Future of Base and Precious Metal Mining in Minnesota

Jim MillerDepartment of Geological Sciences

University of Minnesota Duluth

A Looming Stewardship Question for Minnesotans:

When should we develop

this immense copper-nickel-

precious metal mineral

resource?

_______________

THE MIDCONTINENT RIFT_______________An attempt at continental rifting 1.1 billion years ago

1,109-1,086 Ma

1,090-900 Ma

1,000-900 Ma

The Evolution of the Midcontinent

Rift

Creation of the Cu-Ni-PGE Sulfide Deposits of the Duluth Complex

SCu

NiCo

Pd + Pt + Au

S

History of Cu-Ni-PGE Exploration in the Duluth Complex1948 – Cu-sulfide mineralization discovered by F.W. Childers1951 – Childers and Whiteside drill first exploration drill hole at Spruce Road1954 – INCO begins drilling program at Maturi deposit1958 – Bear Creek (Kennecott) begins drilling program at Babbitt deposit1966 – Minnesota opens state lands for minerals lease sale1967 – INCO sinks shaft at Maturi deposit1969 – Total of 198,000’ of drill core acquired1974-78 –State conducts Cu-Ni Regional Study1974-82 – State suspends lease sale1976 – AMAX sinks shaft at Babbitt deposit1981 – AMAX abandons Babbitt deposit1985 – High PGE values discovered at Birch Lake deposit1988 – Lehmann and Assoc. begin drilling of the Birch Lake deposit1997-2000 – Polymet, Teck Cominco,

Franconia, Wallbridge (Duluth Metals) begin active exploration drilling

2007 – Total of 322,000’ of drill core acquired

0

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8,000

1948

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$/to

n

Cu Prices 1948-2006

Cu-Ni Regional Study

PGE discovered

LTV shuts down

Current Exploration ActivityPolymet – NorthmetTeck American – MesabaDuluth Metals – Nokomis, Maturi, Dunka Pit, Birch Lake, Spruce Rd

Encampment– South Filson Cr.

The Current Situation

Mineralogy of Magmatic Cu-Ni Sulfide DepositsSulfide MineralsPyrrohotite – FeS1-xChalcopyrite - CuFeS2Pentlandite - (Fe,Ni)9S8Bornite - Cu5FeS4Chalcocite - Cu2SCobaltite – CoAsSPt Group Minerals – Pt, Pd, Au, Bi, Te, As, ...

Silicate/Oxide MineralsOlivine - (Mg,Fe)2SiO4Plagioclase – (Ca,Na)(Al,Si)4O8Augite – Ca(Mg,Fe)Si2O6Titano-magnetite – (Fe,Ti)3O4

The ChallengePreventing Acid Mine Drainage

2FeS2(s) + 7O2(g) + 2H2O(l) → 2Fe2+(aq) + 4SO4

2-(aq) + 4H+(aq)

Another Inconvenient TruthMost of the world’s metals comes from sulfide minerals

ChalcopyriteCuFeS2 Bornite

Cu5FeS4

CobaltiteCoAsS

SphaleriteZnS

GalenaPbS

ChalcociteCu2S

MolybdeniteMoS2

Pentlandite(Fe,Ni)9S8

CinnabarHgS

Upper Michigan:America’s First Mineral Rush 1844-1972

of Native Cu

THEN

NOW

Sudbury, Ont.

Hydrometallurgy

Roasting/Smelting Monchegorsk, Russia

Separating Metal from Sulfur

United States –The #1 consumer of mineral resources, that produces little for itself

% Mined by US % Imported for Metal vs. Total Mining US consumption

Copper 7.7% 40%(Chile (30%), US, Indonesia, Peru)

Nickel 0% 54%(Russia, Australia, Canada, Indonesia)

Cobalt 0% 78%(Congo (30%), Zambia, Australia, Canada)

Palladium 6.6% 78%(Russia (44%), South Africa (38%))

Statistics from US Geological SurveyMineral Commodity Summaries, Jan. 2006

Data from 2006 USGS Mineral Commodity Summary

31%

Cu in a Standard Car with Combustion Engine

43-55 lbs

Cu in a Prius80 lbs

COPPERAn Important Metal in a Green Economy

NW Mining Association, 2009

PGE – Platinum Group ElementsPt – Platinum, Pd – Palladium, Os – Osmium, Ru – Ruthenium, Rh – Rhodium, Ir - Iridium

Bushveld ComplexSouth Africa

Supplying the 70% of the World’s Platinum

Merensky Reef, Eastern Bushveld ComplexMerensky Reef, Amplats Mine, Rustenburg, SA

Palladium: “The Environmental Metal”

PdUses

The Stillwater Mine (Montana)Only Precious Metals Mine in the U.S.

(owned by Noril’sk Nickel)

Sulfide Smelter in Monchegorsk, RussiaIn 1998, responsible for 50% of SO2

in the northern hemisphere

Noril’sk, RussiaCu-Ni-PGE Deposits

Supplies 60% of the World’s Palladium

Copper and Nickel Resources of the Duluth Complex

Hulbert & Ekstrand, 2008

WORLD CLASS!

That will be mined....

SOMEDAY !

STEWARDSHIP: the individual’s responsibility to manage his life and property with proper regard to the rights of others

Webster’s Ninth New Collegiate Dictionary (1987)

EDITORIAL:Responsible stewardship of mineral resources demands that we make sensible and fair choices of where, how, and when to acquire critical resources we need for today and for the future.

If not now, when?