The difference between high purity carbon black, channel carbon black and pyrolysis carbon black
1. The significant difference between high purity carbon black and channel black and thermal black is that the degree of fusion or coalescence of its particles can be adjusted according to different uses. Therefore, furnace blacks in the same particle size range are divided into several derivative varieties with different structures. In addition, the oxygen content of furnace black is usually lower than that of channel black (less than 1%), and the surface is neutral or weakly alkaline.
2. According to the different forms of raw materials used, furnace black production can be divided into two types: gas furnace method and oil furnace method. The raw material and fuel used in the gas furnace method are natural gas. The fuel of the oil furnace method can be natural gas, coke oven gas, or liquid hydrocarbon, and the raw material is high aromatic oil, such as ethylene tar and anthracene oil. In the furnace black production process, the reactor is the core equipment. To produce different types of furnace black, reactors with different structural sizes are required. Air and fuel are burned in the reaction furnace, and the raw materials are atomized and sprayed into the burning flame, where they are pyrolyzed at high temperature to generate carbon black. The carbon black is suspended in the exhaust gas to form flue gas. After being quenched, the flue gas is sent to the air preheater and oil preheater for further cooling, and finally sent to the bag filter.
3. Carbon black is produced using natural gas as the main raw material and channel steel as the flame contact surface. This type of carbon black is called channel black. Compared with furnace black and thermal black, its particles are finer and the specific surface area is larger. At the same time, due to the specific production method, the surface is oxidized and contains more oxygen-containing functional groups and is acidic. The degree of coalescence of such carbon black particles is low. Because it contains more oxygen-containing functional groups, it can delay the vulcanization speed of rubber, improve the weather resistance of polyolefins and give the ink good fluidity and printing performance.
4. Using natural gas, coke oven gas or heavy liquid hydrocarbons as raw materials, in the absence of oxygen and flames, carbon black is generated by high-temperature pyrolysis, which is called thermal black. It is the lowest type of carbon black with the lowest specific surface area. It basically exists as a single spherical particle, does not fuse or coalesce into aggregates, and its surface oxygen content is very small (0.1% to 0.3%). There are three main varieties of thermal cracking black: medium thermal cracking black, non-polluting medium thermal cracking black and fine thermal cracking black. The nitrogen adsorption specific surface area of the medium thermal black is 6~10m2 /g, and the fine thermal black is 10~15m2 g.