The physical properties of graphite can be varied through a range of manufacturing processes. This makes it suitable for a diverse range of applications requiring superior graphite properties to those of natural graphite.
The most common and versatile way to manufacture graphite is through a process known as Hot Isostatic Pressing (HIP). This combines heat, pressure and gas to convert powder in the solid state to fully dense components. This results in much better physical properties than is possible with melting or press and sinter technologies. HIP produces high purity, highly electrically conductive, low porosity materials ideally suited for batteries, semiconductors and glass industries.
Other industrial graphite production methods include pyrolysis and carbonisation, which produce coal-like products suitable for direct use as a fuel or for further processing. Graphite produced from these techniques can be used in the steel industry to raise the carbon content of molten iron, as well as in pencil leads and lubricants.
Natural graphite is produced from a mixture of coal and coke, which is heated to about 2400degC to form the graphitic material. This is then impregnated with a liquid phenolic resin under pressure, and then baked at about 3000degC until an adequate degree of graphitisation has been achieved.
Imerys offers a range of high purity, insulating synthetic graphite products with particle sizes from 2-micrometer powders up to blocks of