Garry Foord (GM of Mines) indicated stoping was proceeding on the 840 and 790 Levels and we saw them charging blast holes on the 745 Level, stoping between the 745 Level and the 730 Level above it. These would have been fired shortly after we left. So stope ore is coming from the 840, 790 and 745 Levels, with development ore from the 730 level. Garry said they will start stoping from the 730 Level this week as well. It's all go, go, go!
We didn't have time to visit the processing plant (too much fun underground!). I didn't ask how much was stockpiled at the processing plant. The plant processes about 800 tonnes a day, so any stockpile at the plant is processed during the week.
The ore piles shown in the video are on the Warrior pad - Garry pointed out that the piles are set up in different grade ranges with coloured marker drums to aid the truck drivers when dumping -green is 1 - 5 g/t Au (Low Grade) -yellow is 5 - 10 g/t Au (Mill Grade) -red is 10 -25 g/t Au (High Grade) -pink is 25 - 100 g/t Au (Very High Grade) -brown is above 100 g/t Au (Spectacular Grade). These piles are then blended for transport to the processing plant.
The sampling is not grab sampling, it's a systematic set of traverses over each pile, collecting six samples of 3 kg each, which are crushed and blended to get an average 20kg sample, which is then split down to get about 3 kg sent for assay.
All the material above 1 g/t is sent to the Mil eventually, depending on how it is blended. The Mill performs best in terms of gold recovery in the 5 to 10 g/t range, so they blend to get this range. Remember at current prices and exchange rates (say US$900 an ounce and A$1 = US$0.95) a gram of gold is worth A$30. Their processing costs are about $30 a tonne, so 1 g/t rock that has to be brought to surface anyway is worth processing to get a break-even ounce that offsets the fixed overheads to lower the average cost per ounce.
Cheers, Sid
CTO Price at posting:
0.0¢ Sentiment: Buy Disclosure: Held
