Introduction and product classification of coal tar pitch

Coal pitch, is short for coal tar pitch, coal tar distillation processing after the removal of liquid distillate residue, belongs to a kind of artificial asphalt, generally for the viscous liquid, semi-solid or solid, black and shiny, generally containing carbon 92~94%, hydrogen about 4~5%. Coal tar pitch is a major product in the process of coal tar processing and is an irreplaceable raw material for carbon production.

The purpose of tar distillation is to concentrate compounds with similar boiling points in tar into corresponding fractions for further processing and separation of monomer products. The residue of distillate extraction is coal tar pitch, accounting for 50% ~ 60% of coal tar.

According to the different softening points, coal asphalt is divided into low temperature asphalt (soft asphalt), medium temperature asphalt (ordinary asphalt), high temperature asphalt (hard asphalt) three categories, each category has No. 1 and No. 2 two grades.

Coal bitumen is mainly used in the following fields:

* Fuel: Solid components can be mixed with heavy oil or made into slurry used, can play the role of replacing heavy oil.

Paint: Paint that adds rosin or turpentine and fillers when cooking oil for waterproof buildings or pipes. It is suitable for outdoor steel structure, concrete and masonry waterproof layer and protective layer, and can be painted and painted at room temperature.

* Road construction, building materials: generally mixed with petroleum asphalt, coal asphalt and petroleum asphalt compared, there is an obvious quality gap and durability gap. The coal asphalt is poor in plasticity, poor in temperature stability, brittle in winter, softening in summer, and aging fast.

* Binder: Do electrode, anode paste and other carbon products binder, generally modified asphalt. Generally, the modified asphalt is prepared from medium temperature asphalt. In China, kettle heating process is generally adopted, and gas is used as fuel to heat the asphalt in the reactor. Finally, solid modified asphalt is obtained through separation and granulation.

* Asphalt coke: solid residue of coal asphalt after high temperature retorting or delayed coking. Asphalt coke is often used as a raw material for special carbon materials, which is indispensable for manufacturing semiconductor and solar panel production equipment. It is widely used as electrode material for aluminum refining, carbonized material for electric furnace steelmaking and special carbon product raw material for semiconductor.

* Needle coke: refined soft asphalt by raw material pretreatment, delayed coking, high temperature calcination three processes, mainly used in electrode manufacturing and special carbon products. The products made from its raw materials are characterized by low resistivity, low thermal expansion coefficient, strong heat resistance, high mechanical strength and good oxidation resistance.

* Carbon fiber: special fiber with more than 92% carbon content obtained from asphalt by refining, spinning, pre-oxidation, carbonization or graphitization.

* Oil felt, activated carbon, carbon black and other uses.