The formation of activated carbon has three crucial stages.
Firstly, the raw materials for activated carbon originated from rich carbon containing substances, including coal, wood, coconut shells and so on. These raw materials need to undergo pretreatment to meet the conditions, for example cleaning, crushing, and screening, to remove impurities and control size. Such as, wood is usually chopped into blocks, while coal is crushed into particles of similar size. The selection of appropriate raw materials is crucial for activated carbon because different materials profoundly affect the pore distribution of activated carbon. Activated coconut carbon not only has uniform particles, but also has good adsorption performance.
The second stage is the carbonization process, which is the initial formation stage of activated carbon. The raw materials are heated in an oxygen-deficient environment to a temperature range of 400°C to 1000°C, to remove moisture and others. This step causes the organic matter to decompose and gradually transform into carbonized substances mainly composed of carbon. 
By controlling the heating rate and holding time, operators can prevent structural collapse to a certain extent and ensure the stability of the carbonized substances. After carbonization, the raw materials lose most of their organic tissues and gradually form a preliminary carbon skeleton. Take activated coconut carbon as an example.The carbon framework of the coconut shell carbon has removed impurities and moisture. Since activated carbon has not yet been fully formed, the specific surface area at this stage is relatively low, and the adsorption capacity is limited. Further activation is required to activate its structural performance.
The third stage, activation is a key process in the formation of activated carbon and is mainly divided into physical activation and chemical activation. The Two methods has different features in the process. Physical activation uses high-temperature gases such as steam as the activating agent and reacts to expand the pore structure. So this method can used in mainly factory. In contrast, chemical activation is more efficient, commonly using reagents such as potassium hydroxide to treat the raw materials at Chemical activation can generate more micropores at lower temperatures, significantly improving electrical conductivity and adsorption performance. So the method is usually used in Laboratory.Both methods have their advantages: physical activation is more environmentally friendly but takes longer; chemical activation is faster and more efficient but requires careful handling of chemical residues.
Finally, after the activation of activated carbon is completed, post-treatment is also necessary. This includes water washing to remove residual activating agents, followed by treatment in a high-temperature oven at over 800°C to enhance hardness. Subsequently, the activated carbon is dried and classified by sieving according to particle size to ensure consistency of the finished product. Strict post-treatment can prevent contamination and optimize the stability of activated carbon.
In conclusion, the formation of activated carbon is a complex process. Through meticulous control of the carbonization, activation, and post-treatment stages, ordinary carbon-containing organic materials can be transformed into highly efficient adsorbent activated carbon. This technology not only promotes the development of the environmental protection field but also provides new possibilities for energy storage and industrial catalysis. With technological progress, the production of activated carbon is evolving towards a more sustainable direction.