Graphite Mine-To-Markets Overview

Mining

Crushing

Grinding

Floating

Drying

Jumbo

Micronization

Purification

Medium

Shaping & Coating

Fine

MARKETS

Flake Graphite

Micronized Flake

Graphite

High Purity Micronized

Flake Graphite

Large

Sorting

Spherical Graphite

Click on any object for more information.

MINE

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Graphite Mining Where China India Brazil Canada Sri Lanka

How Almost all graphite is mined from open pits. Graphite mines range in size from small, quarry-style operations to large open pit mines. Some underground vein mining is done in Sri Lanka on very high grade hydrothermal material.

Who Chinese companies Grafite Nacional Grafite do Brasil Stratmin Timcal Valence

Graphite mining in southern Quebec circa 1890.

Graphite is mostly mined from open pits.

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Crushing and Grinding

Crushing Crushing is the first stage of processing after extraction. Ore is fed through crushers to produce crushed rock.

Grinding Grinding is the second stage and reduces the crushed rock to a specified size. For graphite, the object is to grind enough to be able to liberate the graphite with as few impurities as possible while at the same time preserving flake integrity to the extent possible.

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Floating / Flotation

Floating or Flotation Graphite is naturally hydrophobic and is liberated from host material relatively easily. Crushed material and water create a slurry in a flotation cell (shown here on a bench scale). Graphite rides to the surface by attaching to bubbles that are created by agitation of the slurry. Often a reagent is used as a catalyst to accelerate the process. The graphitic froth is then skimmed off.

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Drying Drying The first stage of removing moisture content from the slurry is performed with a filter press, shown here at bench scale. The concentrate is then baked in an industrial furnace at high temperatures to complete the drying process.

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Sorting (Particle Size Distribution)

Particle Size Distribution Particle size, or flake size, refers to the size of a particular flake of graphite. Particle Size Distribution refers to the relative quantities of flake sizes within a sample.

Particle Size Distribution Analysis Distribution analysis is performed using a sieve shaker and a series of screens with progressively tighter screen spacing, or mesh. The sample is put in the top and then shaken until the sample has been sorted into the different size classes.

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Flake Graphite Products

About Flake Graphite Products Sold by flake size:

Jumbo Large -100 mesh

Packaging: From jar to 1 tonne Super Sack Target Markets Lubricants (drilling) Technology R&D

Jumbo flake or +48 resembles glitter.

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Micronization Fun Fact #1 Micronization is the process of grinding a material to extremely fine grades that are measured in microns, or millionths of a metre.

Fun Fact #2 Micronized Flake Graphite is typically produced in sizes between 45 and 10 microns.

Fun Fact #3 There is zero waste by-product generated by micronization. Material trapped in the dust collectors is the finest of all and actually has the highest market value of any of the micronized products.

Micronization is used for many food products.

A look inside a micronization unit.

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Micronized Flake Graphite

Target Markets Pencils Carbon Brushes Lubricants Powder Metallurgy

Products: MFG-45, MFG-25, MFG-15, MFG-10 Purity Range: 94%-97% Cg Size: 45-10 micron

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Purification

Purification Purifying graphite, or removing the impurities from graphite, typically involves heat and/or chemistry to increase the percentage of carbon and decrease the percentage of non-carbon elements present with the graphite. To purify a large quantity, a crucible is filled with micronized flake graphite and loaded into a specialized industrial furnace which is then heated to 2300 degrees Centigrade. It may be necessary to flow gas(es) through the furnace to achieve very high purity levels. The non-carbon elements bond to the gases and are pulled up and out of the furnace. After being maintained at temperature for several hours, the crucible requires up to 48 hours to cool before the material can be safely handled.

Tolling Providers Purifying graphite is a highly specialized process that requires a substantial investment in equipment and the appropriate operating environment. Purification is available on a tolling basis from equipment manufacturers and other service providers.

Furnaces at TevTech’s facility in Billerica, Mass.

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High Purity Micronized Graphite

High levels of purity are required for applications with more demanding requirements, such as energy storage. Alkaline batteries, which are still pervasively used, are an important target market. Target Markets Composites Lubricants Friction Dispersions Pencil Battery

Products: HMG-45, HMG-25, HMG-15, HMG-10 Purity Range: 99.5C to 97.9C Size: 45-10 micron

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Shaping & Coating Graphite

Shaping Shaping smooths all the rough edges off the graphite, resulting in well-rounded, potato-shaped particles.

Coating Smoothed particles are coated as the final step in the spheroidization process. Carbon is typically used.

After Micronized Flake Graphite has been purified, it is shaped and then coated to make Spherical Graphite.

Not actual carbon particles, for illustration purposes only. High purity and consistent particle shape are required to obtain the performance required by the applications.

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Spherical Graphite

Gigafactory coming online will impact graphite demand significantly.

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-  high purity graphite (99.9%+)

-  micronized to 5-15 microns.

China dominates nearly all production for uncoated spherical graphite, while Japan, South Korea and China hold the vast majority of the world’s spherical graphite coating capacity.

Appendices

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The Graphite Value Chain

Flake Graphite

Micronized Flake Graphite

High Purity Micronized Graphite

Spherical Graphite

Products

Mining

Micronizing

Purifying

Shaping, Coating

Processes Step Cost

Sell Price

$300 - 1200 $700 - 1800

$300 - 500 $2000 - 3000

$800 - 1000 $3500 - 4000

$1600 - 2000* $7000 - 10000

Approximate, in $USD per tonne

Value

* There is a yield factor unique to the Spherical Graphite stage due to loss in the manufacturing process, which can be significant..

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Graphite Processing Glossary

Assay Beneficiation Bulk sample Caustic Bake Cleaning Comminution Concentrate Crushing Drying Exfoliation Flake Flake Size

Micron MSDS Particle Size Purify Purity Reagent RO-TAP Roughing Sedimentary Silica Slurry

Froth Flotation Gangue Grinding Head grade Hydrothermal Intercalation Impurities Leaching Mesh

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