Ann: Operational Update from the Old Pirate Gold Mine, page-78

Hi Juk, I have gone back and reviewed
report 23d jan (dec quarter)
17.8 g p/t was calculated head grade ( feed ) not recovered grade post processing,
this was quiet obviously always wrong ?
imo

Report stated 3,094oz sold & 130oz delivered to mint-total 3,224oz
Processed tonnes 9,844t.
Gold thus far was 3,224 oz x 31.1 gr =100,266 grams,
equates to 10.18 g p/t recovered.
They then calculated a theoretical ( turned out to be wrong),
an allowance of 1,000 oz in circuit, add 31,100gr.
Processed tonnes 9,844t.
Would then be 4,224 oz x 31.1gr = 131,366 gr.
Equates to 13.34g p/t recovered @ 86% recovery imply head grade was 15.5g p/t.

report April (march quarter)
mill clean out 224 oz
Total processed gold 3,230 oz
Total oz gold produced trial minning 3,454oz x 31.1grams =107,419 grams.
If tonnage was 9,844t it would have determined a gold recovered grade of 10.91 g p/t.

Quoted passage from report

After completion of the trial mining and processing programme the detailed weights and assays were collected and reviewed by an expert independent metallurgical consultant - Mr Roland Nice of RW Nice & Associates Pty Ltd.
Following revisions to the original weights fed to the plant by reconciling survey data and site estimates using loader bucket counts, it was concluded that the trial operation treated 8,122 dry tonnes of material.
The lower estimate of tonnes treated than previously reported is mainly due to previous over-estimation of the dry bulk density (tonnes per cubic metre) of the surveyed stockpiles from near-surface material.
The back-calculated head grade is therefore 15.4g/t gold, based on the sum of the Perth Mint outturn plus the gold contained in the tailings calculated using daily assays and tonnes fed. (No allowance is made for other gold that may remain in circuit)
Using the same data the calculated recovery is 86%. Mr Nice stated that the trial plant performance was less than ideal for a number of reasons.
Remembering these guy's are primarily geologists & management that got some things wrong not,specialist mining contractors,
its understandable in my view.

Therefore mill clean out 224 oz (not miscalculated 1,000oz in Dec quarterly report ?)​

Total oz gold produced trial minning 3,454oz x 31.1grams =107,419 grams
Total tonnes 8,122
equates to recovered (post processing )
gold grade of 13.22 g p/t @ 86% recovery.

So take away if head grade 15.4g p/t, same as trial mining and coyote recovery is say 98.5% (and not only 86% as per trial mining), then the equivalent recovery from coyote if dilution could be controlled in the same manner as trial mining,
would equate to 15.17g p/t of gold recovery.
( indication only as ore grade will obviously vary )
salt