cost
$ per kWhe
0.05
0.045
0.04
0.03
0.02
0.01
0.002
0.004
1
2
0.00
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
7
RESULTS: BENCHMARKING PARTICIPATING MINES
The influence of the size of the mining operation on energy consumption in drilling activities
is explored in the figure below. There appears to be a very strong relationship between the
drilling energy per kilotonne of material removed (i.e. rock broken) and the total volume
of material removed at the mine. The largest operations consume less than one half of
the energy per kilotonne in drilling operations that is reported by the smaller mines in the
study sample.
35
Figure 3.19 – Scale Economies: Drilling
kWhe per kilotonne
750
500
250
0
0
100
Millions of Tonnes of Material Removed
Blasting
The energy costs for blasting varied from $56 to $275 per kilotonne of material removed
(ore plus waste rock). The range of costs and efficiencies is as follows:
Range
High : Low
High : Low
Percent
Energy Cost ($/kilotonne of material removed)
275 : 56
494
Energy Consumption (kWhe/kilotonne of material removed)
662 : 284
233
0.680 : 0.186
366
Unit Energy Cost ($/kWhe)
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Figure 3.20 – Blasting Energy Costs
36
Energy Cost
$ per kilotonne
of material removed
300
250
200
150
100
50
0
275
208
164
183
187
3
4
5
6
486
491
520
4
5
6
97
56
1
2
7
Energy Consumption
kWhe per kilotonne
of material removed
800
700
600
500
400
300
200
100
0
662
284
305
352
1
2
3
7
Unit Energy Cost
$ per kWhe
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
0.680
0.186
1
0.373
0.385
0.415
3
4
5
0.466
0.196
2
6
7
We examined the relationship between the size of the open-pit mining operations and the
price paid for blasting fuels. As indicated in the figure below, the larger operations tend to
be able to leverage their substantial requirements for blasting fuels into lower prices
from suppliers.
Figure 3.21 – Economies of Scale: Purchase Price of Blasting Fuels
$0.80
$ per kWhe
$0.60
$0.40
$0.20
$0.00
0
100
Millions of Tonnes of Material Removed
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
RESULTS: BENCHMARKING PARTICIPATING MINES
Material Loading/Excavating
The energy costs for loading/excavating ore and waste rock varied from $15 to $98 per
kilotonne of material removed. The range of costs and efficiencies is as follows:
Energy Cost ($/kilotonne of material removed)
Range
High : Low
High : Low
Percent
98 : 15
657
Energy Consumption (kWhe/kilotonne of material removed)
2 202 : 389
566
Unit Energy Cost ($/kWhe)
0.053 : 0.015
364
37
Figure 3.22 – Excavating Energy Costs
Energy Cost
$ per kilotonne
of material removed
98
100
80
60
40
20
15
17
18
1
2
3
18
22
4
5
29
35
36
6
7
8
0
9
Energy Consumption
kWhe per kilotonne
of material removed
2 500
2 202
2 000
1 500
969
1 000
500
389
407
455
1
2
3
620
702
4
5
1 018 1 061
0
6
7
8
9
Unit Energy Cost
$ per kWhe
0.06
0.05
0.04
0.03
0.02
0.01
0.00
0.053
0.045 0.047 0.047
0.033
0.037 0.037
0.026
0.015
1
2
3
4
5
6
7
8
9
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
38
The excavating/loading operations at open-pit mines would appear to generate significant
economies of scale. Larger mines are able to deploy extremely large and expensive (electric)
shovels that would not be cost-efficient in smaller mining operations. The figure below
examines the economies of scale reported in loading operations at the nine mines in the study.
Perhaps surprisingly, the energy consumption (kWhe per kilotonne of material removed)
reported for excavating operations is not much higher at the smaller mines participating in
this study.
Figure 3.23 – Economies of Scale: Excavating
kWhe per kilotonne
3 000
2 000
1 000
0
0
150
Millions of Tonnes of Material Removed
Hauling
The energy costs for hauling material from the pit to the crusher, stockpile or dump varied
from $65 to $158 per kilotonne of material removed (ore plus waste rock). The range of
costs and efficiencies is as follows:
Range
High : Low
High : Low
Percent
158 : 65
243
Energy Consumption (kWhe/kilotonne of material removed)
4 591 : 2 359
195
Unit Energy Cost ($/kWhe)
0.045 : 0.021
208
Energy Cost ($/kilotonne of material removed)
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
RESULTS: BENCHMARKING PARTICIPATING MINES
Figure 3.24 – Transport/Hauling Energy Costs
39
Energy Cost
$ per kilotonne
of material removed
200
150
100
65
75
1
2
112
120
4
5
138
147
158
138
6
7
8
9
88
50
0
3
Energy Consumption
kWhe per kilotonne
of material removed
5 000
4 360 4 591
4 000
3 000
2 687
2 359 2 403
3 028 3 175
3 483
3 759
2 000
1 000
0
1
2
3
4
5
6
7
8
9
Unit Energy Cost
$ per kWhe
0.05
0.045
0.04
0.031
0.037 0.037
0.034 0.034 0.035
0.040
0.03
0.021
0.02
0.01
0.00
1
2
3
4
5
6
7
8
9
Hauling is another mining operation that can generate economies of scale since the largest
mines are more able to use very large trucks (over 200 tons). On the basis of the data illustrated in the figure below, however, the larger mines do not appear to be realizing any savings
in energy consumption per kilotonne of material removed compared with the smaller
open-pit mines in the study.
Figure 3.25 – Economies of Scale: Hauling
kWhe per kilotonne
5 000
4 000
3 000
2 000
1 000
0
0
150
Millions of Tonnes of Material Removed
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Mine Dewatering
40
The energy costs for mine dewatering varied from $0.00 to $86.00 per kilotonne of material
removed. The range of costs and efficiencies is as follows:
Energy Cost ($/kilotonne of material removed)
Range
High : Low
High : Low
Percent
86.00 : 0.00
n/a
928 : 0
n/a
Energy Consumption (kWhe/kilotonne of material removed)
Unit Energy Cost ($/kWhe)
0.002 : 0.000
Figure 3.26 – Mine Dewatering Energy Costs
Energy Cost
$ per kilotonne
of material removed
100
86.00
80
60
40
20
0
0.00
0.61
0.98
1.00
3.00
6.00
1
2
3
4
5
6
7
Energy Consumption
kWhe per kilotonne
of material removed
928
1 000
800
600
400
200
0
144
0
34
40
1
2
3
4
236
256
5
6
7
Unit Energy Cost
$ per kWhe
0.092
0.10
0.083
0.08
0.06
0.04
0.02
0.00
0.000
0.002
0.004
1
2
3
0.039
0.039
4
5
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
6
7
n/a
RESULTS: BENCHMARKING PARTICIPATING MINES
Mine Support Equipment and Services2
The energy costs for various mine support equipment and services ranged from $6 to
$44 per kilotonne of material removed. The range of costs and efficiencies is as follows:
Range
High : Low
High : Low
Percent
44 : 6
684
Energy Consumption (kWhe/kilotonne of material removed)
2 078 : 301
691
Unit Energy Cost ($/kWhe)
0.048 : 0.017
288
Energy Cost ($/kilotonne of material removed)
41
Figure 3.27 – Mine Support Equipment and Services Energy Costs
Energy Cost
$ per kilotonne
of material removed
50
40
40
30
20
10
16
16
2
3
25
26
4
5
34
35
6
7
44
6
0
1
8
9
Energy Consumption
kWhe per kilotonne
of material removed
2 500
2 078
2 000
1 500
1 150 1 291
917
1 000
500
301
342
373
1
2
3
527
666
4
5
0
6
7
8
9
Unit Energy Cost
$ per kWhe
0.05
0.043 0.043
0.04
0.034
0.029
0.03
0.02
0.047 0.048
0.038
0.017
0.021
0.01
0.00
1
2
3
4
2 THIS CATEGORY INCLUDES ENERGY CONSUMPTION REPORTED
MAINTENANCE AND SERVICE EQUIPMENT AND FACILITIES.
5
6
BY PARTICIPANTS FOR
7
8
9
MINE SUPPORT EQUIPMENT, ROAD
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Total Mining Costs per Kilotonne Removed
42
The total energy costs for mining operations ranged from $89 to $483 per kilotonne of
material removed. The range of costs and efficiencies is as follows:
Range
High : Low
High : Low
Percent
483 : 89
510
Energy Consumption (kWhe/kilotonne of material removed)
8 035 : 3 231
249
Unit Energy Cost ($/kWhe)
0.074 : 0.022
334
Energy Cost ($/kilotonne of material removed)
Figure 3.28 – Total Mining Costs
Energy Cost
$ per kilotonne
of material removed
500
439
456
483
7
8
9
381
400
312
322
324
3
4
5
300
200
100
89
107
1
2
0
6
Energy Consumption
kWhe per kilotonne
of material removed
10 000
8 035
8 000
6 581
5 924 5 982 6 108 6 161 6 441
6 000
4 000
3 231
4 030
2 000
0
1
2
3
4
5
6
7
8
9
Unit Energy Cost
$ per kWhe
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0.00
0.054
0.048 0.052
0.060 0.062
0.069
0.074
0.033
0.022
1
2
3
4
5
6
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
7
8
9
RESULTS: BENCHMARKING PARTICIPATING MINES
The effect of economies of scale on the energy consumption in total mining operations
within the nine mines in the study is shown in the figure below. The two largest operations, the oil sands operations, which have no drilling or blasting operations, recorded the
lowest energy consumption per kilotonne of material removed. There was, however, little
evidence of any economies of scale for energy consumption among the seven “hard rock”
open-pit mines in the study.
43
Figure 3.29 – Economies of Scale: Total Mining Energy
kWhe per kilotonne
9 000
6 000
3 000
0
0
150
Millions of Tonnes of Material Removed
3.4 Inter-Mine Comparative Energy Costs –
Mill/Concentrator Operations
3.4.1 Total Mill/Concentrator Operations
The total energy costs for open-pit mining for seven operations are shown below. As illustrated, the energy costs vary from $105 per kilotonne of ore processed to $2,367 per kilotonne.
The range of costs and efficiencies is as follows:
Range
High : Low
Energy Cost ($/kilotonne of ore processed)
Energy Consumption (kWhe/kilotonne of ore processed)
Unit Energy Cost ($/kWhe)
2 367 : 105
35 701 : 13 144
0.083 : 0.005
High : Low
Percent
2 254
272
1 681
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
44
The total costs shown here cover crushing, grinding, all other concentration, extraction
and recovery operations, tailings treatment, process water supply, and other plant energy.
Any in-pit crushing has been included with the primary crushing operations at the mill.
Figure 3.30 – Total Energy Costs: Mill/Concentrator Operations
Energy Cost
$ per kilotonne
of ore processed
2 367
2 500
2 000
1 523
1 500
1 209
960
1 000
500
353
431
2
3
105
0
1
4
5
6
7
Energy Consumption
kWhe per kilotonne
of ore processed
40 000
35 000
30 000
25 000
20 000
15 000
10 000
5 000
0
35 701
21 229
21 298
2
3
23 811
24 540
4
5
28 449
13 144
1
6
7
Unit Energy Cost
$ per kWhe
0.10
0.083
0.08
0.072
0.06
0.051
0.04
0.02
0.033
0.005
0.010
1
2
0.039
0.00
3
4
5
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
6
7
RESULTS: BENCHMARKING PARTICIPATING MINES
3.4.2 Mill/Concentrator Operations – Stages of Production
45
Crushing
Energy costs for crushing ore varied from $2 to $160 per kilotonne of ore processed for
seven operations. The range of costs and efficiencies is as follows:
Range
High : Low
Energy Cost ($/kilotonne of ore processed)
High : Low
Percent
160 : 2
8 126
Energy Consumption (kWhe/kilotonne of ore processed)
2 804 : 253
1 110
Unit Energy Cost ($/kWhe)
0.092 : 0.003
2 957
Figure 3.31 – Crushing Energy Costs
Energy Cost
$ per kilotonne
of ore processed
200
160
150
100
50
2
0
39
46
3
4
60
79
3
1
2
5
6
7
Energy Consumption
kWhe per kilotonne
of ore processed
3 000
2 500
2 000
1 500
1 000
500
0
2 804
2 358
1 945
1 065
253
1
427
561
2
3
4
5
6
7
Unit Energy Cost
$ per kWhe
0.10
0.083
0.092
0.08
0.057
0.06
0.041
0.04
0.02
0.025
0.003
0.008
0.00
1
2
3
4
5
6
7
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Grinding
46
Energy costs for grinding ore varied from $6 to $1,507 per kilotonne of ore processed.
The range of costs and efficiencies is as follows:
Range
High : Low
Energy Cost ($/kilotonne of ore processed)
1 507 : 6
Energy Consumption (kWhe/kilotonne of ore processed)
23 815
16 320 : 2 639
619
0.092 : 0.002
3 849
Unit Energy Cost ($/kWhe)
Figure 3.32 – Grinding Energy Costs
Energy Cost
$ per kilotonne
of ore processed
2 000
1 507
1 500
1 000
582
603
698
4
5
6
500
0
6
21
1
2
139
3
7
Energy Consumption
kWhe per kilotonne
of ore processed
20 000
14 930
15 000
5 000
16 320
12 232
10 000
7 280
2 639
3 620
1
2
4 957
0
3
4
5
6
7
Unit Energy Cost
$ per kWhe
0.10
0.083
0.092
0.08
0.057
0.06
0.04
0.02
0.002
0.004
1
2
0.039
0.039
3
4
High : Low
Percent
0.00
5
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
6
7
RESULTS: BENCHMARKING PARTICIPATING MINES
Crushing and Grinding Combined
Energy costs for crushing and grinding combined varied from $10 to $1,547 per kilotonne
of ore processed. The range of costs and efficiencies is as follows:
Range
High : Low
Energy Cost ($/kilotonne of ore processed)
1 547 : 10
Energy Consumption (kWhe/kilotonne of ore processed)
High : Low
Percent
16 014
16 874 : 3 704
456
0.092 : 0.003
3 539
Unit Energy Cost ($/kWhe)
47
Figure 3.33 – Crushing and Grinding Energy Costs
Energy Cost
$ per kilotonne
of ore processed
2 000
1 547
1 500
859
1 000
500
0
10
23
1
2
649
661
4
5
199
3
6
7
Energy Consumption
kWhe per kilotonne
of ore processed
20 000
15 035
15 000
10 000
5 000
16 747 16 874
7 842
3 704
5 210
5 978
2
3
0
1
4
5
6
7
Unit Energy Cost
$ per kWhe
0.10
0.083
0.092
0.08
0.057
0.06
0.04
0.02
0.003
0.005
1
2
0.033
0.039
3
4
0.00
5
6
7
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
All Other Mill/Concentrator
48
This category of mill/concentrator costs aggregates energy consumed in the separation,
filtering and drying processes for iron ore mines, and included in the separation are
carbon-in-leach (CIL) and carbon-in-column (CIC) circuits, stripping, electrowinning and
refining operations at gold mines. These costs varied from $45 to $753 per kilotonne of
ore processed. The range of costs and efficiencies is as follows:
Range
High : Low
Energy Cost ($/kilotonne of ore processed)
753 : 45
Energy Consumption (kWhe/kilotonne of ore processed)
951
0.070 : 0.005
1 334
Figure 3.34 – Energy Costs: All Other Processing
Energy Cost
800
700
600
500
400
300
200
100
0
753
623
327
45
1
107
129
170
2
3
4
5
6
7
Energy Consumption
kWhe per kilotonne
of ore processed
30 000
25 000
20 000
15 000
10 000
5 000
0
26 105
8 666
2 744
4 480
4 650
1
2
3
4
9 331
5
10 827
6
7
0.067
0.070
6
7
Unit Energy Cost
$ per kWhe
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0.00
0.029
0.037
0.039
0.013
0.005
1
2
3
4
1 668
26 105 : 2 744
Unit Energy Cost ($/kWhe)
$ per kilotonne
of ore processed
High : Low
Percent
5
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
RESULTS: BENCHMARKING PARTICIPATING MINES
Tailings Treatment
Energy costs for tailings treatment varied from $5 to $100 per kilotonne of ore processed.
The range of costs and efficiencies is as follows:
Range
High : Low
Energy Cost ($/kilotonne of ore processed)
100 : 5
49
High : Low
Percent
1 844
Energy Consumption (kWhe/kilotonne of ore processed)
2 261 : 245
Unit Energy Cost ($/kWhe)
0.092 : 0.002
924
3 849
Figure 3.35 – Energy Costs: Tailings Treatment
Energy Cost
$ per kilotonne
of ore processed
100
100
85
80
60
49
40
20
58
23
5
9
1
2
0
3
4
5
6
7
Energy Consumption
kWhe per kilotonne
of ore processed
2 500
2 049
2 000
2 261
1 751
1 500
1 023
1 261
1 503
1 000
500
245
0
1
2
3
4
5
6
7
Unit Energy Cost
$ per kWhe
0.10
0.083
0.092
0.08
0.057
0.06
0.04
0.02
0.002
0.004
1
2
0.039
0.039
3
4
0.00
5
6
7
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
Process Water Supply
50
Energy costs for process water supply varied from $5 to $90 per kilotonne of ore processed.
The range of costs and efficiencies is as follows:
Range
High : Low
High : Low
Percent
90 : 5
1 671
Energy Cost ($/kilotonne of ore processed)
Energy Consumption (kWhe/kilotonne of ore processed)
2 249 : 79
2 864
Unit Energy Cost ($/kWhe)
0.092 : 0.002
3 849
Figure 3.36 – Process Water Supply Energy Costs
Energy Cost
$ per kilotonne
of ore processed
100
90
80
60
46
40
20
30
20
5
7
8
0
1
2
3
4
5
6
7
Energy Consumption
kWhe per kilotonne
of ore processed
2 500
2 249
1 978
2 000
1 500
1 089
1 182
4
5
1 000
500
518
523
2
3
79
0
1
6
7
Unit Energy Cost
$ per kWhe
0.10
0.083
0.092
0.08
0.057
0.06
0.04
0.02
0.002
0.004
1
2
0.039
0.039
3
4
0.00
5
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
6
7
RESULTS: BENCHMARKING PARTICIPATING MINES
Other Plant Energy
Other plant energy costs varied from $5 to $123 per kilotonne of ore processed. The range
of costs and efficiencies is as follows:
Range
High : Low
Energy Cost ($/kilotonne of ore processed)
123 : 5
51
High : Low
Percent
2 254
Energy Consumption (kWhe/kilotonne of ore processed)
3 326 : 552
Unit Energy Cost ($/kWhe)
0.069 : 0.004
603
1 745
Figure 3.37 – Other Plant Energy Costs
Energy Cost
$ per kilotonne
of ore processed
150
123
120
90
76
60
30
38
51
20
5
0
1
2
3
4
5
6
3 143
3 326
5
6
Energy Consumption
kWhe per kilotonne
of ore processed
3 500
3 000
2 500
2 000
1 500
1 000
500
0
1 852
2 013
3
4
1 382
552
1
2
Unit Energy Cost
$ per kWhe
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0.00
0.069
0.038
0.039
4
5
0.027
0.004
0.006
1
2
3
6
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
3
3 RESULTS: BENCHMARKING PARTICIPATING MINES
3.5 General and Administrative
52
The total energy costs for general and administrative operations for seven operations are
shown below. As illustrated, the reported energy costs vary from $1 per kilotonne of ore
mined to $153 per kilotonne. The range of costs and efficiencies is as follows:
Range
High : Low
Energy Cost ($/kilotonne of ore mined)
High : Low
Percent
153 : 1
15 504
Energy Consumption (kWhe/kilotonne of ore mined)
4 818 : 83
5 819
Unit Energy Cost ($/kWhe)
0.059 : 0.004
1 503
The total costs shown here cover energy consumed in operating guardhouses, parking lots,
assay laboratories, camps, etc.
Figure 3.38 – General and Administrative Energy Costs
Energy Cost
$ per kilotonne
of ore mined
200
153
150
100
74
50
0
1
1
5
2
7
3
17
4
30
5
6
7
Energy Consumption
kWhe per kilotonne
of ore mined
4 818
5 000
4 000
3 000
1 877
2 000
1 236
1 000
83
252
451
503
1
2
3
4
0
5
6
7
Unit Energy Cost
$ per kWhe
0.06
0.05
0.04
0.03
0.02
0.01
0.00
0.055
0.039
0.039
4
5
0.059
0.032
0.004
0.006
1
2
3
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
6
7
4
POTENTIAL
SAVINGS:
ACHIEVING
BENCHMARK
STANDARDS
4 POTENTIAL SAVINGS: ACHIEVING BENCHMARK STANDARDS
4. POTENTIAL SAVINGS: ACHIEVING BENCHMARK STANDARDS
54
4.1 Context
In this section, we present some general estimates of potential energy savings from attaining
the performance of the most energy-efficient operations. To determine the related potential
cost savings, we used weighted average costs for each source of energy.
It should be noted, however, that the potential savings identified may not be realizable for
a number of practical reasons. For example, savings may be related to economies of scale
or the nature of the ore body, or customer requirements may dictate the use of a particular
technology precluding the use of a more energy-efficient technology.
At the same time, there may be some offsetting arguments regarding the size of the potential
savings when considering the following:
• There are opportunities for improvement in the lowest-cost, most efficient facilities. The
fact that different firms lead in different stages of production provides even more evidence
of the potential.
• There could be operations outside the study sample that have lower-cost, more efficient
operations.
In light of the above observations, we present below a simplistic estimate of the potential
savings achievable if each participant were to attain the most efficient level of energy consumption for each stage of production, using average energy source prices.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
POTENTIAL SAVINGS: ACHIEVING BENCHMARK STANDARDS
4.2 Potential Energy Savings: Mining
55
Mining Operations (Material Removed)
Weighted
Average
kWhe
Lowest
kWhe/kt
Savings
kWhe/kt
Average
$/kWhe
Total
kt
Total
Savings
($M)
Drilling
291
55
236
0.031
326
2.4
Blasting
448
284
104
0.034
326
18.2
Loading
707
389
318
0.036
533
6.1
3 258
2 359
899
0.033
533
15.8
704
301
403
0.032
533
6.9
Transport
Support
Total
49.4
(36%)
With respect to mining operations, potential identified energy savings represent a cost saving
of about $49 million, or approximately 36 percent.
4.3 Potential Energy Savings: Milling
Iron Ore Concentration
Weighted
Average
kWhe
Lowest
kWhe/kt
Savings
kWhe/kt
Average
$/kWhe
Total
kt
Total
Savings
($M)
Crushing
1 282
253
1 029
0.021
95 018
2.0
Grinding
3 983
2 639
1 344
0.017
95 018
2.2
10 008
4 480
5 528
0.013
95 018
6.8
Tailings
1 857
1 503
354
0.015
95 018
0.5
Process Water
1 692
1 182
510
0.014
95 018
0.7
Other
2 730
1 382
1 348
0.006
55 101
0.4
Further
Processing
Total
12.7
(47%)
With respect to iron ore concentration operations, potential energy savings identified are
about $13 million, or approximately 47 percent.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES
4
4 POTENTIAL SAVINGS: ACHIEVING BENCHMARK STANDARDS
Gold Milling
56
Weighted
Average
kWhe
Lowest
kWhe/kt
Savings
kWhe/kt
Average
$/kWhe
Total
kt
Total
Savings
($M)
Crushing
1 549
427
1 122
0.054
15 783
1.0
Grinding
13 009
7 280
5 729
0.063
15 783
5.7
Further
Processing
6 248
2 744
3 504
0.058
15 783
3.2
Tailings
1 131
245
886
0.057
15 783
0.8
538
79
459
0.063
15 783
0.5
2 029
552
1 477
0.038
15 783
0.9
Process Water
Other
Total
11.9
(53%)
With respect to gold milling operations, potential energy savings identified are in the order
of $12 million, or approximately 53 percent.
To sum up, potential annual energy savings identified with the most efficient operation for
each production stage as the benchmark are about $74 million (about one third of total
energy costs), as applied to the nine study participants.
On a cautionary note, we should point out that these savings are hypothetical and may not
be achievable owing to circumstances faced by each mine, i.e. the nature of the ore body,
technology employed, long-term contractual obligations, etc.
BENCHMARKING THE ENERGY CONSUMPTION OF CANADIAN OPEN-PIT MINES