Chromite 101

http://www.spiderresources.com - In this presentation by Spider Resources Board of Directors member Dr. James Franklin, P.Geo. explains the importance of Chromite in today's world

1. Chrome
Where does it come from?
Why are the new discoveries in the
“Ring of Fire” so significant?
What does this discovery mean for
North American steel-making?

2. Chrome: Essential in the Green Economy!
•harden steel, to manufacture stainless steel, and to form alloys
•plating to produce a hard, beautiful surface; prevents corrosion.
•gives glass an emerald green colour; responsible for the green colour of
emeralds and the red colour of rubies
•a catalyst
•dichromates such as K
2Cr
2O
7 are oxidizing agents and are used in
quantitative analysis and also in tanning leather
•lead chromate as chrome yellow pigment
•compounds are used in the textile industry and for tanning leather
•used by the aircraft and other industries for anodizing aluminum
•forming refractory bricks and shapes - high melting point, moderate
thermal expansion, and stable crystalline structure

3. Some Uses
Ball bearings: Almost everything
“runs” on them!
Wheels for
your
wheels!
Something to
“dye” for!!
For really
strong
pipes…and
much more!

4. Chromite Use in the United States
End Uses of Chromium
0
100,000
200,000
300,000
400,000
500,000
600,000
700,000
1975 1980 1985 1990 1995 2000
Metric tons
MetallurgicalOther

5. Where does chrome come from?
•Occurs in the mineral chromite (FeCr
2
O
4
)
•Mostly obtained from “hard-rock” mines
•Some from beach sands containing chromite
•Almost all deposits occur in a relatively rare rock
type – “ultramafic” rocks
–These formed beneath ancient oceans or in rifts
connected to oceans
–Rocks hosting these deposits have unique compositions
(very rich in magnesium) and formed at very high
temperatures (~1400
o
C)
–Chromite occurs in layers or pods in the ultramafic
intrusion
•A few deposits are in beach sands that formed from
the weathering of ultramafic rocks

7. Why are Ultramafic Rocks So Important?
•These form from high-temperature melting of the mantle
•The melts contains >1000 parts per million (ppm) chrome,
along with similar amounts of nickel, copper, cobalt, and other
valuable elements
•Melts that form related mafic rocks, such as ocean-floor basalt
contain only about 100ppm of these elements.
•All other rocks contain much less of these elements – typically
only 1 to 10ppm
•However, to make an economic deposit, some specific things
must affect the melt:
–It must rise rapidly from the place in the mantle where
melting occurred, ideally without the crystallization of any
minerals
–It must become contaminated
•Let’s look at the way in which these deposits form

8. Step 1: Melting in the upper mantle,
melt rises to form a magma pool , 5 -10
km below the earths surface
Step 2: Melt begins to cool,
precipitating mg-rich minerals
(olivine, pyroxene) and chromite
Step 3: Crystals settle to the bottom of
melt chamber, forming layers
Step 4; magma is recharged
many times, forming multiple
layers

9. Chromite forms distinct layers, but how does it accumulate without olivine or
pyroxene? Need to stop silicate precipitation but continue chromite accumulation.
How does this happen?

10. How Does Chromite Form
These diagrams are the result of
experiments that duplicate the
natural process
This shows how the main
silicate minerals, olivine and
pyroxene, along with chromite,
crystallize from a high
temperature melt, as follows:
•The melt was introduced into a
magma chamber as a liquid,
4-6km below the earth's surface
Minerals began to crystallize at
Point A
•As it cooled, it reached Point B,
the boundary where both olivine
and chromite crystallize
•If the melt is not changed in
composition, it continues to cool,
precipitating olivine and
chromite along the line until it
reaches point C.
•At C, it begins to precipitate
pyroxene, and much less
chromite.
No massive chromite
layers formed!!

11. How Are the Massive Chromite Layers Formed
•As olivine and chromite precipitate
together, from B to E, chromite only
forms about 1% of the rock, and
isn’t recoverable
•At point E, the melt becomes
contaminated, because some of the
roof to the magma chamber drops
into it
•This contaminant should be silica
(quartz) – rich, with a low melting
temperature
•Contamination causes the melt to
shift composition to point H in the
“chromite-only” precipitation zone
•Until all of this contaminate is used
up (from points H to G), only
chromite precipitates, and settle to
the bottom of the partially-filled
magma chamber, forming a massive
chromite layer
•Once the melt cools and reaches
the co-precipitation line, chromite is
then ‘diluted’ by olivine, and
eventually (points C and D)
pyroxene, to make dunite and
peridotite.

12. Summarizing: Contamination Causes Chromite Layers

13. The Chrome:Iron Ratio in Chromite
is Critical
•Only Cr:Fe ratios close to or above 2 are considered
economically important
•Most Canadian occurrences have Cr:Fe ratios of
less than 1.4.
–Bird River, Manitoba: 37% Cr
2
O
3
, Cr:Fe 0.84
–Big Trout Lake, Ontario: 13.2% Cr
2
O
3
–Muskox, NWT:
•Chrome from South Africa contains about 40%
Cr
2
O
3
; Cr:Fe ratio of 1.2-1.5
•McFaulds Lake: ~40% Cr
2
O
3
; Cr:Fe of 1.9-2.0

14. World chromite production
•South Africa, India and Kazakhstan = 78%
•Brazil, Finland, Russia, Zimbabwe and Turkey =12%
•Canada poised to be the next major producer

15. World Resources
Total (non 43-101
compliant) resource
estimates (USGS)
•South Africa: 2,910 mt
•Kazakhstan: 1,110mt
•India: 1,090 mt
•Russia: 291mt
•Zimbabwe: 215 mt
•Turkey: 208 mt
•Brazil: 190 mt
•Finland; 174 mt
•Oman: 102 mt
These are the major suppliers of chrome ore today: where will
Canada fit?

16. Some Important Statistics
Price began to vary in the 1980’s, in response to economic conditions
In the past 10 years, rapid price increases caused by demand in China and India
Production has increased dramatically; large reserves in South Africa, Kazakhstan
and India sufficient to meet demand BUT….
Abilities of major suppliers to produce more are largely dependant on power
availability; already limited in all three large producers
Consumption per person has doubled in 50 years; industrialization of large nations
drives this

17. Where Does Canada Fit In?
•“Ring of Fire” already has measured, indicated (total
36.2 mt) and inferred (total 148 mt) resources, and many
of the zones are still open to depth and along strike.
•Big Daddy (Spider-KWG-Cliffs) and its relatives,
Blackbird (Noront), Black Thor and Black Label (Cliffs)
are not fully defined, and are semi-contiguous.
•A total resource in excess of 200mt, although not yet
proven, is probable
•Canada will soon place between 4
th
and 7
th
in the world,
and much more will be discovered
•The McFaulds area will become the largest
supplier of chrome in the Americas.

18. Spider’s Big Daddy Discovery in the Ring of Fire
•280km north of Nakina and the CNR Railroad
•Chrome Canada planning railroad link
•“Ring” has best potential as North American supplier
Ring of Fire
JV Chromite

19. Gravity Map
Outlines Potential
Resource
oBecause of its high
specific gravity,
chromite zones are
accurately outlined by
gravity surveys
oThese provide the
resource boundaries;
about nine km of total
strike length
oNote the distinct,
elongate strong
anomalies (purple)’
these are near-massive
chromite

20. Magnetics Help Define Geology
Ultramafic rocks have high magnetic susceptibility pattern (dark red)

21. Geological Interpretation
From geophysical and drill data, a preliminary geological map outlines the
distribution of key target rocks- the ultramafics- that host Cr and Ni occurrences

22. Cross-section: Big Daddy Deposit
Note the
exceptional
continuity of the
chromite zone to
depth
It occurs at a very
distinct change in
rock type
(peridotite and
pyroxenite)
This came abut
because during
cooling, the
precipitation of
silicate minerals
was interrupted by
melt contamination
This contamination
enabled chromite
to accumulate
without dilution

23. The Future: Ring of Fire- The World’s Next
Major Chrome Producer
•Initial metallurgical work shows that a good
quality product can be produced from the
massive chromite zone
•This chromite is amenable to upgrading to
ferrochrome, the desired product for the steel
industry
•Initial drilling indicates that the deposits extend
deeper, and further along strike, than already
determined
•Nearby Ni-Cu-PGE, Cu-Zn and Au discoveries
all contribute to the economic potential of this
region

24. Acknowledgements
•Rick Kruse and Don Hoy of Freewest Resources provided
the slide of the gravity surveys, and the Freewest reports
provided information on resource contents.
•Prof. James Scoates (UBC) provided the phase diagram
and chromite model slides and some of the pictures from
his lecture material.
•Prof. Jim Mungall (U of Toronto) helped to develop the
geological map
•Much of the economic data were obtained form various
USGS files and reports.
•Various 43 - 101 reports from Noront Resources and the
Spider - KWG - Freewest joint venture are the source of
additional data on resource contents. The author of this
presentation cannot verify the accuracy of these resource
estimations, but these are done to standards accepted by
the relevant regulatory agencies.