Activated carbon is a black powder, granular or pellet-shaped amorphous with porous carbon. The main component is carbon, and it also contains a small amount of oxygen, hydrogen, sulfur, nitrogen, and chlorine. It also has a fine structure like graphite, but the grains are small and the layers are irregularly stacked. Has a large surface area (500-1000 m2 / g), has strong adsorption performance, can adsorb gas, liquid or colloidal solids on its surface; for gas, liquid, the mass of the adsorbed substance can be close to activated carbon The quality itself. Its adsorption is selective, and non-polar substances are easier to adsorb than polar substances. In the same series of substances, the higher the boiling point, the easier it is to be adsorbed, the higher the pressure, the lower the temperature, the higher the concentration, and the greater the amount of adsorption. Conversely, decompression and temperature increase are conducive to gas desorption. Commonly used for gas adsorption, separation and purification, solvent recovery, decolorant for sugar liquid, grease, glycerin, medicine, deodorant for drinking water and refrigerator, poison filter in gas mask, can also be used as catalyst or metal salt Catalyst carrier. The raw materials for the production of activated carbon in the early days were wood, hard nut shells or animal bones. Later, coal was mainly used. After carbonization and activation treatment, the activated carbon production methods were: ① steam and gas activation method. Carbon is activated by water vapor or carbon dioxide at 850-900 ¡ã C. ② Chemical activation method. Activated carbon can be obtained by using the gas released by the activator or impregnating the raw materials with the activator after high temperature treatment.
Activated carbon has a microcrystalline structure, and the arrangement of microcrystals is completely irregular. There are micropores (radius less than 20 [Angles] = 10-10 meters), transition holes (radius 20 to 1000), and large holes (radius 1000 to 100,000) It has a large inner surface and a specific surface area of 500-1700 m 2 / g. This determines that activated carbon has good adsorption properties, and can adsorb metal ions, harmful gases, organic pollutants, pigments, etc. in wastewater and waste gas. Industrial application of activated carbon also requires high mechanical strength and good abrasion resistance, its structure strives to be stable, and the energy required for adsorption is small to facilitate regeneration. Activated carbon is used for decolorization and deodorization of oils, beverages, food and drinking water, gas separation, solvent recovery and air conditioning. It is used as a catalyst carrier and an adsorbent for gas masks.
Activated carbon is a kind of multi-pored carbide with extremely rich pore structure and good adsorption characteristics. Its adsorption is made by physical and chemical suction, and its appearance is black. In addition to the main carbon, its composition also contains a small amount of hydrogen, nitrogen, and oxygen, and its structure looks like a hexagon. Due to the irregular hexagonal structure, it is determined that it has a large volume and high surface area. Characteristics: Each gram of activated carbon has a specific surface equivalent to 1,000 square meters.