golden_egg said:
I found some deals (or not) on eBay that say Gold Filled and some that say RGP (Rolled Gold Plate). I found out the hard way to avoid RGP. however even the ones that say Gold Filled by itself are super magnetic. I'm sure I can recover something from this gold plated crap but not as much as if it where truly gold filled. What is the possible yield Equation for gold plated stuff? I'm some what familiar with reverse electro plating. so would that be the way to go? Please advise.
Only deals on ebay are raw ones. ...sorry that you found out as I did.
Well. Its super simple. And posted here before I'm sure.
Approx yield = weight × filled amount × karat
Lets say the weight is 100 grams of 1/10 12k gold filled ...
The gold filled amount is. 1/10
1/10 (0.1 or 10%) of 100 is 10
Karat is 12k (50% gold)
Ergo, on the best of days 5g BUT
(This is a big but)
The gold wears, a LOT in some cases. So you could be getting a gram in some instances.. another cheek to that but is, legally manufacturers are allowed a bit of wiggle room on that "12k" mark. Mostly .5k but up to 1k (hoke spoke on it, briefly)
A small sidenote, if its just marked "gold filled" or g.f. it is 1/20
...rolled gold (if i recall correctly is 1/25 or 1/30)
I pay between 20-50 cents a gram depending on what it is. Eyeglasses, pocket watches I do higher, because they are better. Wrist watches are so annoying, and so labor intensive, I offer the low end of that. (Some glasses have gold bridges, rare but..some)
That price gives me wiggle room for wear, chemical cost, waste treatment, and the little bit I make for my time.
As far as your magnetic g.f. problem. In the past I have tackled it a few different ways. Cheapest, safest way is put it in AP with a bubbler and forget it for a 6 months to a year, then finish recovery and on to refining.
Way two is how I went about some TO92 transistors, which was dissolve whatever I could in hot dilute sulfuric (bonus points for making copperas from that "waste")
Way three, (which is not to be trifled with) is dissolve it in nitric, once the iron starts accumulating on the bottom, I would add the smallest amount of sulfuric (has to be cold! Else you may have acid instantly boil, ferociously, and get on your face and that would ruin more than your weekend..) the sulfuric would keep the iron in solution and the nitric would keep working at the constituent elements of the kovar
Ebay is evil to rookie refiners. Unless you are selling... but, then they take like 13-20% of the total for every sale made..so, they get you coming and going.. evil.
Anyways, I hope this helped a bit
