The Energy & Carbon Intensity of Mining: Understanding the ......Presentation Overview •Energy Use in Mining ‘101’ = Carbon Emissions •Current ‘Mega-Trends’ in Mining •these

The Energy & Carbon Intensity of Mining:

Understanding the Growing Importance

of Renewable Energy

Assoc. Prof. Gavin M. Mudd

RMIT University, Melbourne, Australia

… plus Mineral Policy Institute (Australia), World Mine Tailings Failures (USA)

Georgius Agricola (1556) :

“… the strongest argument of the detractors is that the fields are

devastated by mining operations … Also they argue that the woods

and groves are cut down, for there is need of an endless amount of

wood for timbers, machines, and the smelting of metals. And when

the woods and groves are felled, then are exterminated the beasts

and birds, very many of which furnish a pleasant and agreeable food

for man. Further, when the ores are washed, the water which has

been used poisons the brooks and streams, and either destroys the

fish or drives them away. Therefore the inhabitants of these regions,

on account of the devastation of their fields, woods, groves, brooks

and rivers, find great difficulty in procuring the necessaries of life …

Thus it is said, it is clear to all that there is greater detriment from

mining than the value of the metals which the mining produces.”

2Mudd: Energy & Climate Issues in Mining UBA Raw Materials & Environment Conf, Feb. 2019

Presentation Overview

• Energy Use in Mining ‘101’ = Carbon Emissions

• Current ‘Mega-Trends’ in Mining

• these underpin likely energy/carbon intensity

• Life Cycle Assessments of Metal Mining

• Examples & Case Studies

• Growing Need for Renewable Energy

• Metals for Renewable Energy & Batteries

• Summary


Energy Use in Mining ‘101’

• Mining is very simple with its energy needs:

DIESEL & ELECTRICITY

• Diesel is used in haul trucks, excavators,

underground vehicles, on-site power plants

• Electricity is used in ore processing, site

administration buildings, etc.

Really, it’s that simple

• Energy also used to make machines,

chemicals, transport stuff / people, etc …


Energy Intensity in Mining

• There are many factors which can affect the

energy needed to operate a mine:

• ore body depth: deeper = more energy

• Age of a mine: older mines often deeper, longer haul

roads / shafts, sometimes more waste rock at greater

distance to dump, …

• Ore processing configuration: SX-EW v flotation,

especially comminution grind size, scale, …

• Environmental requirements: need for water treatment

(or not), tailings disposal configuration (especially if

paste / thickened tailings are used), etc …


Carbon Issues in Mining

• Carbon emissions derived mostly from direct

diesel use (Scope 1) & indirectly from

electricity (Scope 2) (minor amounts from

explosives, land use change, some chemicals)

• For electricity, carbon intensity is closely

linked to power plant type: coal, gas, diesel,

solar, geothermal, etc …

Put simply, more energy intense mines are

typically more carbon intensive


Key Global Mining MEGA-Trends

• Globally, we have plenty of mineral resources already

know to meet reasonable societal demands for

decades … primary metals, critical metals, etc.

• The real issues are how / what / where / when / why we

mine different commodities … e.g. coal v lithium

• Global mega-trends already affecting mining include:

• continually growing demand (with demand for ‘critical metals’

expected to grow substantially)

• declining ore grades … sometimes declining ore quality

• deeper deposits … variable around the world but still very real

• increasing wastes to manage: tailings & waste rock (& slags)

• growing community, investor & regulatory concerns

• gradually growing chemicals / energy / water inputs


Global Cu Mine Production by Country


0

2

4

6

8

10

12

14

16

18

1900

1910

1920

1930

1940

1950

1960

1970

1980

1990

2000

2010

An

nu

al

Co

pp

er

Pro

du

cti

on

(M

t C

u)

USA

AustraliaCanada

Chile

China

Africa

Re

st

of

the

Wo

rld

Russia-Eastern Block

Declining Ore Grades: Very Real


0

3

6

9

12

15

18

21

24

27

1770 1790 1810 1830 1850 1870 1890 1910 1930 1950 1970 1990 2010

Co

pp

er

Ore

Gra

de

(%

Cu

)

Australia Canada

PNG India

UK Poland

Indonesia Chile

Brazil USA

Laos Sweden

Note: some PNG data(1907-1970) is

greater than 30% Cu.

Ever-Growing Waste Rock Piles …


0

330

660

990

1,320

1,650

1,980

2,310

0

40

80

120

160

200

240

280

1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005

Wa

ste

Ro

ck

(G

old

, B

lac

k C

oa

l)

Wa

ste

Ro

ck

(C

u,

Dia

mo

nd

s, U

, B

row

n C

oa

l)

Copper (Mt) Uranium (Mt)

Diamonds (Mt) Brown Coal (Mm3)

Gold (Mt) Black Coal (Mm3)

(Mm3)

(Mm3)

No Obvious AMD …

BUT pH 3.5

Life Cycle Assessment of Mining

• LCA is a formal methodology to quantify the

inputs & outputs to produce a good or service

• Literature covers most metals reasonably well

• Often the key metrics focussed on are energy,

carbon, water … sometimes toxicity, land use,

but waste rarely (not sure why!)

• One tricky issue is the allocation for multi-

metal mines – typically solved by value• e.g. Cu-Au mine splits energy inputs / carbon outputs based

on respective value of each metal


Theoretical LCA Studies: Cu


0

300

600

900

1,200

1,500

0 0.5 1 1.5 2 2.5 3

En

erg

y I

nte

nsit

y (

GJ/t

Cu

)

Ore Grade (Cu/%)

Concentrate-Smelting (75 µm comminution)


Direct Smelting

Heap Leaching

Pressure Leaching

In Situ Leaching

0

30

60

90

120

150

0 0.5 1 1.5 2 2.5 3

GG

Es I

nte

nsit

y (

t C

O2e/t

Cu

)

Ore Grade (%Cu)



Direct Smelting

Heap Leaching

Pressure Leaching

In Situ Leaching

Norgate-Jahanshahi, 2010, Mins. Eng.

Theoretical LCA Studies: Rare Earths


0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

450,000

0 10 20 30 40 50 60 70 80 90 100

GH

G E

mis

sio

ns

(kg

CO

2e/t

TR

EO)

Cumulative TREO Production Distribution (%)

Tanbreez ZandkopsdriftAshram (Eldor) Olympic DamChina Sichuan Mianning Strange LakeDubbo Zirconia Bayan OboFoxtrot KvanefjeldNechalacho (Thor Lake) Norra KärrTantalus Nolans BoreBrowns Range AraxáZeus (Kipawa Lake) NguallaBokan Dotson Bear LodgeSteenkampskraal BucktonChina Southern Seven Provinces (Type B) Eco RidgeRound Top China Southern Seven Provinces (Type A)Songwe Hill

Ch

ina

Ion

ic C

lay

(B)

Bayan Obo

Monazite XenotimeLujavriteIonic Clay

Allanite Apatite Bastnäsite Eudialyte

Ch

ina

Ion

ic C

lay

(A)

Kvanefjeld

Araxá

Bea

r Lo

dge

Songwe Hill

No

lan

s B

ore

Bro

wn

s R

ange

Sustainability Reporting: Real LCA Data


Source: WMC

Sustainability Reporting: Real LCA Data


Source: Anglo Platinum

Case Study: LCA of Copper Mining


y = 1.5548x-0.606

R² = 0.28

0

2

4

6

8

10

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

GH

G I

nte

nsi

ty (

t C

O2e/

t C

u)

Ore Grade (% Cu)

Mine + Leaching, SX-EW (LSE)

Mine + Concentrator

Mine + Conc. + LSE

Mine + Conc. + Smelter

Mine + Conc. + Smelter + Refinery ± LSE

Mine + Concentrator

Case Study: LCA of Gold Mining


y = 27.92x-0.604

R² = 0.3328

y = 17.726x-0.382

R² = 0.5243

y = 7.9054x-0.516

R² = 0.4344

0

10

20

30

40

50

0 10 20 30 40 50 60

Un

it G

ree

nh

ou

se

Em

iss

ion

s (

t C

O2/k

g A

u)

Ore Grade (g/t Au)

Coal

Diesel

Gas

Hydro

Coal/Hydro

Diesel/Geothermal

Gas/Hydro

Hydro/Coal

Hydro - (0.72, 81.2)Coal - (5.3, 59.57)

Hydro -(77.1, 0.2), (82.39, 0.2)

Coal

Hydro

Diesel

Case Study: LCA of Gold Mining


0

10

20

30

40

50

60

70

0 110 220 330 440 550 660

Un

it G

ree

nh

ou

se

Em

iss

ion

s (

t C

O2/k

g A

u)

Unit Energy Consumption (GJ/kg Au)

Coal Diesel

Gas Hydro

Coal/Hydro Diesel/Geothermal

Gas/Hydro Hydro/Coal

Points excluded:(301.1, 95.01) and(288.9, 117.47)

Case Study: LCA of Nickel Mining


0

10

20

30

40

50

0 100 200 300 400 500 600 700

t C

O2e

/ t

Ni±

Cu

±C

o

GJ / t Ni±Cu±Co

Inco Sudbury Thompson

Murrin Murrin Sorowako

WMC Total Yabulu

Xstrata Canada Cerro Matoso

Laterite ProjectsSulfide Projects

0

12

24

36

48

60

72

0

1

2

3

4

5

6

1991 1993 1995 1997 1999 2001 2003 2005

En

erg

y I

nte

ns

ity (

GJ

/t N

i)

Em

iss

ion

s In

ten

sit

y (

t S

O2/t

Ni;

t C

O2/t

Ni)

Sulfur Dioxide (t SO2/t Ni)

Energy Intensity(GJ/t Ni)

Greenhouse Gases(t CO2/t Ni)

Global Nickel Mines Kalgoorlie Nickel Smelter

LCA of Mining in Papua New Guinea


0

0.5

1

1.5

2

2.5

3

1996 2000 2004 2008 2012 2016

En

erg

y I

nte

nsit

y (

GJ/t

ore

)

Ok TediMisima

Porgera

Lihir

Hidden

Valley

(a)

Simberi

0

17

34

51

68

85

102

1996 2000 2004 2008 2012 2016

Ele

ctr

ical

Inte

nsit

y (

kW

h/t

ore

)

Ok Tedi

Misima

Porgera

Hidden

Valley

(b)

Lihir

0

0.3

0.6

0.9

1.2

1.5

1.8

1996 2000 2004 2008 2012 2016D

iesel

Inte

nsit

y (

L/t

ro

ck)

Ok

Tedi

Misima

Porgera

Lihir

(c)

Hidden

Valley

0

20

40

60

80

100

120

140

1996 2000 2004 2008 2012 2016

Carb

on

In

ten

sit

y (

t C

O2/t

ore

)

Ok Tedi

Misima

Porgera

Lihir

Hidden

Valley

(a)

Simberi

0

6

12

18

24

30

36

1996 2000 2004 2008 2012 2016

Carb

on

In

ten

sit

y

Ok Tedi (t CO2/t Cu)

MisimaPorgera

Lihir

Hidden

Valley

Au mines(t CO2/kg Au)

(b)

Simberi

Growing Need for Renewable Energy

• Mining is only just beginning to explore the full

potential of renewable energy technologies as well as

shifting to electric vehicles

• Goldcorp’s enw Borden Lake Au mine is now fully

electric … a remarkable step change

• Chilean mines are building 100’s MW of solar panel

farms … in contrast Australia is minimal

• Australia’s former Kidston Au mine is now being

transformed into a solar-wind-pumped hydro project

• PNG’s Lihir mine extracts energy from geothermal

activity related to the geology of the mine … although

initially it ignored this resource


Energy …

Oz Style

Energy in Australia 2012BREE for RET

Sandfire’s Solar Farm at DeGrussa (WA)


Geothermal Energy at Lihir (PNG)


Metals for Renewable Energy & Batteries

• There is widespread concern about the ability to meet the rapidly

growing demand for metals and minerals used to make energy

storage batteries and various renewable energy technologies

• e.g. batteries need lithium, nickel, cobalt, graphite, … future V? Zn? Na?

• Renewable energy can use Te, In, Cd, Ga, … plus common metals

• There is often confused concern about resource depletion versus

concentration of supply: these are not the same thing !

• Based on known resources – we have absolutely plenty of

deposits already known to continue the roll-out of renewable

energy & batteries to meet current climate targets (e.g. Paris

Agreement) or even more ambitious targets

• There remain real issues of supply concentration, as well as

resource concentration … but these can be addressed in

numerous ways by governments, industry and community


Summary: Energy & Carbon vs Mining

• The energy & carbon intensity of mining will continue

to grow … often despite efforts to be more efficient or

deploy new technology

• declining ore grades are crucial in this regard

• Critical to understand the energy-carbon drivers for

each mine site – every mine can be quite different

(sometimes surprisingly so)

• Growing reliability of sustainability reporting is

providing extensive data which can be used to

understand energy-carbon intensity of mining

• Mining is crucial to supply the metals required for

renewable energy & energy storage batteries


Acknowledgements

• UBA for supporting my participation

• Peter Diehl (WISE Uranium Project)

• Special thanks to former PhD students Zhehan Weng, Stephen

Northey, Tim Werner

• Funding support from CSIRO over the years

• The many communities I’ve visited who live with mines (& their

companies & governments) in all sorts of creative ways !


Documents

The Energy & Carbon Intensity of Mining: Understanding the ......Presentation Overview •Energy Use in Mining ‘101’ = Carbon Emissions •Current ‘Mega-Trends’ in Mining •these