5 core indicators
(Take water treatment/air purification as an example)
1. Lock in key performance parameters
Iodine adsorption value (Iodine Number)
Significance: Measures the adsorption capacity of micropores (<2nm) and determines the efficiency of removing small molecular organic matter (such as pigments, residual chlorine).
Selection criteria:
Drinking water grade: ≥1000 mg/g
Industrial wastewater: ≥800 mg/g
Testing tips: Ask the supplier for ASTM D4607 or GB/T 12496.8 test report, focusing on laboratory temperature and humidity conditions.
Carbon tetrachloride adsorption rate (CTC Adsorption)
Significance: Reflects the capacity of mesopores (2-50nm) and determines the interception capacity of macromolecules such as VOCs and oils.
Selection criteria:
Air purification: ≥60%
Gold purification: ≥75%
Pore Size Distribution
Ideal ratio (determined by BET method):
Micropores (<2nm): 40%-50%
Mesopores (2-50nm): 50%-60%
Macropores (>50nm): <5%
Application matching:
Gas adsorption: priority given to those with a high proportion of mesopores
Water treatment: balance of micropores and mesopores
Abrasion Resistance
Test method: RO-TAP vibrating screen simulates transportation loss (ASTM D3802)
Qualified line: ≥95% (to prevent powdering and clogging of filter element during use)
Ash content and pH value
Food grade: ash content ≤3%, pH 6-8
Industrial grade: ash content ≤8%, pH can be relaxed to 5-9
II. Scenario-based selection decision tree 🌳
Step 1: Clarify the application scenario
Water purification → Focus on iodine value + pore size uniformity
Air filtration → Focus on CTC value + bulk density (recommended ≥480kg/m³)
Precious metal recovery → ultra-high CTC value + pickling pretreatment
Step 2: Calculate the cost-effectiveness formula
Cost-effectiveness per ton = (adsorption capacity × number of regenerations) / (unit price + regeneration cost)
Example: The unit price of a coconut shell charcoal is $1200/ton, which can be regenerated 3 times. The adsorption capacity is 1.7 times that of coal-based charcoal, and the long-term cost is reduced by 52%
Step 3: Sample measurement verification
Simple detection method:
Take 1g of activated carbon and soak it in 10ml of methylene blue solution (0.1%)
High-quality products should be completely decolorized within 5 minutes
Stand for 24 hours to observe whether the color returns (the color return indicates that the recycled material is doped)
III. Traceability of supplier product raw materials
Steam activation: The temperature must reach 900-1100℃, and the activation time must be ≥45 minutes
Reject chemical activation: Residues from the phosphoric acid method may cause secondary pollution
Packaging and shelf life
Double-layer moisture-proof packaging (inner PE film + outer woven bag)
Unopened shelf life must be ≥18 months
IV. Avoidance guide ⚠️
Identification of low-price traps
Prices are 15% lower than the market price → Bamboo charcoal/fruit shell charcoal may be added
When the iodine value drops to 70% of the initial value, it needs to be replaced or regenerated
It is recommended to install a pressure difference monitoring device (alarm when the pressure difference increases by 15%)
