Graphite

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Graphite (Carbon) is commonly used for black lead also a component of a pencil. Graphite is a mineral. It maybe considered the highest grade of coal. Graphite is special because it can be conducted by electricity. It can be recycled and used for tools such as fishing rods and bicycle frames. Graphite is associated with other minerals like: quartz, calcite, mica, and tourmaline. G raphite has also been called blacklead and plumbago. Natural graphite is mostly used for refractories, batteries, steel making, expanded graphite, brake linings, foundry facings and lubricants. =====

Color: Iron Black to Steel grey. Lust-re: Sub-Metallic. Name: From Greek " graphein," to write; name given by German Chemist and mineralogist A.G. Werner in 1789 Formula: "C" Carbon.

History:

The mineral graphite is an allotrope of carbon. It was named by Abraham Gottlob Werner in 1789 from the Ancient Greek word "to draw/write", for its use in pencils, where it is commonly called lead (not to be confused with the metallic element lead). Unlike diamond (another carbon allotrope), graphite is an electrical conductor, a semi-metal. It is, consequently, useful in such applications as arc lamp electrodes. Graphite is the most stable form of carbon under standard conditions. Therefore, it is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds. Graphite may be considered the highest grade of coal, just above anthracite and alternatively called meta-anthracite, although it is not normally used as fuel because it is difficult to ignite. There are three principal types of natural graphite, each occurring in different types of ore deposit:

1.Crystalline flake graphite (or flake graphite for short) occurs as isolated, flat, plate-like particles with hexagonal edges if unbroken and when broken the edges can be irregular or angular; 2.Amorphous graphite occurs as fine particles and is the result of thermal metamorphism of coal, the last stage of coalification, and is sometimes called meta-anthracite. Very fine flake graphite is sometimes called amorphous in the trade; Lump graphite (also called vein graphite) occurs in fissure veins or fractures and appears as massive platy intergrowths of fibrous or acicular crystalline aggregates, and is probably hydrothermal in origin.







Graphite

Graphite uses depend mainly upon its type - amorphous, lumpy or flake. The flake graphite is known to show very low resistance to electrical conductivity. More the flaky particles, lesser the resistance and bulk density. This particular characteristic of flake graphite makes it useful in manufacturing of carbon electrodes, brushes and plates needed in dry cell batteries and the electrical industry. These days, amorphous or crystalline graphite has replaced flaky graphite in the production of brushes and plates. Graphite crucibles are used for melting aluminum, brass and other non-ferrous metals. These crucibles are produced by mixing graphite, sand and clay together and pressing it on the article at a high temperature. Flake and crystalline forms of graphite are the most used in manufacturing of crucibles. High grade graphite in amorphous and crystalline form, having the ability to remain suspended in oil, is used in the manufacturing of lubricants. Irrespective of the working condition, graphite shows very low friction which is why it is used in lubricants. It keeps the moving surface cool and minimizes the friction. Another flake graphite use is that it is used in foundry-facing to disallow molding sands from sticking to cast articles. In an atomic reactor, bricks of graphite are used as moderators. The graphite used in the nuclear field has to be low in the ability to absorb neutron and also needs to be of standard density and orientation. Of late, graphite uses in this field have expanded as it has started being used in blast furnace operations as well. One of the common uses of graphite is in manufacturing of pencils and paints. In production of paints, powdered form of lump graphite is used and since graphite is a natural water repellent, it is the best choice for giving a protective coating on wood. Graphite in amorphous form is used in the manufacturing of lead used in pencils. Amorphous graphite is preferred as it leaves a dark streak on paper. More fine the powder, darker the smear. In case the graphite is highly flaky, the smear loses its darkness. In China, graphite is used in the manufacturing of brake linings. Since car production is China is forever on the rise, so is the demand for graphite. Graphite is also used for making printing electrotypes. A thin layer of powdered graphite is applied on the wax impressions made, on which copper is deposited. The role of the thin layer of graphite is to provide negative electrical connection so that the process of electrolysis goes on smoothly, depositing copper on it. Source:[]
 * __Additional Uses for Graphite__**