First of all, we must ask what graphite is. Graphite is simply the dark solid that we thought of as “lead” in pencil, although there is no lead in it. From that, you all know now graphite is black and is very, very soft. So you ask your self: How can that conduct electricity? It’s not metal!
Well, the reason for graphite’s ability to conduct electricity lies in its atomic structure. It’s not metal, but a mineral. As a mineral, it is mostly composed of carbon atoms just like diamonds. Unlike diamonds though, graphite has a different atomic structure. Diamonds use up all 4 carbon atoms that bond together. Graphite, on the other hand, uses only 3 carbon atoms, which leaves one atom free to move around and pass on the electrical charges.
Graphite and Copper
In a way, graphite is a bit similar to copper. They are both soft and malleable, and can conduct electricity. Like copper, graphite is also used in polishes and paints. Graphite can withstand the heat generated by electricity running through its atoms. It will also not burn out when you place a light bulb between the graphite and the source of electricity.
Uses of Graphite
Because of its ability to conduct electricity and withstand heat, graphite is used in making electrodes, as lubricant for machines, and in nuclear reactors to absorb neutrons. Graphite is used as lubricant in machines, which have to be operated at high temperatures, because oil or grease vaporizes immediately at high temperatures. Unlike oil or grease, graphite is stable and can withstand heat. It is used in the form of dry powder or mixed with water or oil. When mixed with water, the graphite mixture is called “aqua-dag,” and when mixed with oil, the mixture is called “oil dag.”
Graphite is also used for making electrotypes for printing, in the following manner. Wax impressions are made, and then a thin layer of graphite powder is applied. Copper is deposited on this thin layer. The layer of graphite is used to give the negative electrical connection for carrying out electrolysis to deposit copper on it . After coating the required thickness, the wax can be melted out by dipping it in hot water.
How Safe Is Graphite?
Graphite is generally safe, unlike lead, which can poison us. It is inactive and inert to almost all chemicals. It does not burn in air, even when heated to high temperature, but if heated in oxygen, it burns completely to form only carbon dioxide. Graphite oxidizes to carbon dioxide when heated with concentrated sulphuric acid and potassium dichromate.
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