Transcript Nickel Deposits Sulfide

Nickel Deposits
(The Sulfide Deposit Variety)
©2009 Dr. B. C. Paul
Acknowledgement is given to Natural Resources Canada, CSIRO,
webmineral.com, natires.com
Most form from Ultra-Mafic
Intrusions of Mantle Melt
Three Types of Magmatic Nickel
Sulfides
• Sudberry appears to be unique
– About 1.8 billion years a major meteor impact
– Melted down a crater about 200 km across
• Trigger mechanism is about the same
– Iron and nickel rich melts react with sulfur in
more crustal material
– The iron and nickel sulfides are in
disequilibrium and settle and concentrate in
the bottom of the melt.
The Subvolcanic Variety
Iron and nickel rich mantleLike melts work up into
Crustal material
Reactions with sulfur cause
Iron and nickel sulfides to
settle
The Surface Lava Flow Variety
The Komatite Lava Flow Variety
The iron and nickel sulfides
Settle out of deep ultra-mafic
Basalt lava flows.
The variety is smaller in size but
Has been quite numerous in
Australia
There are some indications that
The iron-nickel deposits were
More commonly formed in the
Past when the earth’s crust
Was less well formed and
Differentiated.
Grade Tonnage Relationships
Typical Log Distribution
With smaller deposits much more common than
large
Most are under 50,000,000 metric tonnes but a lot up to 100,000,000
Grade Tonnage Relations
Most Ore Mineralization is in the 0.7-3% Nickel Range
With Copper as a Major Coproduct
Cu grades are typically 0.2 to 2%
Pentlandite
Nickel can also
Substitute for iron
In Pyrrhotite
Fe2+4.5Ni4.5S8 34% Nickel
S.G. 4.8
Hardness 3.5-4
Color Bronze, Brown
Non Fluorescent Non Magnetic
Streak greenish black
Millerite
NiS
65% Nickel
S.G. 5.5
Hardness 3-3.5
Often looks rather fibrous – sometimes
Nicknamed pyrite hairs
(Almost never the main mineral but an
Important grade sweetener)
Non Fluorescent, Magnetic after heating
Streak greenish black
Pyrrhotite
Non Fluorescent
Magnetic
Streak
gray black
FeS
S.G. 4.6
Hardness 4
(its magnetic)
Where’s the Nickel? – Can substitute
Some of the iron with Nickel
Time Frame for Nickel Deposits
Processing of Nickel Sulfides
• Ore is ground to
liberate minerals
– Pyrrhotite may be
pulled out by magnetic
separation
Flotation and Pyrometallurgy
– Flotation is used to collect nickel and copper
minerals
– Multi-Step Pyrometallurgy is used
• May roast off part of the sulfur
• Then smelter concentrates
• Often regrind the slag and have another flotation or
separation stage
– When get about 90% nickel
• Dissolve the nickel with acid
• Electroplate out pure metals
Uses of Nickel
Uses of Nickel
4%
10%
Stainless Steel
Non-Iron Alloys
52%
34%
Electroplate
Other
Metric Tonnes of Nickel Produced
and In Reserve
Other
Zimbabwe
70000000
Venezuela
60000000
South Africa
Russia
50000000
Phillipines
New Caledonia
40000000
Indonesia
Greece
30000000
Dominican Republic
Cuba
20000000
Columbia
China
10000000
Canada
Brazil
0
MinedX20
Reserves
Botswana
Australia
Nickel Price
Sustained prices around $3 - $4 /lb
With spikes going up to $7 or even $25 when there was a belief
That supply would not keep up with demand