Calcined carbon black is a high-purity acetylene obtained through the decomposition of by-products from calcium carbide or naphtha (crude gasoline) pyrolysis, followed by continuous pyrolysis to produce carbon black. 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. The internal temperature of the reactor can be controlled through the water-cooled jacket on the outer cylinder. Acetylene black is used as an anode material in manganese dry batteries, alongside manganese dioxide and electrolyte. Compared to furnace black, it has a more developed crystalline and secondary structure, resulting in better conductivity and wettability. Due to the low presence of heavy metals and other impurities, the loss caused by self-discharge is minimal, and its storage performance is excellent. Acetylene black almost dominates the market and is expected to continue alongside the demand for dry batteries in the future.

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