Would you comment on how fine (particle size distribution) & specifically the type of carbon!

Can you give some background information to your problem? As far as graphite, a naturally occurring carbon, is concerned, it has natural floatability and can be floated using kerosene, as a collector and pine oil as a frother. Add these during grinding and adjust pH to alkaline (7.5 to 8) domain before flotation. See if this serves your requirement.

The PSD information at the moment I don't have, but the top is just below 0.50mm. The idea of floating carbon is to roughly quantify the carbon content from carbon in pulp circuit tail. The carbon in use here is basically a medium activity carbon employed for CIP-Elution. Sometimes final tail residues gold content spikes. I suspect finer carbon small enough to pass through 0.50mm guard screen.

I've floated graphite, petroleum coke, and anthracite using conditions similar to those mentioned above. Balancing frother / collector dosing and cleaning stages permitted some control of concentrate quality. Re % solids for conditioning & flotation - have done this primarily at lower percent solids & that was ok in general. However, given nature of the feedstock - some petroleum coke feedstocks - conditioned at high % solids.

If your goal is to understand nature of carbon losses, should be able to get a indicative idea through flotation and some microscopy of the flotation product.

Have you tried a simple "reverse" gravity test? You could simply hand pan a little of your tailings with the aim of concentrating the light carbon fraction into the tailings.

The issue under discussion is a very thorny problem in the gold recovery industry. As the adsorption process with activated goes through many variable problem breaking the carbon to smaller size fractions. All the details suggested are good and tangible but at AGA (OBUASIMINE) we have decided to pass that carbon through a thickener to collect the carbon and send them to plant which have incinerators to burn and then we are charged treatments chargers and balance is paid to us calculating using 30 day average gold price.

We are using GOLDPLAT processing plant in GHANA for that.

As prospective essay try one under the following conditions: 100 g / t of kerosene or diesel oil plus 100 g / t of pine oil; pH range from 7 to 8.5; solid mass concentration below 25 %; 2 minutes of conditioning time. If necessary, add water glass (sodium silicate) as a silicate depressant (about 400 g/t).

Mineralogy & size distribution of the particle are the two main deciding factors in the processing of minerals. In your case, the fine carbon may be floated using kerosene or diesel in alkaline pH after removing -400 mesh particles from the slurry using panning. Sodium Silicate can be used as silicate dispersant & depressant. The dosage of reagents and conditioning time may be altered and compare the assays. Alternatively, one can see the results using M.I.B.C. both as collector & frother with less conditioning time (1/2 minute to 2 minutes).