I'm replying to my own post because I can't stop thinking about this ASX Release (thinking I must have misread it) and I've reread it to try to understand it. I now feel its worse than I thought because I studied it a bit more and found more info and made more logical connections:
Firstly, I missed this last time, but Figure 4 actually shows some grades and tonnages annotated to each Bulk Sample location (I just can't bring myself to use BS). (Would have been nice to have these annotations visible). So these annotations should logically represent the grades of the Bulk sample generated from sub sampling and lab analysis, but they are the grades from the Table titled Plant Recovered.
This merely confirms what I thought in last post that the ASX Release is suggesting that because the averages at the bottom of the two grade columns in the Table are similar that somehow that's good? Aka somehow that they got some correlation between what the actual lab analyses (from leaching of 1kg from 50kg taken somehow from the 15kg bulk samples) returned, to what gold Dore they recovered from the plant then divided back into the weights fed into the plant.
So, noting no discussion of how this (back calculation to derive the Plant Recovered grades) was done in JORC Table 1, I can only assume that they poured Dore from each Bulk Sample and then figured out that as a g/t contained in the 15tons from where it came through the plant.
Well I posted in my earlier post how tricky it is to get good results for sampling and analysing just the Bulk sample, especially the dual issues of first getting a representative 1kg sample from the 15tons, and then the possible losses and contamination in the crushing of that sample even in the lab and I also didn't discuss the amount of gold left behind after the leaching was completed?
Imagine how difficult it is to get that level of QC/QA for a bulk sample going through the plant: Look again at JORC Table 1 "Sub-sampling" last bullet which discusses the plant components it goes through and ask yourself could each separate bulk sample be put through that without cross-contamination and losses - noting you would literally have to pull apart and clean out the entire circuit before every bulk sample to be accurate.
What about the tails - what grades etc. There is just no way these poured Dore weights divided into the 15ton sample weights can return anywhere near accurate head grades that could be compared with lab analyses of poorly representative grab samples from the same bulk samples.
But even after all that, those are still just basic operational process and sampling issues a technician should understand, but I lose my mind with the basic underlying rationale behind this test and the conclusions drawn from the Table generated. This is the real issue here - competency - the fact that this nuggety issue is not recognised, that then the averages of the two grade columns can some how be compared when there is obviously such divergent individual results, and finally that because this comparison is somehow good.
It even amazes me some of the minor things, like for instance using a comma in the 2,04 g/ton, and the mixing of metric and imperial (grams and tons and g/t) and even in the Table the number of decimal points (one is an exact 10ton and the others all to 2 decimals, same with other columns - JORC actually defines (well certaimly for resources and reserves) the number of decimals according to the number of significant figures) and even though OGX don't operate with official JORC Resources, they are still legally obliged to release their numbers according to the JORC Code.
Sorry - I just can't get over this ASX Release - because somehow it trys to say that because 2.48 from the lab is close to 2.04 from the Plant Recovered and I just cant understand how that could be at all accurate? And wouldn't it be better to focus on plant recovery etc and say the plant recovered 80% of the gold or some such statement. I think you can understand why a process plant isn't used to sample and analyse head grade.
The plant should be used to see how well each component works on bulk samples, so sub samples from before and after each piece of equipment, and their rates of throughput are measured and a mass balance developed. Thats what should be releases and discussed. Isn't there a specialty plant manager onsite?
Who writes the ASX Releases and checks the statements? Note specifically the Competent Person statement says that the Information in the announcement is based on information provided by the CP - doesnt mean the CP actually made the statements and conclusions? Is the CP reviewing the statements and does he have the power to revise them?
In all honesty I hope I haven't missed something or got something wrong, and this is all only in my opinion so please make your own conclusions based on your own review.
KRUM
