Regarding the production of hard carbon

To produce hard carbon from heavy oil or asphalt, the pyrolysis process is typically used; this involves cracking the heavy oil or asphalt at high temperatures in an oxygen-free environment to thereby form hard carbon. The following are the detailed process steps: 1. Pretreatment: First, dehydrate and remove impurities from the heavy oil or asphalt to ensure the purity of the raw material, which helps improve the quality of the hard carbon. 2. Pyrolysis: The purified raw material is heated to high temperatures ranging from 500–1500°C in the absence of oxygen; the specific temperature depends on the properties of the hard carbon desired and the type of raw material used. In this process, the long-chain hydrocarbons in heavy oil or asphalt are broken down into small-molecule gases, liquids, and solid carbon (hard carbon). 3. Carbonization: The solid material obtained through pyrolysis can be heated to even higher temperatures to promote a tighter arrangement of carbon atoms, resulting in a structure of hard carbon. 4. Cooling and cleaning: After the carbonization reaction is complete, the hard carbon product needs to be cooled gradually, and cleaned to remove residual non-carbon substances and pyrolysis oil. 5. Post-treatment: If necessary, hard carbon can undergo processes such as shaping and surface treatment to meet specific application requirements. 6. Grading and packaging: Finally, the hard carbon is graded based on parameters such as particle size and purity, and then packaged for sale or further use. The entire production process of hard carbon requires precise temperature control and an oxygen-free environment to prevent the raw materials from burning or being converted incompletely into hard carbon. In addition, degassing and other control measures are also required to manage the gases and by-products generated during the process. .