Carbon black, also known as soot, is a pure black powder obtained by burning hydrocarbons in the absence of air to obtain extremely fine carbon black powder, and then separated from the exhaust gas. The raw materials of carbon black are tower bottom oil and creosote. Generally speaking, 2.2 metric tons of raw materials can produce one metric ton of carbon black. At present, besides China, carbon black factories in India and other countries still use tower bottom oil as raw material source, so the price of carbon black is closely related to
crude oil.

Carbon black is formed by the accumulation of spherical or chain particles with an average diameter of 5-30nm, and contains a microcrystalline structure with a diameter of 3-500nm inside, which can react with various free radicals. The specific gravity of carbon black is 1.8~1.9, the bulk specific gravity of granular carbon black is 0.35~0.4, and the bulk specific gravity of powdered carbon black is 0.04~0.08.