The iodine value is a measure of the equilibrium mass of excess iodine adsorbed on the surface of activated carbon. This is a standard testing method. In adsorption theory, molecules of different sizes/functionalities will correspondingly physically adsorb at surface sites of different energies. Chemists measure and model adsorption in similar ways using different molecules. Since iodine is very small, it is a good indicator of the availability of activated carbon in very small/high density pores. The iodine number corresponds to the iodine balancing capacity of the activated carbon, and the amount of adsorbed iodine is related to the increased porosity of the activated carbon and is used as a general performance indicator. What is iodine value? Iodine value is a widely used parameter for activated carbon testing due to its simplicity and rapid test of adsorbent quality. It gives an estimate of its surface area and porosity. According to the ASTM D4607 standard, when the residual concentration of iodine is 0.02N (0.01 mol L-1), the iodine value is defined as the number of milligrams of iodine adsorbed by 1 gram of material, which is based on the three-point isotherm. How to measure? v Treat the sample with 10 mL of 5% (V/V) HCl. Boil the mixture for 30 seconds and then let cool to room temperature. Immediately add 100 mL of 0.1 N iodine solution to the mixture and stir for 30 seconds. Then filter the solution, and titrate 50 mL of the filtrate with 0.1N (0.05 mol L-1) sodium thiosulfate solution, using methanium (or starch) as an indicator. The amount of iodine adsorbed per gram of adsorbent was plotted against the residual iodine concentration using a logarithmic axis. If the residual iodine concentration is not within the range (0.008-0.04N), repeat the process using different carbon masses for each isotherm point. Regression analysis was performed on three points, and the iodine value was calculated as the adsorption amount when the residual iodine concentration was 0.02N.

Activated carbon uses 1. New home: used to absorb toxic and harmful gases such as formaldehyde, benzene series, ammonia and radon in the indoor air of new homes and continuously released into the air, and quickly eliminate decoration odors. 2. New furniture: used to absorb formaldehyde, benzene series, and various odors that are continuously released by new furniture. 3. Wardrobe, bookcase, shoe cabinet: deodorize, detoxify, dehumidify, prevent insects, deodorize, sterilize, preserve calligraphy and paintings, etc. 4. Bathroom: deodorization, sterilization, fresh air. 5. Floor: Deodorizes, moisture-proof, mildew-proof, insect-proof, and protects the floor from deformation. 6. Cars: Absorb various harmful gases in new cars and various odors in old cars. 7. Computers, household appliances, etc.: adsorb and reduce the damage of radiation gas to people. 8. Offices, hotels and other public places: purify the air and eliminate odors.

Speaking of activated carbon, the first thing everyone thinks of is to remove formaldehyde and absorb odors, but many people don’t know what activated carbon is. Today I will briefly explain to you “what activated carbon is”! Whether in our lives or in industry, the scope of use of activated carbon is very wide. It is made from coal, wood, fruit shells and other raw materials through carbonization, activation and post-processing. Currently, there are four common shapes: shaped activated carbon, powdered activated carbon, activated carbon fiber and granular activated carbon. What is activated carbon Activated carbon is also called activated carbon black. It is black powdery or granular amorphous carbon. In addition to carbon, the main components of activated carbon also include oxygen, hydrogen and other elements. The structure of activated carbon is due to the irregular arrangement of microcrystalline carbon and pores between cross-connections. Carbon organization defects will occur during activation. Therefore, it is a porous carbon with low packing density and large specific surface area. Activated carbon is odorless, tasteless, sandless, insoluble in any solvent, has selective adsorption capacity for various gases, and has high-capacity adsorption capacity for organic pigments and nitrogen-containing alkali. The total surface area per g can reach 500~1000m2. Relative density is about 1.9~2.1, apparent relative density is about 0.08~0.45

Recently, a customer inquired about activated carbon treatment of pharmaceutical wastewater. During the call, he asked, "With the same iodine adsorption value, which one is better, coal-based granular activated carbon or coal-based briquette activated carbon? The "briquetting forming process" of activated carbon is commonly known as "Agglomeration process" refers to the particle size expansion technology that uses methods such as pressure, stirring, and heating to aggregate and condense fine particulate materials such as dust or powder into larger blocks. The agglomeration process of activated carbon briquettes Purpose: to form fine powder materials into neat particles; to process the fine powder materials collected by the dust collector into a dense, chemically inert final product; to make several components into a uniform mixture; to improve the appearance of consumer goods and highlight their product features; Improve the fluidity of products in silos, feeding devices and other equipment; increase the bulk density of materials by 2 to 10 times; regulate the solubility of products; improve the chemical, energy and metallurgical performance of raw materials; improve the performance of raw materials in Ease of operation in transportation, storage or collection.