Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Chromite 101


Published on - In this presentation by Spider Resources Board of Directors member Dr. James Franklin, P.Geo. explains the importance of Chromite in today's world

Published in: Education, Business, Technology
  • Be the first to comment

Chromite 101

  1. 1. <ul><li>Chrome </li></ul><ul><li>Where does it come from? </li></ul><ul><li>Why are the new discoveries in the “Ring of Fire” so significant? </li></ul><ul><li>What does this discovery mean for North American steel-making? </li></ul>
  2. 2. Chrome: Essential in the Green Economy! <ul><li>harden steel, to manufacture stainless steel, and to form alloys </li></ul><ul><li>plating to produce a hard, beautiful surface; prevents corrosion. </li></ul><ul><li>gives glass an emerald green colour; responsible for the green colour of emeralds and the red colour of rubies </li></ul><ul><li>a catalyst </li></ul><ul><li>dichromates such as K 2 Cr 2 O 7 are oxidizing agents and are used in quantitative analysis and also in tanning leather </li></ul><ul><li>lead chromate as chrome yellow pigment </li></ul><ul><li>compounds are used in the textile industry and for tanning leather </li></ul><ul><li>used by the aircraft and other industries for anodizing aluminum </li></ul><ul><li>forming refractory bricks and shapes - high melting point, moderate thermal expansion, and stable crystalline structure </li></ul>
  3. 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. 4. Chromite Use in the United States
  5. 5. Where does chrome come from? <ul><li>Occurs in the mineral chromite (FeCr 2 O 4 ) </li></ul><ul><li>Mostly obtained from “hard-rock” mines </li></ul><ul><li>Some from beach sands containing chromite </li></ul><ul><li>Almost all deposits occur in a relatively rare rock type – “ultramafic” rocks </li></ul><ul><ul><li>These formed beneath ancient oceans or in rifts connected to oceans </li></ul></ul><ul><ul><li>Rocks hosting these deposits have unique compositions (very rich in magnesium) and formed at very high temperatures (~1400 o C) </li></ul></ul><ul><ul><li>Chromite occurs in layers or pods in the ultramafic intrusion </li></ul></ul><ul><li>A few deposits are in beach sands that formed from the weathering of ultramafic rocks </li></ul>
  6. 7. Why are Ultramafic Rocks So Important? <ul><li>These form from high-temperature melting of the mantle </li></ul><ul><li>The melts contains >1000 parts per million (ppm) chrome, along with similar amounts of nickel, copper, cobalt, and other valuable elements </li></ul><ul><li>Melts that form related mafic rocks, such as ocean-floor basalt contain only about 100ppm of these elements. </li></ul><ul><li>All other rocks contain much less of these elements – typically only 1 to 10ppm </li></ul><ul><li>However, to make an economic deposit, some specific things must affect the melt: </li></ul><ul><ul><li>It must rise rapidly from the place in the mantle where melting occurred, ideally without the crystallization of any minerals </li></ul></ul><ul><ul><li>It must become contaminated </li></ul></ul><ul><li>Let’s look at the way in which these deposits form </li></ul>
  7. 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
  8. 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?
  9. 10. How Does Chromite Form <ul><li>These diagrams are the result of experiments that duplicate the natural process </li></ul><ul><li>This shows how the main silicate minerals, olivine and pyroxene , along with chromite , crystallize from a high temperature melt, as follows: </li></ul><ul><li>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 </li></ul><ul><li>As it cooled, it reached Point B , the boundary where both olivine and chromite crystallize </li></ul><ul><li>If the melt is not changed in composition, it continues to cool, precipitating olivine and chromite along the line until it reaches point C . </li></ul><ul><li>At C , it begins to precipitate pyroxene, and much less chromite. </li></ul><ul><li>No massive chromite layers formed!! </li></ul>
  10. 11. How Are the Massive Chromite Layers Formed <ul><li>As olivine and chromite precipitate together, from B to E, chromite only forms about 1% of the rock, and isn’t recoverable </li></ul><ul><li>At point E, the melt becomes contaminated, because some of the roof to the magma chamber drops into it </li></ul><ul><li>This contaminant should be silica (quartz) – rich, with a low melting temperature </li></ul><ul><li>Contamination causes the melt to shift composition to point H in the “chromite-only” precipitation zone </li></ul><ul><li>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 </li></ul><ul><li>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. </li></ul>
  11. 12. Summarizing: Contamination Causes Chromite Layers
  12. 13. The Chrome:Iron Ratio in Chromite is Critical <ul><li>Only Cr:Fe ratios close to or above 2 are considered economically important </li></ul><ul><li>Most Canadian occurrences have Cr:Fe ratios of less than 1.4. </li></ul><ul><ul><li>Bird River, Manitoba: 37% Cr 2 O 3 , Cr:Fe 0.84 </li></ul></ul><ul><ul><li>Big Trout Lake, Ontario: 13.2% Cr 2 O 3 </li></ul></ul><ul><ul><li>Muskox, NWT: </li></ul></ul><ul><li>Chrome from South Africa contains about 40% Cr 2 O 3 ; Cr:Fe ratio of 1.2-1.5 </li></ul><ul><li>McFaulds Lake: ~40% Cr 2 O 3 ; Cr:Fe of 1.9-2.0 </li></ul>
  13. 14. <ul><li>World chromite production </li></ul><ul><li>South Africa, India and Kazakhstan = 78% </li></ul><ul><li>Brazil, Finland, Russia, Zimbabwe and Turkey =12% </li></ul><ul><li>Canada poised to be the next major producer </li></ul>
  14. 15. World Resources <ul><li>Total (non 43-101 compliant) resource estimates (USGS) </li></ul><ul><li>South Africa: 2,910 mt </li></ul><ul><li>Kazakhstan: 1,110mt </li></ul><ul><li>India: 1,090 mt </li></ul><ul><li>Russia: 291mt </li></ul><ul><li>Zimbabwe: 215 mt </li></ul><ul><li>Turkey: 208 mt </li></ul><ul><li>Brazil: 190 mt </li></ul><ul><li>Finland; 174 mt </li></ul><ul><li>Oman: 102 mt </li></ul>These are the major suppliers of chrome ore today: where will Canada fit?
  15. 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
  16. 17. Where Does Canada Fit In? <ul><li>“ 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. </li></ul><ul><li>Big Daddy (Spider-KWG-Cliffs) and its relatives, Blackbird (Noront), Black Thor and Black Label (Cliffs) are not fully defined, and are semi-contiguous. </li></ul><ul><li>A total resource in excess of 200mt, although not yet proven, is probable </li></ul><ul><li>Canada will soon place between 4 th and 7 th in the world, and much more will be discovered </li></ul><ul><li>The McFaulds area will become the largest supplier of chrome in the Americas . </li></ul>
  17. 18. Spider’s Big Daddy Discovery in the Ring of Fire <ul><li>280km north of Nakina and the CNR Railroad </li></ul><ul><li>Chrome Canada planning railroad link </li></ul><ul><li>“ Ring” has best potential as North American supplier </li></ul>Ring of Fire JV Chromite
  18. 19. Gravity Map Outlines Potential Resource <ul><li>Because of its high specific gravity, chromite zones are accurately outlined by gravity surveys </li></ul><ul><li>These provide the resource boundaries; about nine km of total strike length </li></ul><ul><li>Note the distinct, elongate strong anomalies (purple)’ these are near-massive chromite </li></ul>
  19. 20. Magnetics Help Define Geology Ultramafic rocks have high magnetic susceptibility pattern (dark red)
  20. 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
  21. 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
  22. 23. The Future: Ring of Fire- The World’s Next Major Chrome Producer <ul><li>Initial metallurgical work shows that a good quality product can be produced from the massive chromite zone </li></ul><ul><li>This chromite is amenable to upgrading to ferrochrome, the desired product for the steel industry </li></ul><ul><li>Initial drilling indicates that the deposits extend deeper, and further along strike, than already determined </li></ul><ul><li>Nearby Ni-Cu-PGE, Cu-Zn and Au discoveries all contribute to the economic potential of this region </li></ul>
  23. 24. Acknowledgements <ul><li>Rick Kruse and Don Hoy of Freewest Resources provided the slide of the gravity surveys, and the Freewest reports provided information on resource contents. </li></ul><ul><li>Prof. James Scoates (UBC) provided the phase diagram and chromite model slides and some of the pictures from his lecture material. </li></ul><ul><li>Prof. Jim Mungall (U of Toronto) helped to develop the geological map </li></ul><ul><li>Much of the economic data were obtained form various USGS files and reports. </li></ul><ul><li>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. </li></ul>