Carbon regeneration is the thermal treatment of activated carbon to restore its gold-loading capacity after extended use. Carbon is heated in a rotary kiln to 650–750°C in a steam atmosphere, which burns off organic foulants and pyrolyzes inorganic residues that had reduced the carbon's gold-adsorption capacity. After regeneration the carbon returns to the adsorption circuit.
Why Regenerate
Activated carbon loses adsorption capacity over weeks to months as it accumulates organic foulants (oils, flotation reagents, dissolved organic matter from ore) and calcium scaling. Without regeneration, the carbon inventory needs to be replaced — expensive. Regeneration restores ~90% of fresh-carbon activity at a fraction of replacement cost.
Process Steps
(1) Acid wash with HCl to remove calcium carbonate and base metals. (2) Water rinse to neutral pH. (3) Drying to remove moisture. (4) Thermal regeneration in a rotary kiln at 650–750°C with steam injection for 30–60 minutes residence time. (5) Quench in water; the regenerated carbon is screened to remove fines and returned to the adsorption circuit.
Equipment
Rotary kilns (electrically heated or natural-gas fired) at scales from 10 kg/h pilot up to several hundred kg/h industrial. KCA has delivered 25 kg/hr and 75 kg/hr regen units to multiple projects.
Carbon Fines
Regeneration generates some carbon fines (broken particles below screen size). These fines retain significant gold and silver value but can no longer return to the adsorption columns. KCA's patented Carbon Converter processes these fines — recovering up to 99% of the contained gold and silver as a fine ash for downstream smelting.
Have a project that involves Carbon Regeneration?
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