Mode of Occurences, Indian occurrences, Reserves etc

1. GRAPHITE:
 Graphite is a crystalline form of the element carbon. Historically, graphite was called black lead or plumbago. It
consists of stacked layers of graphene.
 Graphite occurs naturally and is the most stable form of carbon under standard conditions.
 Synthetic and natural graphite are consumed on large scale uses in pencils, lubricants, and electrodes. Under high
pressures and temperatures, it converts to diamond. It is a weak conductor of heat and electricity.
 Natural graphite is categorized into two commercial varieties (i) crystalline (flaky) graphite and (ii) amorphous
graphite. Both flaky and amorphous varieties of graphite are produced in India.
 Graphite occurrences are reported from various States but the deposits of economic importance are located in
Chhattisgarh, Jharkhand, Odisha and Tamil Nadu. (Source: IBM, Year Book 2019)
 As per NMI database, based on the UNFC system, the total reserves/resources of graphite about 194.89 million
tones, out of which 7.96 million tones are in the Reserves category and 186.92 million tones are placed under
Remaining Resources category. (Source: IBM, Year Book 2019)
 Arunachal Pradesh accounts for 37% of the total resources which is followed by Jammu & Kashmir (32%), Odisha
(9.7%), Jharkhand (9%) and Tamil Nadu (4%). (Source: IBM, Year Book 2019)
 In terms of reserves, Jharkhand has the leading share of about 52% followed by Tamil Nadu (42%) and Odisha
(6%). (Source: IBM, Year Book 2019)
STRUCTURE AND PROPERTIES:
Graphite has a simple 2D layered or sheeted structure with strongly bonded carbon atoms in a hexagonal ring-structure,
resembling a honeycomb pattern. Each carbon atom is covalently bonded to just three others, leaving one electron spare.
This results in atoms arranged in flat layers of hexagons, between which is a bunch of free, delocalized electrons made up
from the spare electrons.
 It is very soft: Its hardness on Moho’ Scale is between 1.5 and 2.
 It has a very low specific gravity: - 2.09 - 2.23, Average = 2.16.
 It is nearly inert when it comes into contact with almost any other material; resistant to most chemicals.
Figure 1: Graphite Structure

2.  In spite of being a non-metal, it is exceptional conductor of electricity. Its conductivity is roughly one-third that of
copper, half that of aluminum and twice that of steel at room temperature.
TYPES AND MODE OF OCCURRENCE:
Graphite is a stable form of carbon, occurring in gneisses and meta-sediments. It is present, usually in the form of layers &
lamellae with grey-to-black metallic luster and have a greasy feel.
Natural graphite is categorized into three commercial varieties
a. Crystalline graphite
b. Flake graphite
c. Amorphous / Microcrystalline graphite
Crystalline graphite occurs in high grade metamorphic rocks like granulite’s, in the form of veins and large lumps. They
form by precipitation of C-O-H-bearing hydrothermal fluids.
Flake graphite and Amorphous or Micro-crystalline graphite occur as disseminations within meta-sediments that have
undergone high grade regional metamorphism or contact metamorphism. The carbonaceous matter within the argillites
(shales) converts to graphite under high temperature conditions which may prevail during syn-diagenetic or contact
metamorphism.
The quality of graphite depends upon its physical qualities and carbon content as indicated below.
a. Amorphous / Microcrystalline: 70 - 85% Carbon content
b. Crystalline Flake: 85 - 90% Carbon content
c. Vein-type (Lump or Chip): 90 - 95% Carbon content
List of Uses of Graphite
Graphite has been used since ancient times. It has a wide range of applications in the modern world too. Let’s look at some
common uses of graphite below.
Writing Materials
The common use of graphite is in making the lead in pencils. This lead is a mixture of clay and graphite which is in an
amorphous form.
Lubricants / Repellents
Graphite is one of the main ingredients in lubricants like grease, etc. This mineral reacts with atmospheric water vapor and
creates a thin film or layer over the surface applied and thus reduces friction. Graphite is also used in car brakes and clutches.
The powdered form of lump graphite is also used in paints. Graphite by nature is water-repellent. So it offers a protective
coating on wood and other surfaces.
Refractories
Due to its high tolerance to heat and un-changeability, Graphite is a widely used refractory material. It finds its use in the
manufacturing industry and it helps in the production of glass and steel as well as processing of iron.
Nuclear Reactors
Graphite can absorb fast-moving neutrons. As a result, it is used in reactors to stabilize nuclear reactions.
Electrical Industry
Crystalline flake graphite is used in the manufacturing of carbon electrodes, brushes, and plates needed in dry cell batteries
and the electrical industry. Interestingly, natural graphite is also processed into synthetic graphite. This type of graphite is
useful in lithium-ion batteries.

3. Graphene Sheets
Graphite can be used to make graphene sheets. These sheets are said to be 100 times stronger and 10 times lighter than steel.
This derivative of graphite is further used in making lightweight and strong sports equipment. Many are considering future
applications in the field of medical and aerospace industry.
WORLD REVIEW:
 The world resources of graphite are believed to exceed 800 million tons of recoverable reserves. However, world
reserves of graphite have been placed at 300 million tons of which Turkey accounts for 30% followed by China &
Brazil 24%, Mozambique 8%, Tanzania 6%, India & Vietnam (3% each) and Mexico, Dem. P. R. of Korea &
Madagascar (1% each).
 World production of graphite was 1.0 million tons in 2018 same as in the preceding year. China continued to be the
leading producer, with a share of about 63% which is followed by Mozambique (11%), Brazil (10%) and India &
Dem. P.R of Korea (4% each).
Figure 2: World Reserves of Graphite (Natural)
Figure 3: World Production of Graphite