Dr Gavin M Mudd Institute for Sustainable Water Resources (Civil Eng)

www-civil.eng.monash.edu.au

Dr Gavin M MuddInstitute for Sustainable Water Resources (Civil Eng)

Sustainable Mining :Sustainable Mining :An Evaluation of Changing Ore An Evaluation of Changing Ore Grades and Waste VolumesGrades and Waste Volumes

Sustainable Mining : Ore Grades & Waste Volumes / 2

Agricola (1556) :Agricola (1556) :

“… “… the strongest argument of the detractors is that the the strongest argument of the detractors is that the fields are fields are devastated by mining operationsdevastated by mining operations … Also they argue that the … Also they argue that the woods and groves are cut downwoods and groves are cut down, for there is need of an endless , for there is need of an endless amount of wood for timbers, machines, and the smelting of metals. amount of wood for timbers, machines, and the smelting of metals. And when the woods and groves are felled, then are exterminated And when the woods and groves are felled, then are exterminated the beasts and birds, very many of which furnish a pleasant and the beasts and birds, very many of which furnish a pleasant and agreeable food for man. Further, when the ores are washed, agreeable food for man. Further, when the ores are washed, the the water which has been used poisons the brooks and streamswater which has been used poisons the brooks and streams, and , and either destroys the fish or drives them away. Therefore the either destroys the fish or drives them away. Therefore the inhabitants of these regions, on account of the devastation of their inhabitants of these regions, on account of the devastation of their fields, woods, groves, brooks and rivers, find great difficulty in fields, woods, groves, brooks and rivers, find great difficulty in procuring the necessaries of life … Thus it is said, it is clear to all procuring the necessaries of life … Thus it is said, it is clear to all that that there is greater detriment from mining than the value of the there is greater detriment from mining than the value of the metals which the mining producesmetals which the mining produces.”.”


From Tasmania to WA and beyond :From Tasmania to WA and beyond :


Sustainable Mining Sustainable Mining ??

• Debate about the impact of mining is Debate about the impact of mining is old indeed : old indeed : debate is healthydebate is healthy

• There is now renewed debate about, There is now renewed debate about, termed “sustainable mining”termed “sustainable mining”

• But what is this concept ?But what is this concept ?

Need to look at history of mining and Need to look at history of mining and mineral productionmineral production


Presentation OutlinePresentation Outline

• Mining and milling ‘101’Mining and milling ‘101’

• Data : From production to sustainabilityData : From production to sustainability

• Mining industry positionMining industry position

• Trends in Australian mineral productionTrends in Australian mineral production

• Future directions & needsFuture directions & needs


Mining & Milling ‘101’Mining & Milling ‘101’

• Essentially, ore with the mineral of Essentially, ore with the mineral of interest is excavated from the earth, interest is excavated from the earth, processed, refined and ‘consumed’processed, refined and ‘consumed’

• Ore grades vary widely, Ore grades vary widely, eg.eg. : :Gold Gold ~2 g/t~2 g/t IronIron ~60%~60% Copper ~2%Copper ~2%

• Excavation may be underground or open Excavation may be underground or open cutcut

• ‘‘Solution Mining’ is also usedSolution Mining’ is also used (small though) (small though)


Mining-Milling PictorialMining-Milling Pictorial


Data : From Production to SustainabilityData : From Production to Sustainability

• To assess the production performance of a To assess the production performance of a mine plus the sustainability of the mining mine plus the sustainability of the mining industry, various data needs include :industry, various data needs include :

– mining data, esp. %open cut v undergroundmining data, esp. %open cut v underground> MUSTMUST include waste rock (AMD ?) include waste rock (AMD ?)

– ore milled (recovery?) – impurities (ore milled (recovery?) – impurities (AsAs, , HgHg?)?)

– water & energy use & managementwater & energy use & management

– extent & extent & successsuccess of rehabilitation of rehabilitation

– emissions (eg. greenhouse gases)emissions (eg. greenhouse gases)

• Most of this data is Most of this data is alreadyalready collected collected


Mining Industry :Mining Industry :Reporting & SustainabilityReporting & Sustainability

• In Australia, the mining industry now has a In Australia, the mining industry now has a voluntary code for environmental mattersvoluntary code for environmental matters

• Many companies now publish annual Many companies now publish annual environment reports under this code environment reports under this code (increasingly including social issues)(increasingly including social issues)

• Globally, as part of the 2002 WSSD, the Globally, as part of the 2002 WSSD, the mining industry published the mining industry published the ‘Minerals ‘Minerals Mining & Sustainable Development’Mining & Sustainable Development’ (or (or MMSD) reports – acknowledging many MMSD) reports – acknowledging many major issues facing the industrymajor issues facing the industry


Mining : Mining : SomeSome Key Issues Key Issues

• Some of the major issues facing the Some of the major issues facing the future of mining include :future of mining include :– Declining ore gradesDeclining ore grades– Increasing waste rock / tailings volumesIncreasing waste rock / tailings volumes– Resources versus depletionResources versus depletion– Land use / conservationLand use / conservation– Extrapolating rehabilitation performanceExtrapolating rehabilitation performance

• These and other issues all affect the These and other issues all affect the overall sustainability of miningoverall sustainability of mining


• To assess the trends in ore grades To assess the trends in ore grades and waste rock, a detailed compilation and waste rock, a detailed compilation of mineral production in Australia was of mineral production in Australia was undertaken, including :undertaken, including :– Ore milledOre milled –– Ore grade Ore grade

– ProductionProduction –– Waste rock Waste rock

– Open cut v underground miningOpen cut v underground mining

Australian Mining Industry :Australian Mining Industry :Compiling the Production HistoryCompiling the Production History


Minerals-Metals Production in AustraliaMinerals-Metals Production in Australia

0

400

800

1,200

1,600

2,000

1845 1860 1875 1890 1905 1920 1935 1950 1965 1980 1995

An

nu

al P

rod

uct

ion

Copper (kt)

Gold (t)

Lead (kt)

Manganese (kt)

Nickel (kt)

Silver (t)

Zinc (kt)

Silver

Manganese

Gold

Lead

Zinc

Copper

Nickel


Minerals-Metals Production in AustraliaMinerals-Metals Production in Australia

0

25

50

75

100

125

150

175

1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

An

nu

al P

rod

uct

ion

: B

auxi

te, A

lum

ina,

Dia

mo

nd

s, Ir

on

Ore

0

2

4

6

8

10

12

14

An

nu

al P

rod

uct

ion

: U

ran

ium

, Tin

Bauxite (Mt)

Alumina (Mt)

Diamonds (Mcarats)

Iron Ore (Mt)

Tin (kt)

Uranium (kt U3O8)

TinIron Ore

Alumina

Uranium

Bauxite

Diamonds


Coal Production in AustraliaCoal Production in Australia

0

60

120

180

240

300

360

1828 1840 1852 1864 1876 1888 1900 1912 1924 1936 1948 1960 1972 1984 1996

An

nu

al R

aw C

oal

Pro

du

ctio

n (

Mt)

0

2.5

5

7.5

10

12.5

15

Bro

wn

Co

al O

verb

urd

en (

Mm

3 )

Black Coal Brown Coal

Brown Coal Overburden


Coal Production : OC v UG, cumulativeCoal Production : OC v UG, cumulative

0

10

20

30

40

50

60

70

80

90

1940 1950 1960 1970 1980 1990 2000

Pro

po

rtio

n D

eriv

ed b

y O

pen

Cu

t M

ines

(%

)

Black Coal (only)

Black & Brown Coal

0

1.5

3

4.5

6

7.5

9

1825 1850 1875 1900 1925 1950 1975 2000

Cu

mu

lati

ve B

lack

& B

row

n C

oal

Pro

du

ctio

n (

Gt)


Gold Mining & MillingGold Mining & Milling

0

60

120

180

240

300

1850 1870 1890 1910 1930 1950 1970 1990

Go

ld O

re M

illed

& W

aste

Ro

ck (

Mt)

0

9

18

27

36

45

Go

ld G

rad

e (g

/t)

/ Was

te R

ock

as

%A

u

Ore Milled

Waste Rock

Average Grade

Waste Rock as % kg Au


Copper Mining & MillingCopper Mining & Milling

0

20

40

60

80

100

120

1844 1864 1884 1904 1924 1944 1964 1984 2004

Co

pp

er O

re M

illed

& W

aste

Ro

ck (

Mt)

/ %

Op

en C

ut

/ Was

te a

s %

t C

u

0

6

12

18

24

30

36

Co

pp

er G

rad

e (%

Cu

)

Ore Milled

Waste Rock

%Open Cut

Waste Rock as % t Cu

Average Grade


Lead-Zinc-Silver Mining & MillingLead-Zinc-Silver Mining & Milling

0

5

10

15

20

25

1880 1900 1920 1940 1960 1980 2000

Lea

d-Z

inc-

Silv

er O

re M

illed

(M

t) /

%O

pen

Cu

t

0

270

540

810

1080

1350

Silv

er G

rad

e (g

/t)

Ore Milled

Average Lead Grade

Average Zinc Grade

%Open Cut

Average Silver Grade


Data Gaps & Future Directions :Data Gaps & Future Directions :Towards Sustainable MiningTowards Sustainable Mining

• Some mining companies do report wide-Some mining companies do report wide-ranging mining-milling data - ranging mining-milling data - many do notmany do not

• To be meaningful, all relevant data should To be meaningful, all relevant data should be publicly reported by mining companies be publicly reported by mining companies and collated on an industry basisand collated on an industry basis

• The “environmental burden” of modern The “environmental burden” of modern mining is increasing per unit of productionmining is increasing per unit of production

• Mining’s “sustainability” – depends on Mining’s “sustainability” – depends on ones’ perspective : jury still out ones’ perspective : jury still out


AcknowledgementsAcknowledgements

• Numerous state Mines’ departments, Numerous state Mines’ departments, libraries, mining companies, some libraries, mining companies, some consultants and several other people have consultants and several other people have helped with the research to datehelped with the research to date

• Mineral Policy Institute (Sydney, NSW)Mineral Policy Institute (Sydney, NSW)

Dr Gavin M Mudd Institute for Sustainable Water Resources (Civil Eng)

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