By the YELI Technical Team · Updated September 2026 · 7 min read
"How much activated carbon do I need?" is one of the first questions every gold plant asks — whether you are designing a new CIL circuit, expanding an existing one, or simply trying to budget next year’s consumables. There is no single number, but there is a reliable way to estimate it. Start with the quick table below, then work through the four numbers that decide it.
Quick Sizing Table: From Circuit Volume to Annual Tonnage
Estimates assume a working concentration of 15–20 g of carbon per litre of slurry and a monthly make-up of ≈7% of in-circuit inventory (see Section 3 for the working range). For context, a mid-size West African CIL plant of roughly 1,000–2,000 tpd typically holds 30–40 tonnes of gold recovery activated carbon in circuit.
| Circuit slurry volume | Initial charge (15 g/L → 20 g/L) | Monthly make-up (≈7%) | Annual make-up (≈7%) |
|---|---|---|---|
| 1,600 m³ (≈ 2 tanks × 800 m³) | 24 – 32 t | ≈ 1.7 – 2.2 t | ≈ 20 – 27 t |
| 3,200 m³ (≈ 4 tanks × 800 m³) | 48 – 64 t | ≈ 3.4 – 4.5 t | ≈ 41 – 54 t |
| 5,000 m³ (larger circuit) | 75 – 100 t | ≈ 5.3 – 7.0 t | ≈ 63 – 84 t |
The formula behind these numbers is in Section 1. For a firm quote, tell your supplier your total tank volume and target concentration — they should return an initial charge and a make-up programme, not a guess.
1. The Carbon Concentration in Your Circuit
Most CIP and CIL circuits operate with a carbon concentration of roughly 10–25 g of carbon per litre of slurry (10–25 kg per cubic metre of tank volume). The right point in that range depends on your ore grade, leach kinetics and whether gold is loaded in a separate carbon-in-column (CIC) circuit. A common starting design point is around 15–20 g/L.
Once you know your total tank volume (in litres) and your target concentration, the initial charge is simple:
Initial carbon charge (kg) = total circuit slurry volume (L) × carbon concentration (g/L) ÷ 1000
Example: 4 tanks × 800 m³ each = 3,200 m³ = 3,200,000 L. At 15 g/L, the initial charge is about 48 tonnes. At 25 g/L it rises to 80 tonnes — a real budgeting difference, which is why the design concentration is worth getting right.
2. Carbon Density and Tank Loading
When you order carbon, remember it is bought by weight but installed by volume. Gold-grade coconut shell GAC typically has a bulk density around 0.45–0.52 g/cm³ (450–520 kg/m³), which means one tonne occupies roughly 2 m³ of settled bed. Check the density of the grade you buy — it affects both freight cost and how much carbon physically fits into each vessel.
3. Regeneration Losses and Make-Up Tonnage
Carbon does not disappear — but it does degrade. Every pass through screening, pumping, elution and the regeneration kiln grinds away a little material, and fines that escape the screens carry adsorbed gold with them. Typical operating experience is 5–10% make-up carbon per month of total in-circuit inventory — in daily operation that is roughly 0.15–0.3% of inventory per day, the working band for a well-run CIL plant. Aggressive regeneration or soft carbon pushes consumption toward the upper end of the band.
This is where hardness pays for itself. On a 50-tonne in-circuit inventory, the difference between 5% and 10% monthly make-up is 2.5 tonnes of carbon per month — roughly 30 tonnes a year. At current gold-grade GAC prices, that is a six-figure annual line item on a mid-size plant.
4. Specific Consumption Per Tonne of Ore
For planning and budgeting, plants often track carbon consumption per tonne of ore milled. Depending on grade, grind, regeneration efficiency and hardness, consumption commonly falls in the range of 0.05–0.3 kg of make-up carbon per tonne of ore (50–300 g/t). A 2,000 t/day plant at the middle of that range uses roughly 100–150 tonnes of make-up carbon per year.
Track your own number for six months — it is the single most useful figure for negotiating supply contracts, because it converts directly into annual spend.
Buy carbon on consistency, not on the best number in a brochure. If hardness or iodine drifts between batches, your consumption climbs silently — and your budget is the first thing to notice.
Putting It Together: A Quick Worked Example
- Circuit volume: 3,200 m³ → initial charge ≈ 48–64 t at 15–20 g/L
- Monthly make-up at 7%: ≈ 3.4–4.5 t/month
- Annual make-up: ≈ 41–54 t
- Plus a strategic spare of 1–2 containers held at port or mine
That is a practical annual carbon programme for a mid-size West African CIL plant — and a good basis for a supply agreement with firm pricing and guaranteed batch consistency.
Field Questions from West African Gold Plants
Work from your tank volume, not from the tonnage of ore. For a 1,600 m³ circuit at 15–20 g/L you need an initial charge of 24–32 t. Add roughly 5–10% of inventory per month as make-up, and keep one buffer container in-country while the next shipment is at sea — running a CIP/CIL circuit down to zero inventory is far more expensive than holding one spare lot.
Yes. Worked examples in the gold carbon industry routinely keep 1–2 containers at the port or mine to cover sea freight, port clearance and inland haulage. Standing monthly resupply from a single supplier keeps the grade consistent, which matters more than shaving a few dollars off one container.
Moisture is part of the spec. Gold-grade carbon should ship at ≤5% moisture as packed (PE-lined bags and pallet wrapping keep it that way on a humid sea leg). Ask for the COA moisture value for the exact lot, and agree whether the contract price is on an as-packed or dry basis before you sign.
Need Help Sizing Your Carbon Programme?
We supply gold-grade coconut shell GAC (mesh 6×12 / 8×16 or 3×6 mm, iodine 1000–1300 mg/g, hardness ≥98%) factory-direct from our plant in Longyan, China — produced and tested against the key requirements of YS/T 3038—2020 (Granular Activated Carbon for Gold Production), with a COA on every batch and bulk pricing for annual programmes. Tell us your circuit volume and we will work through the numbers with you.
Request a Quote →FAQ: Carbon Consumption for Gold Recovery
It depends on circuit size, ore grade and carbon losses. A mid-size West African CIL plant (around 1,000–2,000 tpd) typically holds 30–40 tonnes of carbon and needs roughly 5–10% of inventory as monthly make-up — so about 1.5–4 tonnes of new carbon per month. See the worked example in this guide for the full calculation.
Most CIL circuits run 15–25 g of carbon per litre of pulp (roughly 15–25 kg/m³), depending on gold grade and retention time. The initial charge is usually set at the design concentration, then maintained with routine make-up as carbon is lost to attrition, elution and gold-room losses.
Typical carbon consumption is 50–300 g per tonne of ore (0.05–0.3 kg/t), driven by attrition (fines), elution losses and gold-room handling. A harder coconut-shell GAC keeps consumption at the lower end of that band — a 2% hardness difference can mean nearly a tonne of make-up carbon a year in a 2,000 tpd plant.
Track your carbon inventory monthly: measure losses to fines, elution and the gold room, and replace what is lost to hold your design concentration. If you don’t have data yet, budget 5–10% of inventory per month and adjust after the first few months of operating data. Standing monthly resupply from one supplier keeps the grade consistent.