Lead concerns and general newbie questions

[bob800]

Hi, I'm new to gold refining and found this forum extremely helpful for getting started in this hobby. I decided to use the acid-peroxide method for collecting the gold flakes from gold-plated fingers. However, I also found a bunch of gold-plated pins on some chips, and realized that I could also scavenge these for more yield. However, I noticed that the bottom of these pins has some solder on them (containing lead I'm sure), and since lead is above hydrogen in the electromotive series, I would be under the impression that the lead would dissolve in the AP mix (especially with the peroxide): Pb + 2HCl ---> PbCl2 + 2H.

Since lead salts can be quite toxic, would this pose any significant health risk? Since wikipedia lists lists lead(II) chloride as only slightly soluble in dilute HCl, I would assume that the amount of lead in my leftover solution would not pose an environmental hazard (after filtering, of course). Am I correct in thinking this?

Also, I was thinking of disposing of the leftover CuCl2 by adding excess iron metal to precipitate copper metal in a solution of ferrous chloride (since iron is more active than copper): CuCl2 + Fe ---> FeCl2 + Cu. Then, I could then add washing soda to precipitate iron carbonate, which I could then dispose safely in the garbage: FeCl2 + Na2CO3 ---> FeCO3 + 2NaCl. Do you think this disposal method would work?

Finally, are there any toxic materials in the circuit boards (which the fingers are attached to) that I could get significant exposure to when dissolving the fingers in the AP mix? I'm not going to chuck the whole motherboard in the AP mix, of course; I'm only concerned about the composition of the circuit board. Wikipedia lists mostly epoxy resin, Teflon, phenolic cotton paper, woven glass fibers, and other (mostly) non-toxic materials, but I just want to make sure there's no arsenic/mercury/cadmium in these PCBs (or in such small quantities as to pose no significant health hazards).

Any help would be greatly appreciated! Thanks!

 

[nickvc]

Welcome to the forum and I like your approach over the concern of disposal of your waste.
If you go back to the board index you will find the safety section, start there and also download a copy of C.M.Hoke and the forum handbooks available from several members signature lines,Palladium is one of them and read and study those and most of your questions will be answered. If you have further questions use the search function and a visit to lazersteves site is also well worth while.
Everything to do with refining precious metals has dangers and hazards but our major concern on the forum is the safety of members,their family,neighbours and the environment so read away and if you get stuck post further questions.
As to your worries over various dangerous elements and compounds by reading you will become aware of how to minimise the risks and of how to handle and dispose of them safely.
This can be a fun hobby and you can make some money and if you wish to continue you have found the only truly reliable resource on the subject.

 

[ryan6342]

hello im a total noob. have a question pertaining to safety. what other metals can be found in the gold plated computer pins. i know some are solid but some are not. the plated ones would be what other metal or metals?

 

[Claudie]

:shock: Some are solid Gold??

Just kidding. There are no solid Gold pins in electronics. Gold is used as a plating to stop corrosion. Most pins will be Copper in the center with a Nickel coating, and then a very thin layer of Gold over that. The Nickel is present to prevent the Gold from migrating into the Copper. The Copper is used because of it's constructiveness, and the Gold is to stop corrosion. Hope this helps. :|

 

[ryan6342]

thanks that helps a lot, the leftovers were green pins with silvery look to them, i was like ? copper inside something inside gold? lol on eating one, i think i may have swallowed a piece of one at some point but just more or less for future reference i tried to usse a magnet to collect some of them and they were not magnetic. thanks