G'day groundswell & OGX's -Agree 100 % with your comments
Re -"Dilution "
Problems with recovery were two fold .
1) Processing re liberation of gold is reputably in hand with finer micron crush from
hammermills recovery reported by the company to be in the 90% region & as
per recent announcement
samples are being verified independently.
( personally I will be rapt with 83-87%)
2)Dilution during extraction was a real concern & deserves further thought
as its very important-see older thread comments from self if interested.
Couple of points to consider.
1) The company is aware of this issue & as its been mentioned
several times as one
of the primary issues & clearly OGX are intent on being upfront with the market
regarding dealing with this important issue.
ASX/Media Release – 12 January 2018
Further Spectacular Grades from Pilot Hammer Mill
points of interest relevant to topic from above asx release -see below.
Quote-
In hindsight, OGX’s new management team believes it has been a combination of excessive
dilution during mining together with low recoveries from its existing gravity recovery plant that has continued
to struggle to recover the finer gold component of the ore.
ASX/Media Release – 28 December 2017
Spectacular Gold Grades Continue from Pilot Hammer Mill
Relevant paragraph from above in extract below.
Whilst the potential of Cascavel has always been exciting, the delivery of ounces has been elusive.
Numerous independent experts have visited site over the last 12 months attempting to crack the
code as to why visible high grades in the Mestre and Central zones have been unable to translate into
low cost ounces.
In hindsight, OGX’s new management team believes it has been a combination of excessive
dilution during mining together with low recoveries from its existing gravity recovery plant
that has continued to struggle to recover the finer gold component of the ore.
Further Spectacular Grades from Pilot Hammer Mill
OGX’s new management team are proving that it has been a combination of excessive dilution during mining,
together with low recoveries from its existing gravity recovery plant.
As a result of our recent successes" new ore extraction methods have successfully been implemented in the development drives" and a new low-cost blasting method has successfully been implemented in the stopes.
Very interesting to consider below
ASX/Media Release – 17 January 2018
Mestre Assays Show Bonanza Grades Up To 265g/t
Relevant to topic extract below.
Cascavel vs Norseman
Over the last 5 years, some comparisons have been made with Cascavel and the "G Ablett Senior" of narrow vein gold mines - Norseman in Western Australia.
Our production geologist
Leandro Ballarin who cut his teeth at Norseman also compares Cascavel to this incredible orebody.
Norseman pulled out a reported 6 million ounces of gold over 120 years without a JORC of any real shape or form until the mid-1990's.
Gold at Norseman was principally mined from narrow, north-south striking,
east dipping quartz veins.
The quartz rock appears similar to Cascavel quartz with visible gold a
common feature.
Mining was conducted on a
"more you mine the more you find" approach
where the old timers would follow the quartz vein.
Like Cascavel the factoring affect was very prevalent where the grade of a drill result
tended to
significantly underestimate the milling grade later.
Factoring at Cascavel for example can be as high as 20-30 times the
drill grade.
Cascavel is a
similar difficult orebody to calculate a JORC compliant resource because of the nuggetty nature of its narrow veins also.
Finding the answer to the million-dollar question of whether Cascavel could be another Norseman
will take several years of consistent results.
As we begin this journey of discovery,
we believe that the more we mine the more
we also will find, and the assay results today are another hint of Cascavel's potential.
In reality, there are very few mines in the world that boast these grades.
Back to topic
Other thoughts & considerations
Having four separate continuous high grade gold veining areas to extract
mineralised ore feed from is undoubtedly a plus -enabling separate teams
to work with reduced hindrance allowing for more time to concentrate
on being precise -reducing dilution during mining & extraction processes.
( the fact that so much veining is continuous is a huge bonus)
That will be 5 separate mineralised ore areas if tails is included another
massive bonus when the inevitable mining hold ups -breakdowns etc.
inevitably occur from time to time.
So what we do know
The Tailings has 9.3g p/t recovered at reputably 90% recovery from the
hammer mill & is being independently verified-
regardless its a good number.
Important to comprehend
The gravity plant was recovering 2g p/t approx.-dismal but that's not the point
you can add this two grams per tonne recovered to the tailings grade
of 9.3 g p/t, as although dismal it was still recovered prior to gold going to tails.
So that's approx. 11.3 Grams per tonne -taking into account recent tails sampling
recovered 90 % -regardless its the same hammer mill process the newly revamped
gravity plant will be utilizing in liberating the gold.
So we are at an equivalent approx. 11.3 g p/t at 90% recovery at minimum-imo.
BUT !-This would be without dilution being further controlled !
What do you add as increased recovery from the implementation of
improved recovery from minimising dilution ?
Quote
As a result of our recent successes" new ore extraction methods have successfully been implemented in the development drives" and a new low-cost blasting method has successfully been implemented in the stopes
as OGX claims to have achieved ?
Clearly we don't know what to allow but it should be a plus over & above what
the cluster fcks running the show prior achieved !
So 11.3 g p/t-( 2 g p/t recovered pre revamped gravity plant & 9.3 g p/t
thus far in tailings.)
So 11.3 g p/t -plus ? improved method of mineralised ore extraction =?
Lets just say-MORE
What about this little gem of a comment-
Importantly this stockpile was not from
material processed from the higher grade and finer gold Mestre zone that we suspect has
gone into the tailings also.
Hence-A higher grade possibility in tails than the 9.3 g p/t reported from processing
of 5 x one tonne samples.
So with out any improvements to mining method & control of dilution or
allowance of an improvement in average tailing grade due to-Quote
material processed from the higher grade and finer gold Mestre zone that we suspect has
gone into the tailings also.
We are at 11.3 g per tonne in recovered gold
Seriously at 11.3 g p/t -What's not to like ITS ABOVE 1/3 OF AN OZ PER TONNE
with out factoring in other very likely recovery improvements stated in Asx Ann
by OGX & mentioned above.
Will see what eventuates & unless we are being told porky pies & I seriously doubt it
we only await conformations.
In OGX's opinions from information compiled from recent Asx Ann
gltah
salt