Hedley BC they relocated the tailings onto a large mat which slopped to one corner then sprayed a cyanide leach over the top of the pile.
As the cyanide peculated through the medium gold was picked up, the pregnant liquor collected in the ponds from there it was passed through a large filter filled with zinc chips.
Zinc cements the gold from the liquor as slime's the barren leach returned to one of the ponds. A sample taken for titration , from the results the operator knew how much cyanide was needed.
Titration
Photo labs, X'ray labs and dental offices use a similar heavy metals trap to recover the silver.
Instead of zinc the filter is filled with steel wool.
When Pat and I had our scrap yard, one morning while heading to the jobber for a parts when I got to the stop sign would have had to turn right to get to town.
As I was looking to ,my left to see if the road was free of traffic spotted a yard sale sign.
Made the left, interesting yard sale, the heirs were selling off their fathers goods from a business he had once owned.
Out of the blue the fellow asked me if I picked up scrap, after telling him that I did. He took me inside the garage.
Inside was a one hour photo lab which consisted of many large pieces along with many new and used Radio Shack inventory.
Truck loads o camera's and 35 mm projectors tubes, new bulbs and belts. Advertising and manuals for a lot of the old 35 mm camera's
People brought their camera's in for repairs but once they received an estimate had abandoned the camera.
Every disassembled camera stored neatly in a box, we were clueless. Listing them on auction we simply labeled the first box A1 going forward. Posted images and let the bidding begin.
At the time I had a crane truck large enough to lift a car or truck onto the deck then stack another on top of the first.
When I came with the truck to pick up the photo lab, the last thing I had picked up was the silver recovery canister and it was heavy.
I told the guy that it contained silver and that he should send it into a refinery. Told me to keep it, we sent it to the refinery and received a nice check in the mail.
On another occasion a buddy purchased a building on a tax sale, the building had been used as a dental office and it had all the equipment, chairs, drill stations, box's of preformed crowns, compressor in the basement along with many old heavy metal filter traps sitting on a self.
The heavy metal traps capture the mercury along with silver, gold and any platinum sister that maybe present. Blood and bone chips these things stink bad enough to gag a maggot.
I built a retort to drive off the mercury as a vapor which condenses back into a liquid before leaving the retort.
What is left is a grey looking powder, the values.
If your going to play with tailings have an assay done, you need to know if any harmful elements are present.
