PERU - In an attempt to eliminate the use of mercury by artisanal gold miners, a Peruvian engineer has patented a small, cheap to operate, cylindrical machine. According to reports, gold-bearing slurry and biodegradable chemicals are fed into the machine. With the aid of centrifugal motion, the gold rises to the surface on bubbles. The concentrate can then be smelted. The machine may be capable of collecting 95% as much gold compared to using mercury.
About 20% of the gold produced in Peru comes from artisanal operators. Widespread use of this new machine could significantly reduce mercury contamination to rivers and streams, thus avoiding costly health problems.
The market for "green" gold, that produced without toxic chemicals or societal upheaval, commands a 10% to 15% premium among eco-aware buyers.
Sources http://goldnews.BullionVault.com/user/Goldbug and others.
(Editor's note: I am familiar with both centrifuges in gravity circuits and flotation cells. Perhaps this is a practical application of a combined technology. - M.S.)
Comments
John Pursel
Marilyn a few years ago I invented the use of a centrifugal concentrator ahead of flotation for the removal of heavy minerals from a feldspathic sand.
This reduced flotation from four to two stages thus saving immensely on capital and operating costs.
I found it odd that no operator in this industry had ever looked at doing this. I know this to be the case as I was having my samples assayed by a lab in North Carolina which is the centre of that industry. Lab staff were quite startled by this approach.
Robert Hilker
Floating gold has been a sluice box or screening plant loss in North America placer gold camps since the early 1854 gold rushes. The fine gold loss generaly has been estimated tu be as high of 25%-35%, or recovery of total gold of 65%-75%. The problem is the wash water carrying the fine gold to the gravity plant tailings. The method desribed and patended by a very clever and innovaited engineer is terrific- Congradulions ! I am a P.Eng. and have worked on placer gold projects for the past 40 years and am still leaning the trade. I would like to learn more about this method from the Peruvian Engineer. Would the Canadian Mining Journal please forward to me any contact or technical information of this method? Thanks(RGH)