How to Compare Coconut Shell Gold Recovery Carbon Quotes: A Landed-Cost Method for CIP/CIL Buyers

By the YELI Technical Team - Updated October 2026 - 9 min read

Short answer: Comparing coconut shell gold recovery carbon on unit price alone is the fastest way to overpay. Three quotes only become comparable when the specification basis, packaging, container loading, delivery term, payment terms, MOQ and testing obligations are all normalised onto one landed-cost-per-tonne figure. The same 6×12 mesh carbon — iodine 1000–1300 mg/g, hardness ≥98%, platelet content <1.5%, apparent density 0.45–0.52 g/cm³ — can be quoted FOB or CIF, in 25 kg bags or 1,000 kg bulk bags, with roughly 15% difference in the tonnes that fit in a container. The lowest unit price is often not the lowest delivered cost.

Three quotes land in your inbox on the same afternoon: 1,180, 1,240 and 1,310. The obvious choice is the first number. In a CIP or CIL circuit that choice is where most procurement losses begin, because none of those three figures describes the same product, delivery or commercial risk.

This article splits each quote into cost lines you can compare one to one, then rebuilds them onto one basis — delivered cost per tonne of usable carbon at your plant gate. The method works the same for a 20-tonne trial or a 200-tonne order.

Why the cheapest unit price is rarely the cheapest carbon

A quote is a price for a specification, not a price for "carbon". Two suppliers can sit 120 USD per tonne apart and both be honest, because they are not selling the same thing. Before you compare, mark which of these lines is missing from each quote.

• Iodine number. Gold-grade coconut carbon is quoted at iodine 1000–1300 mg/g, per ordered grade, with a tolerance of ±50 mg/g (GB/T 12496.8 / ASTM D4607). A supplier who quotes "1000" when you specified 1150 is quoting a different product, not offering a discount.
• Hardness. Ball-pan hardness is quoted at ≥98% for gold CIP/CIL grade (GB/T 12496.6 / ASTM D3802). "High hardness" or an unqualified 95% is a different attrition budget. Softer carbon makes fines; fines pass the screens and leave the circuit carrying gold with them.
• Platelet content. Platelet-shaped particles screen badly, mat into layers and blind interstage screens. Gold grade is quoted below 1.5% platelet content, achieved by water polishing and de-flaking. If platelet content is not on the quote, assume it is not in the contract.
• Apparent density. The measured range is 0.45–0.52 g/cm³ (GB/T 12496.1 / ASTM D2854). Density decides how many tonnes fit in your container and how many kilograms sit in a tank of fixed volume. 10 m³ of carbon holds 4,500 kg at 0.45 g/cm³ and 5,200 kg at 0.52 g/cm³ — a 700 kg spread, about 15%, on identical volume.
• Moisture and ash. Moisture at most 5% as packed (GB/T 12496.4 / ASTM D2867) and ash at most 5% (GB/T 12496.3). You pay ocean freight on water, and a wet load can push a container past its declared net weight.
• Mesh and cut. 6×12 mesh (1.70–3.35 mm) is the gold recovery standard (GB/T 12496.2 / ASTM D2862). 8×16 mesh and 3×6 mm cut carbon serve other duties and cannot be compared per tonne with 6×12 without adjusting for how the particle size behaves in your tanks and screens.
• Standard and certification. The specification should name YS/T 3038—2020, the standard for granular activated carbon for gold production, and should state that a COA is issued for every batch rather than "on request".

Two quotes at different iodine grades, hardness values and platelet limits are two different products. The cheaper one may still be the right purchase for a different duty — but it is not comparable per tonne. If you are rebuilding the specification itself, start from the gold recovery carbon specification sheet and the purchase specification guide.

What must be identical before two quotes can be compared?

Write the comparison basis down before you open the attachments.

• Mesh size and cut method — 6×12 mesh, 3×6 mm cut, or 8×16 mesh.
• Iodine grade ordered, plus tolerance — for example 1150 ±50 mg/g.
• Hardness value and the test method behind it — ASTM D3802 or GB/T 12496.6.
• Platelet (flake) content — target below 1.5%.
• Apparent density, measured in g/cm³ — not "typical".
• Moisture and ash limits as packed.
• Quantity basis — net dry weight or as-packed weight. A 5% moisture difference is 5 tonnes on a 100-tonne order, and you pay freight on all of it.
• Packaging — 25 kg laminated woven bags or 500–1,000 kg bulk bags, palletised or floor-loaded, bags included or charged separately.
• Delivery term and named port — FOB Xiamen, CIF Tema, CIF Abidjan, CIF Dakar.
• Payment terms — percentage advance, balance against documents, or letter of credit.
• MOQ and lead time, in weeks from order acknowledgement to vessel departure.
• Testing and documents — who pays for pre-shipment analysis, third-party inspection, COA and certificate of origin.

If one quote answers eight of those twelve lines and another answers all twelve, you are not comparing prices. You are comparing how much risk is left with you.

Two of these three quotes are not selling what the buyer asked for, and the third is selling the right grade at the wrong delivery basis. None can be ranked on unit price yet.

Normalising three quotes onto one landed-cost basis

The conversion has one formula and two corrections:

Landed cost per tonne = FOB or ex-works unit price + origin inland handling and port charges (if not included) + ocean freight + marine insurance + destination port charges + inland haulage to your plant + testing and inspection + the financing cost of the payment terms + a reserve for storage and demurrage.

Net cost per effective tonne = landed cost per tonne ÷ (1 − your allowance for fines, dust and attrition losses you will not recover).

First correction, the freight denominator: when freight is quoted per container, divide it by the tonnes actually loaded, not by nominal capacity — density and packing form decide that number. Second, the effective-tonnage adjustment: carbon that arrives at 5% moisture, or attrites into fines within months, is not the tonnage you paid for. Use your own attrition history; if you have none, run a trial before committing to an annual contract.

Worked example: 100 tonnes of 6×12 mesh gold carbon, delivered to a plant 900 km inland from Tema, ocean freight at 2,600 USD per 20-foot container. The figures are illustrative and exist only to show the arithmetic. They are not YELI prices, and your freight, insurance and bank charges will differ.

Read the last three rows together and the picture changes. On headline numbers Quote C looks cheapest by a wide margin, Quote B's CIF figure looks alarming next to a 1,120 FOB price, and Quote A looks like the expensive one. Normalised, the spread is 1,494 to 1,520 — about 1.7%. These three are effectively quoting the same delivered price, so the decision should not be about price at all.

Two mechanics drove the reversal. Quote A's carbon at 0.52 g/cm³ loaded 12.5 tonnes per container against Quote C's 11.1 tonnes at 0.46 g/cm³ — the same ~24 m³ of stowage, eight containers instead of nine, 26 USD per tonne of freight saved. Quote B's higher-looking CIF price already contained the freight and insurance the other two billed separately. Quote C's low unit price was offset by a nine-container freight bill, the costliest payment terms and a specification one iodine grade lower than requested.

Why does apparent density change the tonnes in your container?

A container is filled by volume, not by weight. At 0.45–0.52 g/cm³, granular coconut carbon is far lighter than a 20-foot container's payload limit, so the binding constraint is stowage volume and how well the packing form fills it.

That arithmetic is a straight conversion from the measured density range. What a named container really carries depends on usable stowage volume and stuffing, so ask your supplier to compute the load against your container volume using the density measured on the batch COA.

Packing form interacts with all of it. 25 kg laminated woven bags mean 40 bags per tonne, stacked by hand, with corner voids that are hard to fill and bags that settle in transit. Bulk bags of 500–1,000 kg fill more of the same void space and cut stuffing labour, but they need a forklift at the receiving end, and an opened 1,000 kg bag must be used or resealed against humidity. Palletised loads consume stowage volume and add wood treatment and marking cost; floor-loaded bags fit more tonnes in the same box. Get the loading assumption in writing, because a "cheaper" bagged quote can lose more in freight per tonne than it saves in bag cost.

Density also drives what happens after unloading. A 10 m³ adsorption tank holds 4,500 kg of carbon at 0.45 g/cm³ and 5,200 kg at 0.52 g/cm³. If your circuit targets a carbon concentration of 10–25 g/L of slurry (Industry-typical; not a YELI process commitment.), that density difference changes how much carbon your tank inventory represents, and how much adsorbing surface meets the pulp.

FOB or CIF — and which port? Where the hidden cost sits

FOB means you nominate the freight forwarder and risk transfers once the cargo is on board at the load port. You see the real freight rate, you can consolidate with other inbound cargo, and you control the routing. The trade-off is administration: you carry the booking and the insurance.

CIF means the supplier arranges and pays freight and insurance to a named destination port. It is one number and easier to budget, but it hides the freight rate, and a padded freight line is invisible inside a total price. Two habits fix that: ask for both FOB and CIF prices on the same goods so the implied freight is visible, and ask for the bill of lading and freight invoice as a condition of the CIF price.

CIF does not include destination terminal handling, agency fees, documentation, customs clearance, port storage or inland haulage. On many West African routes those destination charges add 5–12% to the landed value (Industry-typical; not a YELI process commitment.), and they are the line most often missing from a buyer's budget.

The named port is not a detail. CIF Tema, CIF Abidjan and CIF Dakar are three different prices, with different transit times, direct-call or transhipment patterns, congestion levels and free-time allowances at the terminal. Add detention and demurrage to the risk column: if documents lag the vessel or clearance stalls, the container accrues daily charges while your carbon sits in humid port air. For West African plants, importing activated carbon through Dakar, Abidjan or Tema starts with choosing the gateway your logistics partner can actually clear.

Payment terms, MOQ and lead time are cost lines too

Payment terms are a price, even when negotiated separately. A 30% advance with the balance against a bill of lading copy ties up your working capital from deposit to shipment. A letter of credit at sight costs issuance and amendment charges and takes longer to open; a confirmed LC adds a confirmation commission. An open-account request from a first-time supplier usually gets priced back into the unit rate. Convert terms into a number — the financing line in the landed-cost table — and compare totals, not clauses. The mechanics of payment terms when buying activated carbon from China are worth reading before you accept a first-offer structure.

MOQ is a cost line in the opposite direction. A 20-tonne MOQ at a small premium can beat a 100-tonne order you cannot store: carbon in a humid shed picks up moisture, and woven bags lose strength when stacked for months.

Lead time is the most expensive line on the sheet, because it is the only one that can stop the plant. Get it in weeks, from order acknowledgement to vessel departure, with transit quoted separately. A three-week delay on a plant running low means falling carbon concentration in the adsorption tanks, and the difference shows up in the tailings, not on the invoice. If you are already seeing that pattern, tailings gold loss diagnosis is the faster diagnostic. Ask when the production slot is booked, not just how long production takes: around Chinese New Year and peak shipping season, both factory slots and vessel space tighten.

Test, document and inspection fees that show up after you sign

The COA is the first document to pin down. YELI issues a COA with every batch, covering iodine, hardness, platelet content, apparent density, moisture and ash with the method number for each. Any quote that promises "COA on request" or "COA for the first container only" is handing you the testing bill later. Ask for a COA sample with your quotation so you can see which parameters and methods will be reported, and read how to verify a gold carbon COA before you accept the first one at face value.

Then decide who pays for independent verification. Third-party sampling at the load port — SGS, BV or Intertek — is quoted per lot and adds several days before the vessel cut-off. It is cheap insurance on a first order and largely unnecessary once a supplier's record is established. What matters is doing it before the booking.

Set up two things in the contract. First, retained reference samples: one sealed, jointly signed sample per batch, held for the warranty period. If a dispute arises at destination, that sample is the arbiter, not a photograph of a bag. Second, the full document set: commercial invoice, packing list, bill of lading, certificate of origin, COA, non-wood packing declaration or ISPM 15 marking, MSDS and the insurance certificate for CIF shipments. A missing certificate is not a paperwork problem; it is a port storage charge and a demurrage clock. The full list is on our documents and certifications page.

One more point on test values. Iodine, hardness, platelet and density are routine and on the COA. K-value and R-value are measured by an independent third party and reported with the COA on request; we do not publish guaranteed K or R figures, and any supplier who guarantees a precise K or R number should be asked for the test report behind it. The ASTM testing standards guide explains which method applies to which parameter.

Which differences are real cost, and which are just clause packaging?

Three questions sort every difference between two quotes:

1. Does it change the carbon that arrives? If yes, it is a specification difference and it is real.
2. Does it change what it costs to move that carbon to your gate? If yes, it is a logistics or financing difference and it is real.
3. Does it only change who writes the cheque, or how the number is presented? Then it is clause packaging — normalise it and move on.

The last piece of discipline is the RFQ itself. Leave these lines open and three suppliers will fill them in three different ways.

Frequently asked questions