1. Introduction: Carbon black (also known as carbon black) is a kind of black powdery amorphous carbon. Carbon black is composed of spherical or chain-shaped particles with an average diameter of 2~3nm, and contains microcrystalline structure with a diameter of 3~500nm, which can react with various free radicals. Carbon black is mainly used as rubber reinforcing agent, used in automobile tire manufacturing, plastic additives, dyes, ink and other industries. 2. Production: Production of carbon black pigment Carbon black is petroleum products and asphalt coal tar products. It cannot be produced under negative pressure and insufficient air, but is formed by incomplete combustion or pyrolysis of hydrocarbons at high temperature. 1) production technology of lamp black: the earliest production method of carbon black in history is the production technology of lamp black. In this process, raw materials are burned on the flat-fired iron plate with a diameter as high as 1.5m, and the combustion gas containing carbon black is collected by the exhaust hood lined with bricks, and then reaches the deposition device through the elbow (bend 1/4) and the fire tube. In order to control the characteristics of carbon black produced, it should be ensured that the raw materials are not completely burned mainly near the gap between the combustion disk and the exhaust hood. However, in the slightly entering pipeline, the combustion is heated in the absence of oxygen, thus forming larger carbon black particles. For these reasons, the particle size distribution is wide, and the main feature is that the particles are coarse. Because only a small part of the particles formed between the combustion disk and the exhaust hood can contact with oxygen in the air, these carbon blacks have only a small amount of surface oxides, the corresponding PH value is neutral, and there are few volatiles. 2) Production process of gas black: the name gas black comes from its production process: when heated, the raw hydrocarbon is first gasified, and then brought into the burner by spontaneous combustion gas (energy supply), and carbon black is generated in a large number of fan-shaped flames sprayed by these bat-shaped burners. Because each flame is small and burns in the air, the formation of carbon black is very different from the production process of lamp black (incomplete combustion). Here, the carbon black particles are very fine. According to different species, the average particle size is between 10~30nm, and the average particle size of gas black is 13nm. On the burning flame, there is a slowly rotating water-filled drum. Carbon black is deposited on the drum and scraped off after scraping. When the temperature is still high, the newly generated carbon black is in contact with oxygen in the air, so it is partially oxidized to form a large number of acidic groups, and the corresponding gas black PH value is in the acidic range. And about 6% of volatiles can be obtained, which represents the surface oxide content. 3) Production process of tank black: This production process takes natural gas as raw material, and the process of tank black is similar to the gas combustion process of gas black production process. When natural gas burns, many fan-shaped flames will be emitted, and the products obtained are similar to gas black, but the difference is that the carbon black precipitation tank here adopts a flat water-cooled U-shaped tank. For ecological and economic reasons, this method was stopped many years ago. The production of gas black will not affect the ecological environment, and this gas black process is still in use. 4) Furnace black production process: gas black is produced in an open atmosphere, but the furnace black production process is carried out in a closed furnace under oxygen-deficient conditions. Instead of many small fires, use big flames. Oil is used as raw material and combustible gas is added to make it reach the required temperature in the furnace. The required pigment black can be obtained by changing the production process conditions of furnace black. For example, under different conditions, the average particle size of carbon black can reach a wide range, from 80nm to as small as 15nmj, and even as small as gas black. But for the same particle size, gas black and furnace black are still different, mainly because of the different surface chemistry. The furnace black product is coarse, with an average particle size of 40nm. In addition, when the furnace black production process is adopted, a small amount of alkaline compounds or other additives can be added to change the aggregation degree and type of aggregates, thus obtaining carbon black with high structure or low structure.