How To Choose The Right Activated Carbon For Gold Recovery

1. Clarify the requirements for gold recovery process
* Process type: Determine whether it is heap leaching or carbon-in-slurry (CIP/CIL). Different processes have different requirements for the adsorption rate and strength of activated carbon.

* Solution characteristics: Gold recovery usually uses cyanide solution (such as gold cyanide complex), and it is necessary to ensure that the activated carbon is stable in an alkaline environment (pH 10-11).

2. Core performance indicators
Adsorption capacity:

* Iodine value: measures the micropore adsorption capacity. The recommended iodine value for gold recovery is ≥1000 mg/g (preferably CTC 55, CTC60 coconut shell activated carbon).

* Gold adsorption capacity: directly test the adsorption amount of Au(CN)₂⁻ (unit: g Au/kg carbon), requiring ≥3 kg/t.

Particle size:

* Common range 1-3 mm (too fine will clog the equipment, too coarse will reduce the adsorption efficiency).

* Slightly larger particles (2-4 mm) can be selected for heap leaching, and smaller particles (1-2 mm) can be selected for carbon slurry.

Hardness (wear resistance):

* High hardness (wear rate <5%) reduces powdering during transportation and mixing, and avoids gold loss.

Coconut shell charcoal is usually harder than wood or coal-based activated carbon.

Purity:

* Ash content <5% (too high ash content may release impurities, interfere with adsorption or contaminate the solution).

* Avoid metal impurities such as iron and calcium (may react with cyanide).

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3. Special requirements
pH adaptability: Need to withstand a strong alkaline environment (pH 10-12) to avoid the collapse of the activated carbon structure.

Regeneration capacity:

* After high-temperature activation and regeneration, the adsorption capacity needs to be restored to more than 80%.

* Activated carbon that can be reused 5-10 times is preferred to reduce costs.

Density: Apparent density 0.4-0.5 g/cm³ is more suitable for flotation separation.

4. Type recommendation
Coconut shell activated carbon (preferred):

* High hardness, high adsorption capacity, low ash content, suitable for long-term recycling.

* The disadvantage is high cost

Coal-based activated carbon (alternative):

* Low cost, but weak adsorption capacity and wear resistance.

* Suitable for short-term or low-concentration gold recovery scenarios.

Colin activated carbon can meet different types and requirements of gold recovery, providing strong support for the global gold recovery industry