Graphite is natural form of carbon
Graphite is natural form of carbon. It is known for its excellent electrical conductivity, lubrication and resistant to heat. The material’s combination of high thermal stability, along with is conductive properties, allows graphite to be used in many heat intensive applications. Graphite preserves its strength in temperatures exceeding 3,600 degree Celsius and has the highest natural strength of any known material.
“Sri Lanka is the only nation in the world to produce a commercially viable export of vein graphite.”
Vein graphite is the rarest and most valuable form of graphite due to its high level of purity and accounts for less than 1% of world’s output. Sri Lanka is the only nation in the world to produce commercially viable export of vein graphite.
Vein graphite has the highest “degree of crystalline” perfection of all conventional graphite materials. In many applications vein graphite may offer superior performance since it has slightly higher thermal and electrical conductivity, which result from its high degree of crystalline perfection. Vein graphite also has the highest degree of cohesive integrity of all natural graphite materials. High cohesive “energy” means that vein graphite is easy to mould and can be formed into solid shapes without the aid of a binder addition. For producers, the higher the grade of graphite, the lower the milling and refining cost.
The graphite occurrences are in the form of veins ranging in thickness from veinlets less than 1mm thick to massive veins over 1m thick. The veins are usually located in the hinge zones of antiforms within granulite facies zones of the Precambrian Basement terrain that underlies much of Sri Lanka.
Common Graphite Uses
Graphite is used for its properties of high refractoriness, high electrical and thermal conductivity, chemical inertness and stability. Graphite has the highest thermal and electrical conductivity of all non-metals. The principal uses of natural graphite are in foundry facings, steelmaking, refractories, crucibles, pencils and lubricants. The global demand for graphite, based on market usage, in 2011 was 33% electrodes, 20% refractories, 6% lubricants, 5% foundries, 5% graphite shapes, 4% batteries, 2% friction products, 1% re-carburising, and 24% others (Roskills Natural and Synthetic Graphite: Global Industry Markets and Outlook, 8th Edition 2012). Industrial demand for graphite markets is forecast to continue to grow at its long term growth rate of 5% p.a. However, the growth potential for the graphite industry is forecast to expand due to emerging applications and green initiatives in nuclear energy, fuel cells, semi-conductors and Li-ion battery technologies.
- Amorphous and flake graphite are used for brake pads
- Graphite crucible used to hold molten metal
- Primarily used in recycling steel
- High purity and fine graphite used in lubricants to withstand extreme pressures and high temperatures. (used in high temperature gearing machinery)
- Lithium-ion batteries require graphite electrodes that are natural flake graphite and vein graphite.
- Batteries require 10 to 30x more graphite than lithium.
- Estimated demand will increase by 30-40% annually (Hybrid and electric cars, electronics, etc)
China accounts for about 70–80% of the world graphite supply (flake and amorphous) with Canada, North Korea, Mexico (amorphous), India and Brazil being the other major suppliers.
There has been speculation that China, in line with other industrial minerals such as magnesite and rare earths, will begin to restrict supply of graphite, particularly if (or rather when) technological advances bring in significant new markets. It is also speculated that the graphite mines in China are ageing and that some may be closed down thereby reducing supply. The country has also closed mines recently for environmental reasons.