TECH REPORT - 2019 - ore regrind - better gold recoveries
2019 Tech report - page 110 -
It describes primary ground ores to a mesh size of - 74 micro meter = 200 mesh.
EXCERPT -
Whole-ore cyanide leaching at a primary grind P80 of 74 µm resulted in low recoveries
In the 2019 Tech report - page 112 -
It describes how the ores go through a regrind - 20 micro meters = 400 mesh.
EXCERPT -
" An analysis of the gold assays obtained from these test results indicate that the conditions required to achieve high gold extraction from the concentrate are a regrind size P80 of less than 20 µm and a TOC content of less than 0.5%. Average gold extraction values of about 94.5% were attained, with individual recoveries as high as 98.6%, "
So, what does this mean ?
It strongly suggests the gold is still in a matrix of graphitc ores even at 200 mesh.
Then, suddenly if a regrind is introduced to take it 400 mesh = boom = gold is imparted.
This Extraction report by McClelland - inserted into the 2019 Tech Report -
reveals a standard extraction is used.
But... where i find there to be an issue is wehat i was referring to in prior post.
It's simply switching up the regrind to 400 mesh and inserting this milling to the initial ore grind phase ( primary ) to facilitate the same gold impartation but... at same time - facilitate all the more
floated graphite during the clean water concentrate skim -
Why creatre an extraction flow sheet with an initial 200 mesh clean water float if, no gold is imparted ? lol It becomes a useless phase....
Grindign trhe ores from the get go to a 400 mesh - imparts the gold and gaphite.
= potential higher recoveries of graphite in clean water
while the current extraction flowsheet - the first phase of 200 mesh float does nothing really
and goes off to the 2nd sulpher phase - the noff to a regrind of 400 mesh -
In short... just mil lthe ores to 400 mesh -
Impart graphite - send off to the sulpher acid - cancel the regrind - and off to the final float with a
3.5 or less concentrate and a TOC - as mention in prior post of less than 1%.
Tech report proves my theory that a finer ore grindis key to unlocking the gold from the
graphitic ores.
To the poster who is concerned with more delays if graphite was ever considered...
Well... i'd say it a simple - swirtch up - of the regrind phase
simply insert this finer grind at the primary grind = create a 400 mesh.
Not hard to do - but will they...lol
If they did... perhaps mpore graphite would be captured instead of dissolved.
2019 TECH REPORT
https://www.spanishmountaingold.com/site/assets/files/3364/spanish_mountain_gold_-_technical_report_-_20191202.pdf
MESH SIZE CONVERSION CHART
https://www.sigmaaldrich.com/chemistry/stockroom-reagents/learning-center/technical-library/particle-size-conversion.html
There... i'm now content with the proving of a finer grind... wink.
If poor recoveries were seen with 200 mesh it points to the gold was still in the 200 mesh size.
Which also proves gold imparts at the 400 mesh .
Which might also prove that - if it imparts at the 400 mesh - what could be captured in gold
at this clean water 1st phase ?
I'd be employing some detergent to eliminate the static / surface tension
drop the gold to the bottom and skim the graphite .
It could support more graphite is pulled and even if gold was still in the water...
It might mean much less acid wirth second concentrate phase and less burden on the final float.
400 mesh... baby...lol
Cheers....