High pH leach question

jsargent · Nov 9, 2008

I'm going to run some bench tests on the placer material I'm working with using a "reverse" leach for gold at high pH. Non-cyanide of course. Any favorite protocols for thiosulfate, chlorine, T-6 etc. would be appreciated.

The material is finely ground placer sand, iron/black sand at 2%-5%
5 gallon buckets w/ 10 pounds of material in stirred or air agitated slurry
Temp = 65F.

Gracias!

Anonymous · Nov 9, 2008

Reverse Leach? does that mean your adding gold to the sand?

Platdigger · Nov 9, 2008

No, it means, instead of running on the acidic side, you are on the alkaline side while leaching.
I think the term may have been coined by the guy at goldmineworld.
Randy

Pawnbroker Bob · Nov 9, 2008

SSN

Will work at 65F but if you can warm it to 85+ takes a lot less time. Ph around 1 safe and no toxic fumes unless you have Mn will vent a little chlorine gas and magnetite will gas off some nitrous oxide but only for a few minutes then quit.

PB

jsargent · Nov 9, 2008

Platdigger said:
No, it means, instead of running on the acidic side, you are on the alkaline side while leaching.
I think the term may have been coined by the guy at goldmineworld.
Randy

Yeah I ran across the term there... it's just a basic leach but if I said "basic" the question would have been if I meant "fundamental" instead of "alkaline". So, I said "reverse" meaning the reverse of the standard acidic not putting the gold back in... :roll:

jsargent · Nov 9, 2008

Pawnbroker Bob said:
SSN

Will work at 65F but if you can warm it to 85+ takes a lot less time. Ph around 1 safe and no toxic fumes unless you have Mn will vent a little chlorine gas and magnetite will gas off some nitrous oxide but only for a few minutes then quit.

PB

SSN? (Saturated Salt Nitric?) No... I want to go alkaline on this one. Have to go at ambient temp too but I'm sure higher temp would accelerate things.