Acetylene Black

Acetylene carbon black is a high-purity acetylene obtained through the decomposition of by-products from calcium carbide or naphtha (crude gasoline) pyrolysis, followed by purification. It is produced as a byproduct of continuous pyrolysis. After the reactor is heated to above 800°C, the starting temperature for acetylene decomposition, acetylene is introduced to begin the thermal decomposition process. As it is an exothermic reaction, it proceeds automatically. To maintain consistent quality, the reaction temperature should be kept around 1800°C, which can be controlled via the external water-cooled jacket of the reactor. Acetylene carbon black is used as an anode material in manganese dry batteries, along with manganese dioxide and electrolyte. Compared to furnace black, it has a more developed crystalline and secondary structure, resulting in better electrical conductivity and liquid absorption properties. Due to the low content of heavy metals and other impurities, it has minimal self-discharge loss and excellent storage performance. Acetylene black has almost dominated the market and is expected to continue with the demand for dry batteries in the future.

Acetylene black is a fine black powder, with a relative density of 1.95 (by nitrogen displacement method). The apparent density is 0.2 to 0.3 g/cm3. Average particle size is 30 to 45 nm. Specific surface area is 55 to 70 m2/g. Iodine adsorption value is 60 to 80 gI2/kg. The purity of acetylene black is very high, with carbon content exceeding 99.5%, hydrogen content less than 0.1%, and oxygen content ranging from 0.07% to 0.26%. The pH value is between 5 and 7. It has a low resistivity, exhibiting excellent electrical and thermal conductivity, and is resistant to static effects.