A lot of you have been around long enough to realize that one of the most important things would to be able to strip gold off without dissolving the base metal. That way, it would be faster, cheaper, and would produce less waste. You would not only have gold to sell, you also would have copper. If you ever come up with a new, cheap, safe method for doing this, don't tell anybody and quickly get a patent on it.
About the only things that have been found to do this are cyanide/oxidizer, iodine/iodide, and bromine/bromide. It's also maybe possible to use hypo (sodium thiosulfate). As Sue suggested, somebody should experiment with hypo. I used cyanide every day for about 20 years. Sometimes, I worked around 5000 gallon tanks. It is cheap, efficient, safe, fast and, most important of all, it can be completely destroyed. It's formula is CN and it can be broken down to CO2 and N2.
The following is a secret, never told, so don't tell anybody :lol: . I'll probably never do anything with it.
One day, in L.A., I got the idea of using abrasives to remove the gold. I put some pins in a rock tumbler along with some silicon carbide powder. All the pins got was dirty. I did no more work on this. I think it will work with the right abrasive. The problem is in separating the gold from the abrasive. Probably something like a separating table or a spiral wheel.
The Wheelabrader. I think that's what they call them. This is a vertically rotating, cage like, wheel with small holes in it to prevent the parts from falling out and to let the sand fall through. It is designed for small parts. Inside of the wheel is a sandblasting nozzle. The wheel is inside of a sandblasting booth. The parts are put into the wheel, the nozzle is turned on, and the wheel is rotated. The metal wheel is coated with a rubbery plastic to prevent the sand from eroding the wheel. Eventually, every part is completely sandblasted. It gets in all the holes and the cracks. There's really not much to them and they could be made.
I spent about 4 hours, one day, doing experiments in a company that sold Wheelabraders. I had lots of bags of different types of parts, including rhodium plated jewelry. I tried several abrasives that worked so-so. However, the problem of getting the gold out was always on my mind.
I finally tried some glass shot and steel shot peening media. This stuff worked great and fast on everything. Instead of abrading the gold off, the shot peens it off. During peening, the plating layers are peened thinner. This stretches the gold sideways and it just pops off (along with the nickel).
Some of the steel shot Wheelabraders have built in magnetic separators to clean the shot from the garbage. Gold flake collection should be easy with one of those.
EDIT: Since this post, I found out that there is a piece of equipment called a Wheelabrader but it is much different than what I described. I don't know what the machine I used is called.
About the only things that have been found to do this are cyanide/oxidizer, iodine/iodide, and bromine/bromide. It's also maybe possible to use hypo (sodium thiosulfate). As Sue suggested, somebody should experiment with hypo. I used cyanide every day for about 20 years. Sometimes, I worked around 5000 gallon tanks. It is cheap, efficient, safe, fast and, most important of all, it can be completely destroyed. It's formula is CN and it can be broken down to CO2 and N2.
The following is a secret, never told, so don't tell anybody :lol: . I'll probably never do anything with it.
One day, in L.A., I got the idea of using abrasives to remove the gold. I put some pins in a rock tumbler along with some silicon carbide powder. All the pins got was dirty. I did no more work on this. I think it will work with the right abrasive. The problem is in separating the gold from the abrasive. Probably something like a separating table or a spiral wheel.
The Wheelabrader. I think that's what they call them. This is a vertically rotating, cage like, wheel with small holes in it to prevent the parts from falling out and to let the sand fall through. It is designed for small parts. Inside of the wheel is a sandblasting nozzle. The wheel is inside of a sandblasting booth. The parts are put into the wheel, the nozzle is turned on, and the wheel is rotated. The metal wheel is coated with a rubbery plastic to prevent the sand from eroding the wheel. Eventually, every part is completely sandblasted. It gets in all the holes and the cracks. There's really not much to them and they could be made.
I spent about 4 hours, one day, doing experiments in a company that sold Wheelabraders. I had lots of bags of different types of parts, including rhodium plated jewelry. I tried several abrasives that worked so-so. However, the problem of getting the gold out was always on my mind.
I finally tried some glass shot and steel shot peening media. This stuff worked great and fast on everything. Instead of abrading the gold off, the shot peens it off. During peening, the plating layers are peened thinner. This stretches the gold sideways and it just pops off (along with the nickel).
Some of the steel shot Wheelabraders have built in magnetic separators to clean the shot from the garbage. Gold flake collection should be easy with one of those.
EDIT: Since this post, I found out that there is a piece of equipment called a Wheelabrader but it is much different than what I described. I don't know what the machine I used is called.
