The expandable graphite was first discovered by the German scientist Shafautl when he immersed the graphite into concentrated sulfuric acid and nitric acid in 1841. But until the year of 1963, The Union Carbide Company in the United States first applied the patent of preparation of sealing material by the expansion graphite, and it was real used in the industrial production in the beginning of 1968 . Later, Countries in the world have launched the expansion of graphite research and development, and get serious scientific research and results, so in the current , the expansion graphite has become a kind of very important function of graphite materials.
The expandable graphite can be rapid expansion, expansion ratio of up to several tens to hundreds of even thousands of times under high temperature heating , the apparent volume of expanded graphite was 250 ~ 300mL/g or more, the graphite after expansion is wormlike, its size between a few tenths of millimeters to a few millimeters, with a large number of unique network like porous structure in the interior, called expanded graphite or graphite worm, the expanded graphite has many special properties.
The expandable graphite can be used in iron and steel, metallurgy, petroleum, chemical engineering, aerospace, atomic energy and other industrial sectors, its application fields are very widely. For example, the expandable graphite can be used as a flame retardant, and is used for fireproof plastic products, fire retardant composite materials and products;
The expandable graphite can be used as a multi band stealth smoke agent and shielding materials, it’s widely used in the military field. The flexible graphite products which is made of expanded graphite was known as the "seal of the king." it plays an important role in the field of mechanical seal, fireproof material; the expanded graphite can be used as a sorbent material for recycling of waste and wastewater treatment as the microbial carrier in the field of environmental protection.
