Great progress being made here - the project looking better by the minute.
On my understanding the economics of a rejuvinated Cobra (Gravelotte) along traditional lines - i.e., using hand sorting - already looked pretty robust in the current climate.
So it's mouthwatering that Gravelotte appears so amenable to the application of modern sorting technologies.
In the 1960's, as we're told, it was the largest mine of its type in the world (total recorded emerald production from 1929-1982 ~113 million carats). The processing circuit was, however, extremely labour intensive at the sorting stage - indeed, employing over 400 sorters at its peak.
Hand sorting at its best I believe will deliver about 75% of gems from the throughput material.
That's after several passes. And while requiring vigilant security.
Enter Optical and XRF technologies.
Trials are still underway, but the yields have this little black duck jumping out of his seat.
Have a look at the section (p.2) on X-Ray Fluorescence Sorters:
Recently completed XRF test work with a leading manufacturer of XRF sorters produced excellent recovery results (detected 100% of the emeralds in the test parcel) in addition to a high efficiency for the final concentrate (less than 3% of the test parcel reported as concentrate). The XRF machine showed excellent durability and Magnum have been advised that it requires low maintenance. The machine is also, very importantly, capable of achieving this high recovery and concentration at high throughput levels.
And this with vastly reduced risk of onsite losses! (All of the mechanical sorting technologies deliver the concentrated emerald material into locked safe boxes as part of the process.)
After all this work, the processing circuit is pretty much spelling itself out.
And the beauty of it is that it's so simple.
The physical characteristics of the emerald bearing material at Gravelotte are now well understood. Optimal crushing size has been determined; it's plain a trommel will help concentrate the material; and that mechanical sorting is going to work (spectacularly!) well.
"Well done!" to the blokes on- and off-site who've got us to this exciting inflection point in the Company's evolution.
MGU Price at posting:
4.0¢ Sentiment: Buy Disclosure: Held
