Americas Gold and Silver Corporation T.USA

Throw Away Line

[jdbutts]

Noticed reference to discovery of "naturally occuring carbonaceous material" in Q'ly Report and it got my spidey senses tingling.  Saw this gem in an abstract "The naturally occurring carbonaceous material (CM) in gold bearing ores often exhibits strongpreg-robbing properties. It can adversely affect the process of gold recovery during the cyanidation due to its ability to adsorb, or preg-rob gold from the cyanide leach solution".

[cosmicac]

Do we have a chemist who can translate???  Where does the gold wind up.... and why can't it be further isolated and recovered???

[RocksandStuff]

The gold is taken into solution by cyanide, but then is pulled out of solution by carbon in the rock. Essentially the gold stays in the heap leach pad attatched to carbon and can't be stripped away.

[cosmicac]

maybe another step... another step might be too expensive.....  Carbon very reactive gold not so... why can't something eat the carbon's ability to suck up the gold ... before the rock goes to the leach pad or once it is sitting there....I'm not a chemist (dropped ChemE major after 1 semester of everything having 3 names... } Do we know how much carbon is present???? 

[RocksandStuff]

You are correct you can do a carbon in leach circuit in which the gold attatches to your carbon rather than the preg-robbing carbon. The problem is the capital costs to build a CIL plant and processing costs would be higher. This would likely make the deposit not economic if it needed a CIL plant.

[cosmicac]

Thank you  RocksandStuff A few more questions if you don't mind????  From the data we have we know gold is coming out of the leach.... It is obvious that the peg-robbing carbon isn't eating all the gold....  First question to management then should be How much??? And how does Run of Mine  affect the process.    We also know that the 1st Q was

[RocksandStuff]

Yeah based on the quarterly production vs expected it looks like slightly more than 80% of the gold was preg robbed. Once you put preg robbing material on a leach pad the entire pad is no longer usable. Unless you just managed to put the carbonaceous material on a small portion of the pad and not over an entire level. They'll probably have to start a new leach pad or isolate the carbonaceous

[Thales42]

There's a chance the mine will never be economic now though, depending on how widespread the carbonaceous material is through the deposit.  I think it is more than a chance.  In addition to the ongoing operating diffculties, RC is a low-grade project and grade is the most important factor.  USAS mortgaged its future on RC and this blunder is unforgivable.

[BillyBats20]

Who makes a 68 million dollar blunder and keeps his job?  38 million to buy the the RC dumpster and 30 million for the mine. The CEO states very simple heap leach, brownfield mine site, recoveries are quite simple? So its either a complete scam to sucker investors or this guy is completely clueless. Hard to believe Sprott and Lassonde are invested in this with this Donkey at the helm. Board

[Thales42]

There is more to RC gamble.  USAS shareholders were hit with series of dilution while Sprott took hold of 40% ownership of Galena.  If RC is declared a writeoff and with Galena now only 60% owned, what is left of USAS is in much worse shape than before taking over RC from Pershing.  Management and the board must be sh---g in their pants knowing that they can be held liable

[cosmicac]

Before you start writing off RC... note that only 1/2 of the expected stack was in place for more than the first 1/3 of the quaerter and the stack wasn't full until some time later in the quarter.  By the end of the quarter only a small part of the stack had material in place for the required length of time.   Just a thought....