# Activated Carbon Dosage in CIL Plants: A Practical Operating Guide > Source: https://www.yelicarbon.com/blog-activated-carbon-dosage-cil-plant.html Getting the carbon concentration right — and keeping it right — is one of the highest-leverage operating levers in a CIL plant. Here is a practical framework. **By the YELI Technical Team** · Updated August 2026 · 7 min read In a carbon-in-leach (CIL) plant, the carbon concentration in the tanks is not a "set it and forget it" number. It drifts down through attrition, elution losses and regeneration — and when it drifts, gold recovery drifts with it. This guide covers how to set the dosage, how to keep it in range, and what to monitor so the carbon — and the gold — stay where they belong. ## 1. Setting the Initial Charge The starting point is the target carbon concentration, typically **10–25 g of carbon per litre of slurry**. Higher concentrations give faster gold pickup but cost more in inventory and can increase screen loading and carbon abrasion. Most CIL circuits are designed around 15–20 g/L. Initial charge = total slurry volume × target concentration. For a 4 × 800 m³ tank train at 15 g/L, that is about 48 tonnes of carbon to load the circuit for the first time. Two practical points at startup: charge the carbon gradually (a full dump at once can flood the screens), and confirm the actual concentration by sampling each tank after charging — volumes and densities on site rarely match the design exactly. ## 2. The Daily Dosage Routine Once the circuit is running, carbon is lost every day in small amounts — through screen overflow, elution losses, kiln attrition and carbon-in-fines. The operating routine should be: - **Sample carbon concentration per tank, daily or shiftly.** A simple displacement or volume measurement tells you if the inventory is holding. - **Log make-up carbon added** — weight and date. This gives you the consumption trend that drives your purchasing. - **Watch the leach profile.** If gold in the last tank's tail solution climbs, concentration may have dropped below the design point. Make-up is usually added in small daily or weekly doses rather than big monthly dumps — steady-state inventory management beats feast-and-famine. ## 3. Regeneration and Its Cost Carbon is stripped and regenerated on a cycle (often weekly to monthly, depending on loading). Each regeneration pass restores activity but costs a little carbon to attrition. The two levers are: - **Regeneration frequency** — regenerate before activity collapses, not after recovery has already dropped. - **Carbon quality** — a harder carbon (≥98%) survives more regeneration cycles, so your inventory lasts longer and make-up demand falls. Track "cycles survived" for your carbon. Coconut shell GAC typically withstands many more kiln cycles than softer coal-based grades — another reason gold plants standardize on it. ## 4. What the Numbers Should Look Like Healthy CIL operations typically see **5–15% monthly make-up** of total in-circuit inventory, and specific consumption of roughly **50–300 g of make-up carbon per tonne of ore milled** — with the lower end achievable on hard, well-managed circuits. If your consumption is above the range, check carbon hardness, screen efficiency and regeneration temperature before blaming the ore. > Carbon dosage is not an expense to minimize — it is a variable to control. The plant that holds its concentration steady recovers more gold with less total carbon than the plant that swings between over- and under-dosed. ## 5. Monitoring Checklist for Plant Managers - ☐ Carbon concentration per tank, daily - ☐ Make-up weight and date logged - ☐ Tail solution gold trend (early warning of under-dosing) - ☐ Screen efficiency — fines and oversize both cost money - ☐ COA of every delivered lot — verify hardness and iodine match the spec you designed around ### Steady Supply for Steady Circuits We supply gold-grade coconut shell GAC (6×12, iodine 1000–1300, hardness ≥98%) factory-direct with COA per batch — so your dosage plan is never hostage to a variable supplier. Ask about annual programs with firm pricing. Request a Quote → (https://www.yelicarbon.com/contact.html#quote-form) ## FAQ: Activated Carbon Dosage in CIL Plants What is the typical carbon concentration in a CIL plant? + Most CIL circuits run 15–25 g of carbon per litre of pulp (roughly 15–25 kg/m³), depending on gold grade, ore throughput and retention time. The initial charge is set at the design concentration, then maintained with routine make-up as carbon is lost to attrition, elution and gold-room handling. How much make-up carbon does a CIL plant need? + Budget 5–10% of carbon inventory per month to start, then adjust on operating data: measure losses to fines, elution and gold room, and replace what is lost to hold your design concentration. A harder coconut-shell GAC keeps monthly consumption at the lower end of that range. How do I calculate the initial carbon charge? + Multiply your design concentration (e.g. 20 g/L) by the total pulp volume of your tanks. For a 5,000 m³ circuit at 20 g/L that is 100 tonnes of carbon for the initial charge. Then add a working margin for losses during commissioning, and confirm the grade and sieve cut match your interstage screens. How often should I check carbon dosage? + Daily: carbon concentration per tank and tail solution gold trend (an early warning of under-dosing). Weekly: make-up weights logged, screen efficiency (fines and oversize both cost money). Every delivery: verify the COA — hardness and iodine must match the spec your circuit was designed around. ### Related reading - How Much Activated Carbon Do You Need for Gold Recovery? (https://www.yelicarbon.com/blog-how-much-activated-carbon-for-gold-recovery.html) - Why Activated Carbon Hardness Matters in Gold Recovery (https://www.yelicarbon.com/blog-why-carbon-hardness-matters-gold-recovery.html) - Gold CIP/CIL Grade Activated Carbon — Full Specification (https://www.yelicarbon.com/product-gold-cip-cil.html) - Why Coconut Shell Carbon Dominates Gold CIP/CIL Plants (https://www.yelicarbon.com/blog-gold-cip-cil.html) - Activated Carbon Price per Ton 2026 (https://www.yelicarbon.com/blog-activated-carbon-price-per-ton.html) - Gold Carbon Supply for Mali (https://www.yelicarbon.com/activated-carbon-mali.html) - Gold Carbon Supply for Burkina Faso (https://www.yelicarbon.com/activated-carbon-burkina-faso.html) Browse all activated carbon products & request a quote → (https://www.yelicarbon.com/products.html)