Reclaimed Gold Pins from Cellphones

Quote: Originally posted by Twospoons

You do realise that those pins are merely plated with gold, not solid - with said plating likely being a mere 20 um thick or thereabouts. So your 70g of pins probably contains under 1/10 of a gram of gold. Which is about four bucks worth. You'd do better to put them up on ebay, and let someone else do all the hard work! [Edited on 18-5-2016 by Twospoons]

ok, this is what about 1kg of carefully trimmed up computer boards looks like before and after.
the gold on the right is thin foil and the beaker is about 8cm across. the deep blue/green grunge on the left is all the other metals in there. the gold is minimal at best. I do it for fun not profit.

this is only the first step in getting clean gold, btw. it needs to be dissolved in a nasty acid combination and the crystallised again using another chemical.



the reason gold is used is to improve the quality of connections inside the device. so the gold is only useful if it is the outer coating. so if you have cut a pin open and it looks gold inside and silver outside, you can pretty much bet that it is in fact a copper pin with lead/tin coating. total value: about 0$, less the expense of the chemicals used to process it. there is no point in making gold pins and then plating them.

[Edited on 18-5-2016 by diddi]

Quote: Originally posted by shootinginthedark

His explanation was that there was solder on top and the bulk of the interior was gold. Does that jive with reality at all? He assumed of the 2.5ish oz i'd get a little over an oz of gold. How the hell did he arrive at this

He is incorrect. All electronics that use gold use an incredibly thin plating. Its only purpose is corrosion resistance, so a thin plating does the job at minimum cost to the manufacturer. There are many ways to go about recovering the gold, nearly all of which involve 'scary acids'. The videos j_sum1 linked are a really novel approach that was pioneered on this forum, and is quite a lot less hazardous.

Moral of the story, though, is that electronics scrap won't net you hardly any gold at all and isn't profitable processing unless you have literally tons of free scrap and cheap chemicals. I plan on doing it at some point because it's interesting to me and will be a fun exercise. If it's something that you think you'd have fun doing, go for it! Maybe this will be your introduction into the exciting world of chemistry

Quote: Originally posted by MrHomeScientist

Quote: Originally posted by shootinginthedark   His explanation was that there was solder on top and the bulk of the interior was gold. Does that jive with reality at all? He assumed of the 2.5ish oz i'd get a little over an oz of gold. How the hell did he arrive at this He is incorrect. All electronics that use gold use an incredibly thin plating. Its only purpose is corrosion resistance, so a thin plating does the job at minimum cost to the manufacturer. There are many ways to go about recovering the gold, nearly all of which involve 'scary acids'. The videos j_sum1 linked are a really novel approach that was pioneered on this forum, and is quite a lot less hazardous. Moral of the story, though, is that electronics scrap won't net you hardly any gold at all and isn't profitable processing unless you have literally tons of free scrap and cheap chemicals. I plan on doing it at some point because it's interesting to me and will be a fun exercise. If it's something that you think you'd have fun doing, go for it! Maybe this will be your introduction into the exciting world of chemistry

Quote: Originally posted by aithecomputerguy

Actually, the purpose isn't just corrosion resistance. It also has one of the lowest capacitance of any metal, so it cuts down on noise.