Page 1 of 1

recovery of gold from electronics

Posted: Sun Apr 25, 2004 7:01 pm
by Chuck Barker
i realize that it is not profitable to do this at home...but...i would like to learn how. making the acids seems to be the hardest part as there several ways, but not enough info. on using home made equipment. has anyone tried or have any information on this? nitric acid and aqua regia can be made several ways, which is the safest? the other acid can be gotten in different forms.
thank you for your time and effort...

Re: recovery of gold from electronics

Posted: Sun Apr 25, 2004 10:27 pm
by Chris Smith
Acids are not the way,.... Heat and mercury are the catalysts. <p>Mercury however is extremely toxic, and must be controlled 100% in, and out of the process.<p>Its the same Alchemy of the dentist.

Re: recovery of gold from electronics

Posted: Mon Apr 26, 2004 6:14 am
by L. Daniel Rosa
Amalgamation and distillation? Sounds better than a cyanide bath.

Re: recovery of gold from electronics

Posted: Mon Apr 26, 2004 9:48 am
by jwax
Your biggest problem is how to get to the gold-if it's molded in plastic it's not available for any of your etchants. Exposed gold on connectors, pcb's, etc can be safely etched (disolved into, then reclaimed) by what is called "KI&I". It is a mixture of Potassium Iodide and Iodine. Reasonable safe,and available premixed from semiconductor chemical supply houses as well as chemical suppliers. A gallon of KI&I will hold about 2 ounces of gold in it.

Re: recovery of gold from electronics

Posted: Mon Apr 26, 2004 1:28 pm
by haklesup
Cyanide is less harmful to the enviornment than elemental Mercury in the long run since it will break down. <p>Etching using KI&I is generally safe and effective (selective) and should be easy to get.
4.3g KI + 1.3g I + 100g H2O<p>Aqua regia (hydrochloric and nitric acids in various ratios) will dissolve other metals as well and thus is not very selective. It will also etch just about any metal except Ti and Ta.<p>Another etch in my book is 1 part 10% potassium perra cyanide (aqueous) + 1 part 10% Amonium per Sulphate. Fairly selective but quite toxic.<p>In any case, once the gold is in solution, you can use electroplating to return it to a pure form.

Re: recovery of gold from electronics

Posted: Mon Apr 26, 2004 2:45 pm
by Chuck Barker
thanks for all the info., i'll check around and see what i can locate for the different methods. my main problem is, if it can't be obtained at ace hardware or radio shack i'm s.o.l. i have several books, new and old that say "buy acids and chemicals localy"...not anymore. each process seem to require one or two things that aren't availably localy...i'll try to take this info. and see what i can do...thanks again for the help