Copper Future - Part 231 Jul 2020 08:17
The rest of the drilling results will be produced during the summer and autumn, which will be followed by an updating of the PEA which will redefine all the resources. They expect to move “Inferred” resources into the “Measured and Indicated” categories, plus they hope to expand the global resources with the possible discovery of additional blocks of ore. At the same time they are performing pilot plant work on the magnetite skarn ore with ammonium thiosulphate (ATS), to see if this matches the bench scale results for gold recovery. If successful, they will move a small pilot plant onto the mine site to test gold recovery and confirm the laboratory testwork results.
The operation will be to crush and grind the ore, and leach with ATS, which still leaves the copper in the ore for recovery. In fact, the ATS looks like it does not remove copper compared with the cyanide route, so copper recoveries should ultimately be increased. It is worth noting that the ATS treatment route is particularly environmentally friendly.
Through this drilling work, although focussed on the gold zone, copper will also be under the spotlight, and they are expecting to move this up as well through 43-101 JORC compliant resources. The autumn period will be one of stepping back, looking at all the results, and making decisions driven by the geology, mine engineering and metallurgy, together with the economics of the metals market.
Before moving on, we also talked about the channel sampling results. These looked very encouraging, with high copper levels at surface. The director commented that we should never forget the copper and the value there.
We then moved over to the longer term, and for this we need a little science for it to be explained, and I hope understood. So here’s an interlude from the conversation with my very simple explanation:
The crust of the earth is relatively thin compared to the mantle and the core. The mantle is of course hot, and liquid as magma rises through gaps between the continental plates, as witnessed in areas of volcanic activity, and over hundreds of millions of years this flow brought metals to the surface from the core. “Porphyritic” is the description meaning a flow of a type of potential metal hosting magma of deep volcanic origin, which then over time cooled and solidified. These flows often form into a large underground lake of magma (“magma chambers”) which separate in layers, according to different densities and phases of cooling. The liquid metals brought up in the magma of porphyritic origin at different times are responsible for creating rich deposits of copper, molybdenum, gold, tin, zinc and lead within the rock itself. But the fluids can also find ways towards the surface, where they solidify as veins.