Coal pitch is one of the main products of coal tar deep processing.
It is a mixture of various hydrocarbons. It is a black high-viscosity semi-solid or solid at room temperature. It has no fixed melting point. It softens after heating and then melts. The density is 1.25-1.35g/cm3.
According to its softening point, it can be divided into low temperature, medium temperature and high temperature asphalt.
The yield of medium temperature pitch is 54-56% of coal tar. The composition of coal tar pitch is extremely complex, which is related to the properties of coal tar and the content of heteroatoms, and is also affected by the coking process system and coal tar processing conditions. There are many indicators that characterize the characteristics of coal tar pitch, such as pitch softening point, toluene insoluble matter (TI), quinoline insoluble matter (QI), coking value, and coal tar pitch rheology.
Coal pitch is used as a binder and impregnant in the carbon industry, and its performance has a great impact on the production process and product quality of carbon products. Binder asphalt generally uses medium temperature or medium temperature modified asphalt with moderate softening point, high coking value, and high β resin. As impregnant, use medium temperature asphalt with low softening point, low QI, and good rheological properties.