The Acheson process is used to produce synthetic graphite, typically by heating carbon-containing materials at high temperatures.
Raw Material Preparation:
Petroleum coke or other carbon-rich materials are mixed with a binder like coal tar pitch. The mixture is shaped into desired forms, such as blocks or rods.
Placement in Furnace:
The shaped carbon material is packed with a sand-like material (silicon carbide) in an electric furnace to help control the temperature during heating.
Heating (Graphitization):
An electric current is passed through the furnace, heating the material to temperatures around 2500–3000°C. At these temperatures, carbon atoms rearrange into graphite’s crystalline structure.
Cooling:
The material is slowly cooled down over a period to ensure proper crystallization. Rapid cooling can cause cracking or defects in the graphite structure.
Graphite Extraction:
Once cooled, the synthetic graphite is removed from the furnace, with impurities being brushed or blasted off.
Final Processing:
The synthetic graphite may undergo further shaping, cutting, or purification, depending on its intended application, such as electrodes or battery-grade graphite.
Synthetic Graphite Production is ecologically more damaging. The Energy intensive Acheson process produces notable amount of NOx, SOx and particulate matter pollutants.