Every activated carbon quotation lives or dies by four or five numbers. Read them right and you buy exactly the porosity your process needs; read them wrong and you either overpay for gold-grade carbon in a drain-water duty or watch a cheap grade break through in weeks. Here is what each line on the spec sheet actually tells you.
Iodine Number (mg/g) — the Micropore Meter
Iodine number approximates the surface area held in micropores — the pores that do the heavy lifting on small molecules in water treatment. 800 is a workable municipal grade, 1000 is a strong all-rounder, 1100–1200 is premium coconut territory. Two cautions: iodine tracks small-molecule capacity only, and a “typical 1000” from a trader is not a titrated 1000 from the batch you receive.
CTC (%) — the Gas-Phase Benchmark
Carbon tetrachloride activity measures vapor adsorption capacity, which is why solvent-recovery and air-purification buyers specify CTC rather than iodine. 50% covers general odor duty, 60% is the standard for VOC beds and honeycomb, 70% is a high-end pellet for deep solvent recovery. Roughly, CTC ≈ 2.2–2.5× butane activity if your reference sheet uses BWC.
Methylene Blue (mg/g) — Decolorization Power
MB value tracks mesopores — the pores sized for big color molecules. Sugar, syrup and pharma decolorization live on this number (120–200 mg/g for wood-based powders), and it barely correlates with iodine: a high-iodine coconut carbon can be a mediocre decolorizer. Match the test to the duty.
Hardness (%) — Will It Survive Your Plant?
Ball-pan hardness predicts attrition in backwashed filters, stripping columns and pneumatic transfer. Coal granular runs ≥90%; coconut ≥97% is why gold plants pay for it — every percent of carbon that turns to fines in a CIL tank is gold-bearing carbon you screen out and lose.
Ash, Moisture, pH — the Housekeeping Trio
- Ash (≤12% standard, ≤5% acid-washed): matters for pharma, food and any duty where leachables are audited.
- Moisture (≤5% as packed): you are buying carbon, not water — check it on the COA, not the brochure.
- pH: fresh carbon can push alkaline; sensitive processes should specify a washed, pH-neutral grade.
The One Rule That Saves Money
Specify by duty, then demand the batch COA. Our lab titrates iodine, CTC, MB, hardness, ash and moisture on every kiln batch, and the certificate that travels with your container is that batch’s own data. Send your current spec sheet to jinhaofeng298@163.com and we will match it grade for grade — or tell you honestly where you are over-buying.