Best process?

[JWalker]

I was surfing around and I found these on ebay (link below) and I was curious if anyone the Forum has had any experience/luck separating the PM from the base metals on these and if so, what method you chose to use. For those that dont use the link it is a melted gold button, BUT they melted the scrap pins (kovar, copper, etc) in with the gold,... i'm assuming tin soldier and all.

http://www.ebay.com/itm/40-9g-Gold-...713?pt=LH_DefaultDomain_0&hash=item3f2a06ddc9

 

[chlaurite]

Search the forum for "pin bullion" or "Doré bar" - Although the latter name (if you recognize it) makes them sound much, much better than their reality

Quick and dirty summary - These completely suck for recovering PMs. Although you can file/grind them down and run them in AP to recover the gold more-or-less as fast as you could do the same for unmelted pins (ie, a month or three), the gold you recover that way will take the form of a difficult-to-handle black powder, rather than visible-sized flakes.

Most importantly, a "real" Doré bar (as produced by a mining company for convenience in shipping to a proper refinery) actually has somewhere on the order of 50-75% gold content (with silver making up much of the balance). These lumps of melted pins, however, will have a similar yield as you would get from pins in general (and you can bet the farm the seller didn't use all high-grade CPU pins) - So expect somewhere on the order of 0.25 to 0.5%, or, conservatively, a hair over one gram of gold per POUND of those. The link you give goes to a lump of metal somewhat less than a tenth of a pound, for reference.

If someone gave you that lump, you could probably recover $2-3 in gold from it. Doing so would probably cost you more than that just in chemicals, even ignoring your time spent on the task.

 

[JWalker]

I knew it was bad, just not that bad. :shock: I started to think of the yield from 40g of medium CPU pins and realized that the effort or grind the whole thing down and then try to recover with HCL/CL or AR would be an exorcise in futility. Thanks for the complete answer!

P.S.
My favorite part was teh description stating that the lump is worth HUNDREDS! over and over. If it's worth HUNDREDS why not sell it for at least um.. One Hundred? Fifty even....?

 

[bswartzwelder]

Those bars and buttons made from computer pins have been on eBay for quite some time. They are a super great deal for the seller, but no one else. Another scam involves selling of "high Grade gold ore" from the Jinfeng mine in China. Out of curiosity, (and because it was so cheap) I purchased several pounds of this "ore", crushed it into a very fine powder, and treated it to a nice long soak in poorman's AR. Then I tested the solution with stannous chloride. I have never seen such a strong NEGATIVE. I know the stannous was working because I bought a bottle of known strength Auric Chloride solution from a chemical supply house in the US to use as a standard solution against which I test my stannous chloride. Once crushed, you cannot return the ore for a refund, and if you leave a positive feedback for the seller before you actually process the ore, you have no recourse.

Several other forum members have had negative dealings where some of these eBay scams have come to light. While there are some good deals on eBay, very few of them involve precious metals. Hope this helps. As long as there are people on this forum who will help expose these fraudulent schemes, someone else will take the hit. Caveat Emptor. - Let the buyer beware.

 

[Geo]

you would be be well advised to leave "gold drops" alone. pins are easily recognized and valued by people who work with them. one ploy to disguise them is to melt them into a blob. if someone thats honest wanted to sell their pins, they will take pictures of their pins and sell them by taking their chances on auction. a dishonest person may melt ANY type of brass metal and call it "melted pins" or "gold drop" just to take advantage over the gullible.