snip--
I used it when I was closing the doors on my refining business, to clean up accumulated plated pins (wire wrap components). I processed something like
150 pounds of clean pins and strips. As you alluded, it works fairly well, particularly when there's a nickel barrier. Given an opportunity, I'd never use it if I had the option to strip with sulfuric acid, though. That process is fast and clean, and certainly less hazardous than cyanide, although hardly totally safe. You tend to run blind with the cyanide stripper.The thing you need to watch is--- if it starts attacking copper, if it's precipitating gold in the process. You'd never now, it doesn't look like gold, it's just dark brown or black crud. It gets tossed, and you wonder what happened to your gold.
If you don't know, our own government was (is?) involved in recovering gold from plated items back in the '75, in New Mexico. They were using the sulfuric process at the time. I was flown there by a client, who made arrangements for me to inspect their stripping cell in order to duplicate it for him. The trip was a grand success, and I built two stripping cells. This was in the transition period, where I was still running my commercial shop, but refining on the side for grins. I was shocked to hear that the government had recovered what I recall was something like 35,000 ounces of gold the previous year. Old microwave stuff was very heavily plated. Some of it yields as high as 3% gold, which boggles the mind by today's standards. I used to purchase wire wrap connectors and modify them for a defense contract customer. The pins were plated with less than .0001" gold, very unlike the stuff in question.
The screwing I got when I sold my platinum two years ago is hard to believe. I recalled the material from one source when they tried to convince me that it was down around 70%------the second refiner started off much better, but still got to me over the long haul. They have you over a barrel with the platinum group----there's a huge demand, but a very closed market. If you're not on the inside, you can figure you're going to get screwed. I wasn't, and I was. :-(
I have other war stories-equally as bad. Large refiners have no interest in dealing with the common man, and make him sorry if he insists.
Harold