An Overview of Cu-Ni Deposits in Minnesota: A Geological Perspective Jim Miller Department of...
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Transcript of An Overview of Cu-Ni Deposits in Minnesota: A Geological Perspective Jim Miller Department of...
An Overview of Cu-Ni Deposits in An Overview of Cu-Ni Deposits in Minnesota: A Geological PerspectiveMinnesota: A Geological Perspective
Jim MillerDepartment of Geological Sciences
Precambrian Research CenterUniversity of Minnesota Duluth
LAKE SUPERIOR BINATIONAL FORUMMarch 25, 2013
Virginia, MN
Outline•Why are these deposits here?•History of exploration•Why “sulfide” mining?•What are the uses of Cu, Ni, and Pd and where else can they be found•Why these ores will be mined, someday
A Looming A Looming Stewardship Stewardship Question for Question for
Minnesotans:Minnesotans:
When should we develop
this immense copper-nickel-precious metal
mineral resource?
_______________
THE THE MIDCONTINENMIDCONTINENT RIFTT RIFT_______________An attempt at continental rifting 1.1 billion years ago
A. Rift Magmatism
Gabbro
MantlePlume
BasaltFlows
CrustMantle
B. Sediment Infilling Sandstone
C. Compression
1,109-1,086 Ma
1,090-900 Ma
1,000-900 Ma
Tectonic and Magmatic Tectonic and Magmatic Evolution of the Evolution of the
Midcontinent RiftMidcontinent Rift
Midcontinent Rift Midcontinent Rift Exposure in the Exposure in the
Lake Superior Lake Superior RegionRegion
Duluth Complex
Partridge River Intrusion
South Kawishiwi Intrusion
Sequential Sequential Emplacement Emplacement of Duluth of Duluth Complex Complex IntrusionsIntrusions
Sulfur Contamination creating the Cu-Ni-PGE Sulfur Contamination creating the Cu-Ni-PGE Sulfide Deposits of the Duluth ComplexSulfide Deposits of the Duluth Complex
SSCu Ni Co Pd + Pt + Au
SS
$/t
on
Cu Prices 1948-2006
Cu-Ni Regional Study
PGE discovered
LTV shuts down
Cu-Ni sulfide discovered at Spruce Rd
INCO drills Maturi
Bear Creek drills Babbitt
State land opens for mineral leasing Active exploration drilling
Polymet, Teck, Franconia, Wallbridge (Duluth Metals)
State land closed to new mineral leasing
Current $ - 7,060
Current Exploration ActivityPolymet – NorthmetTeck American – MesabaTwin Metals MN – Nokomis, Maturi, Dunka Pit, Birch Lake, Spruce Rd Encampment– South Filson Cr.
The Current SituationThe Current Situation
Mineralogy of Magmatic Mineralogy of Magmatic Cu-Ni Sulfide DepositsCu-Ni Sulfide Deposits
Sulfide MineralsPyrrohotite – FeS1-x
Chalcopyrite - CuFeS2
Pentlandite - (Fe,Ni)9S8
Bornite - Cu5FeS4
Chalcocite - Cu2SCobaltite – CoAsSPt Group Minerals – Pt, Pd, Au, Bi, Te, As, ...
Silicate/Oxide MineralsOlivine - (Mg,Fe)2SiO4
Plagioclase – (Ca,Na)(Al,Si)4O8
Augite – Ca(Mg,Fe)Si2O6
Titano-magnetite – (Fe,Ti)3O4
The Environmental ChallengePreventing Acid Rock Drainage (ARD)
2FeS2(s) + 7O2(g) + 2H2O(l) →
2Fe2+(aq) + 4SO42-(aq) + 4H+(aq)
Why Sulfide Mining?Most of the world’s metals comes from sulfide minerals
ChalcopyriteCuFeS2 Bornite
Cu5FeS4
CobaltiteCoAsS
SphaleriteZnS
GalenaPbS
ChalcociteCu2S
MolybdeniteMoS2
Pentlandite(Fe,Ni)9S8
CinnabarHgS
THEN
NOW
Sudbury, Ont.
Hydrometallurgy
Roasting/Smelting Monchegorsk, Russia
Separating Metal Separating Metal from Sulfurfrom 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 6.9% 30% (Chile (41%), Canada (33%))
Nickel 0% 43% (Canada (44%), Russia, Australia, Norway)
Cobalt 0% 81% (Norway, Russia, China, Canada)
Palladium 5.9% 58% (Russia (44%), South Africa (37%))
Data from USGS Mineral Commodity Summaries35% from Recycled Cu
Cu in a Standard Car with Combustion Engine
43-55 lbs
Cu in a Prius80 lbs
COPPERCOPPER An Important Metal in a Green Economy
NW Mining Association, 2009
PGE – Platinum Group ElementsPGE – Platinum Group ElementsPt – Platinum, Pd – Palladium, Os – Osmium, Ru – Ruthenium, Rh – Rhodium, Ir - Iridium
Bushveld ComplexBushveld ComplexSouth AfricaSouth Africa
Supplying the 70% of the World’s Platinum
Merensky Reef, Eastern Bushveld ComplexMerensky Reef, Amplats Mine, Rustenburg, SA
Palladium: Palladium: ““The Environmental Metal”The Environmental Metal”Pd
Uses
Stillwater Mine (Montana)Stillwater Mine (Montana)Only Precious Metals Mine in the U.S.
(owned by Noril’sk Nickel)
Sulfide Smelters in RussiaIn 1998, responsible for ~half of SO2
in the northern hemisphere
Noril’sk, RussiaCu-Ni-PGE Deposits
Supplies 45-60% of the World’s Palladium
World Class Ores of the Duluth ComplexWorld Class Ores of the Duluth Complex
#1 or 2 in contained Copper#4 in contained PGE#3 in contained Nickel
Compared to other Magmatic Sulfide Deposits, the Duluth Complex is:
Only the Bushveld, Great Dyke, and Noril’sk contain
more PGE
From Peterson, 2010
World Scale of the Maturi World Scale of the Maturi DepositDeposit
Nokomis
From Peterson, 2010 and DM press release 12/2012
Maturi
Maturi
Maturi
The Largest UNDEVELOPED Cu-Ni Deposit on The Largest UNDEVELOPED Cu-Ni Deposit on EarthEarth
From Peterson, 2010
Duluth deposits are perceived as low grade. But compared to the source of most of the world’s copper - Porphyry Copper Deposits...
…the Duluth Complex ores are HIGHER GRADE with MORE CONTAINED METAL than nearly all porphyry systems.
The largest copper ore deposits in the USA are on this diagram, and the Duluth Complex ores are much larger then all of them.
Stewardship question - If not now, when?Stewardship question - If not now, when?
CONCLUSION: CONCLUSION: The base and precious metal deposits of the Duluth Complex are a World Class Resource that will be mined …. SOMEDAY