The production methods of activated charcoal mainly include the following:
1. Physical method: This method mainly prepares activated carbon through high-temperature pyrolysis and activation processes. Firstly, remove impurities from raw materials such as sawdust and grind them, then carbonize them at high temperatures, and then activate them to form a developed pore structure. Finally, after rinsing, screening, and testing, the finished product is obtained.
2. Chemical method: refers to the use of chemical activators to treat raw materials, and then prepare activated carbon through carbonization and activation processes. The main production methods for activated charcoal are chemical methods, including zinc chloride activation, phosphoric acid activation, potassium hydroxide activation, and other chemical activation methods. This method can produce activated carbon with developed pore structure and huge activated carbon surface area, which is suitable for purification, separation, purification and carrier, recovery, precious metal extraction and other fields.
3. Phosphoric acid method: The production method of phosphoric acid from activated charcoal involves mixing raw material powder with phosphoric acid solution, followed by carbonization and activation. This is a special chemical method that uses phosphoric acid as an activator. The preparation process of the phosphoric acid method mainly includes three stages: phosphorylation, carbonization, and activation. After phosphorylation, phosphorus element is introduced to a certain extent, which promotes the subsequent carbonization reaction and thus prepares high activated carbon surface area. This can generate developed mesoporous structure and activated carbon surface area in activated carbon, thereby improving adsorption capacity and filtration rate. This method is suitable for decolorization, refining, and other processes in the food industry.
The above three methods each have their own characteristics and are suitable for different production conditions and product requirements. In actual production, various factors such as the type of raw materials, carbonization temperature, activation temperature, and activation atmosphere need to be considered to optimize the production process and improve product quality.