Less than 1% of the world's production of graphite, only being produced out of Sri Lanka.
Vein graphite also known as "Sri Lankan" graphite is the rarest and most valuable form of graphite. Purity of the graphite ranges from 80-99% carbon. Sri Lanka is the only country to date to commercially produce vein graphite.
Only about 1% of the world's graphite is vein graphite. This type of graphite is formed from the direct deposit of graphitic carbon from subterranean, high temperature fluids. When these fluids travel through flake graphite and conditions are right, solid graphitic carbon “precipitates” directly from the fluid phase resulting in fillings known as vein graphite.
Typical veins of graphite can run from centimeters to meters wide with the purest graphite in the middle of the vein furthest from the hard rock wherein it resides.
Typical veins are shaft mined where the mining process must follow, or chase, the vein along the same flow route as the original fluids travelled in and out of cracks in the hard rock. This type of mining is both time consuming and expensive and can result in a meter of graphite find turning into a centimetre of graphite mine. It is an expensive gamble.
About half of world output. Low purity, low quality, low value.
When coal meets graphite. Amorphous graphite is almost negate of crystalline structure, it is almost always granular except in very fine grinds where you might find some minute flake structure. Amorphous graphite is the least graphitic of the natural graphite types with a purity rate of only 20-40 percent carbon, at best.
The original organic carbon of coal is deposited and converted with heat, time and pressure into anthracite coal through metamorphosis which can produce microcrystalline graphite.
Typically the graphite deposit runs adjacent to the coal and becomes part of the metamorphosis process. This is often why armorphous graphite has an ash content much like coal does. This is the lowest quality graphite with the lowest price. This type of graphite will never have a future in the green energy revolution or in the development of graphene.
About half of world output. Larger flakes are more valuable.
About 53% or half of the graphite found in the world is flake graphite. Flake graphite varies in both the size of the flake and the purity (the pure graphitic carbon content). Large flake with high purity is not common.
The average purity rate for flake graphite is anywhere between 80-99.9% typically occurring in medium to smaller flake size. The smaller the flake the less carbon purity in the end product because more binder is needed to adhere the small flakes together.
The larger the flake and the purer the graphite carbon content the higher the resale value. Flake graphite is found throughout the world with the top five producers being China, Brazil, India, North Korea and Canada.
The flake size does vary around the world but in hard rock mining found in China, North Korea and Canada, often the flake size is decimated in the mining process.
In saprolitic rock, such as in the DNI Madagascar properties, the flake size is not damaged and the purity is high. The DNI Vohitsara property has found some of the largest flakes of graphite in the world with a tested purity rate of up to 97.9%.
Size and purity = value.
Physical Properties and Applications of Graphite
- Atomic Structure: Graphite is composed of a stack of carbon atom layers, each arranged in hexagonal groups that form one atom thick sheets called graphene.
- Properties: Strong, Flexible, Heat resistant, Highly conductive both Thermally and Electrically, Chemically inert, Highly refractory.
- Applications: Li-Ion batteries, Fuel cells, Flame retardants, Crucibles, Brake pads, Ceramics, Lubricants, Heat sinks.
- Systematic price increases for large flake.
- New product development, particularly in high purity applications such as lithium-ion batteries, solar panels, and semiconductors.
- Constrained supply from major producers; only one current North American supplier.