DD Support Board and Research Team

[Dunphy777]

I am assuming that the silver and other values are contained in sulfides present in the ore. Back when these deposits were discovered, flotation was not a well known processing technology. It mentions in one of the reports that they used gravity separation initially and this wasn't very efficient. Later on they used flotation and actually reprocessed some of the original tailings. I could not find a picture of this centrifuge but it sounds like a small Knelson concentrator. A lot of scam companies are currently promoting these as a magic box that can recover just about anything. They can be very efficient for recovering free gold that is present in the process material but not too effective or efficient for recovering a sulfide concentrate. The specific gravity of the gangue and the sulfides probably 2.5 vs 5.0 whereas with quartz and gold it is 2.5 vs 17.5. These concentrators are usually operated in batches and the volume of the sulfides would require shutting them down very often to clean out the concentrates. With gold, they can often go 4 hours or so before it is necessary to clean out the gold.
There are too many factors that I don't know before I could give you a ball park cutoff grade for economical ore and I don't think the company will give us this information to do our calculations.