AXG - Antipodes Gold [formerly GEL - Glass Earth]

[elZorro]

The AusIMM annual conference kicks off this weekend, and Glass Earth has a part to play there. No doubt there will be a few useful meetings.

I sent another email to Simon Henderson with a few questions, and he has again been helpful.

I asked how the GRUs were going on the placer permits:

SH: Placer results: you asked if the machines are going well, I’d answer with a qualified “yes”. They are highly sensitive units and must undergo weeks of calibration and tinkering before they’ll deliver. This is compounded by the ground we’re working: a far higher than typical fraction of feed is “undersize” (sub-10mm gravels which must be processed within the plant instead of being bypassed) meaning we must carefully regulate feed rates (one plant is currently being fed at 45 loose cubic metres/h, the other ex-Earnscleugh plant at around 55lcm/h). Also, a far, far higher than typical fraction of the feed is extremely fine clay which means our sediment ponds and recirculating water need intensive management and treatment to keep the plants running. Others have given up on similar ground but we believe we’re now a step ahead.

Simon is talking here about GRU#3 (doing about 45 m3/hr) and GRU#1 (doing 55 m3/hr). Both are at sites on the Drybread permit. The tricky ground may be helpful to the cause, it might have been out of favour in the past. I have read that in rivers, gold is often found on the top of clay pans, or in layers underneath them. So the presence of quite a bit of clay could also be good, especially if they're working the top of the permits and the test RC drilling gave better grades lower down. I'm not sure how the clay will be causing an issue with the pumps and settling ponds, maybe it blocks water filters.

Here's a very informative article on jigs, the primary recovery method GRU#1 uses, at least.

http://mines.az.gov/Publications/circ052jig.html

The video of GRU#1 (GEL website) shows the plungers working, and this method appears to be self-cleaning and less likely to block up with heavier minerals like ironsand. It's also good for fine gold, better than riffles. So if GRU#3 and GRU#1 are working similar grades, GRU#1, with its bigger capacity and the jig system, should do better. You'd probably be able to run it for longer without washing up the gold.