RE:RE:RE:RE:RE:Another dose of reality..LovesAU wrote: .
My biggest problem was achieving a true estimate of actual grade. You were high consistently- miningman was low but very close. My problem was if in fact PVG was cherrypicking/high grading- where was the actual average grade gonna land? We now know at best it's 8g exactly half the grade this company used to sell stock. That's a helluva miss and certainly not just a mistake.
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Loves ,I am sure that you will not object to a correction / clarification to this statement of yours. The mouth breathers might choke, but they'll get over it. I have tried to explain on a couple of occassions that activities at Brucejack over the last few years have not included high grading in the normal sense , but rather very selective cherrypicking of stoping blocks.
In the Q+A session of this last dog and pony show , Joe O made two very revealing comments....... almost throw away comments to the general public , but extremely revealing to me. First when asked, How many stoping blocks are being worked today ??? his answer was " Half a dozen". Then when asked hoiw many stopes were mined out in 2019, the answer was 67..
Now cast your mind back 10 months or so, and recall the idea that development tates were being increased from 420 , to 700 to 1000 metres per month in order to increase the number of working stopes , to improve blending ability , give the miners more flexibility, yada yada yada. At that time there were 6 of 7 stopes in production and the goal was get to 15 or 18. There was even 42 reported as being in various stages of development.
I always thought 1000 metres a month was an extremely aggressive target, but I agree that more working stopes is a major operational improvement. And here we are, 8 or 9 months later with zero improvement to show for it!!! WTF is going on here??
Total develpoment for the year was reported 937 metres per month or 11,244 meters. The ramp from 1200L to 1080 L will have been 800 metres , plus maybe 200 metres for sumps and remucks , so 10,200 metres of stope access. Milled ore was 1.3 million tonnes so development per stope averaged 127 metres per stope. This is about twice what I would have expected based on design stope geometrr previously published..
To me this is confirmation of what I have suspected for some time. Despite Paths assertations that the miners have no choice but to follow a pre determined well thought out stoping sequence, they have been developing at a rate double what is required in the short term , to give themselves flexibility to temporarily ignore the 4 , 5 and 6 gram stoping blocks and in order to maximise short term ounces , only mine the hi grade 9 . 10 and 12 gram stopes with some low grade development muck thrown in..
The other interesting number is that tonnage per stoping block appears to be 19,400 tonnes per stope. This is very low for blasthole mining, but it is what it is.
However if my estimates of stope development rates is anywhere close , then there are about 67 stopes sitting there , already developed and test drilled adequately to suggest they are all sub 8 grams....... anything better would have been mined
So then tie this in with Joes report that stope development in H1 is to be essentialy suspended in order to focus on leteral development towards the Brucekack fault and towads the east, with stope development restarting in H2 2020. It now becomes clear where the mill feed for H1 is coming from......developed stopes that nobody liked the look of in 2019.
Then add in the start of reverse circulation stope drilling in Q2. This is I believe a new idea at Brucejack. This will be considerably more expensive than just assaying the blasthole cuttings which suggests they need additional gelogical info to select which ones of the low grade stopes need prioritizing as mill feed.
There are additional comments I can make bit we'll save them for a while