Every week we receive inquiries that read simply: "Please quote activated carbon." Unfortunately, activated carbon is not one product — it is a family of materials whose performance differs by 3–4x depending on specification. Buying the wrong grade means either paying for capacity you don't need, or worse, a system that fails its discharge targets. This guide explains the four numbers that matter.
Iodine number (mg/g) measures the amount of iodine adsorbed by one gram of carbon, and roughly indicates the volume of micropores — the pores that capture small molecules. For coal-based carbon, typical industrial grades range from 700 to 1100 mg/g:
Rule of thumb: each +100 mg/g of iodine number adds roughly 5–8% to price. Choose the lowest grade that still meets your treatment target with a safety margin — not the highest number on the page.
Carbon tetrachloride (CTC) activity (%) measures adsorption of larger organic molecules and is the key indicator for gas-phase work: air purification, solvent recovery, VOC removal. Our GS-30 columnar series spans 25% to 80% CTC. If your supplier quotes only iodine number for an air application, ask for CTC — two carbons with identical iodine values can differ by 20%+ in CTC performance.
Methylene blue adsorption (mg/g) indicates mesopore volume — the pores that handle larger, color-body molecules. It matters most for decolorization: sugar refining, pharmaceutical intermediates, food and beverage. For drinking water grades, iodine number is more relevant; for decolorization jobs, compare methylene blue first.
Two "coal-based" carbons with identical paper specs can behave very differently in service, because performance depends on the raw coal and activation process. Ningxia Taixi anthracite is globally recognized for low ash and exceptional mechanical strength — carbons made from it hold their integrity through loading, backwashing and regeneration cycles.
| Application | Type | Iodine Number | Other Key Specs |
|---|---|---|---|
| Drinking water | Granular Ø1.5 mm | 800–1000 mg/g | Hardness ≥95%, ash <12% |
| Wastewater polishing | Granular / crushed | 700–900 mg/g | pH 7–10 |
| Gold CIL/CIP | Crushed 6×12 mesh | ≥950 mg/g | Hardness ≥97%, low platelets |
| Air purification / VOC | Columnar Ø3.0 mm | 850–1070 mg/g | CTC 50–80% |
| Desulfurization | Activated coke | ≥350 mg/g | Sulfur capacity ≥20 mg/g |
| Sugar / pharma decolorization | Powdered | Per application | Methylene blue prioritized |
Send us your application and target parameters — our engineers will recommend the most cost-effective grade from our GS series, arrange free samples, and support you through pilot testing. Contact Guangsheng Activated Carbon →