Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Recovering gold from electronics, page 3
Q. Hi,
I am someone who had just bought some scrap metals. I am doing this for an experience and knowledge. I have learnt how to use aqua-regia or electrolysis to get gold. I am not sure about the purity but I can see that it's gold. But now I want to extract other metals in the scraps as well. How do I get nickel and copper from it? I have dissolved the scraps in the aqua-regia and got gold. Now I am still left with the remaining mixture. How do I recover nickel and copper? Can someone please advice me on the procedures I can take to recover them? Or some info? Please, my knowledge in this is shallow.
Thank you.
Ung ShunjinHobbyist - Johor, JB, Malaysia
2004
A. The decision on refining gold by a hobbyist is a hotly debated item at best. The first and foremost thing to be considered is the fact that no matter how careful you are, there will always be a good chance that your hobby will kill or cripple you or someone you love.
There is no such thing as a "safe" method that can be "profitably" used by the average hobbyist. I know this because I have been recycling & recovering both as a hobby and for 2 employers for over 10 years. If you truly want to experiment with recovery then you need to invest in a detailed manual and study it intensely.
Several of the larger chemical supply companies offer safety courses ranging from free to $25. TAKE ONE! Then if you are absolutely sure you still want to try home recovery start small & start with safety foremost in your mind. Don't waste your time expecting to get rich, it ain't gonna happen.
Jim Huffman- Winchester, Tennessee, USA
2004
Q. I have a fairly large amount of gold in solution. I've evaporated off the nitric and now it's in hydrochloric acid. Can anyone tell me what will precipitate the gold? Also, will nitric remaining in the solution influence the precipitation and if so, how can I test for it.
Tim RobertsHobbyist - Mesa, Arizona, USA
2004
A. Tim, When you have the solution in HCl form and works if it has some HNO3 left in it (perhaps better) you can dilute it with water, about 2000 Ml. and after bringing to a boil add "Potato White" which is sodium metabisulfite while stirring (use three times as much "PW" as gold as you anticipate) (You can buy it at a chemical supply house as a food grade very cheaply) . Then add more "PW" and see if you get a cloud, if you do you are precipitating more gold. Try a small amount and be sure there is a small Amount of HNO3 still in the solution and that it is dilute enough to be able to see through it with a light behind it.
If there is no more clouding let it cool and settle then filter through a tight filter. If you have any white precipitate you have added too much "PW" not that it will hurt but give you an indication for the next trial. The good stuff will look like coffee grounds sort of. Place the solids in a new beaker [beakers on eBay or Amazon [affil links] and boil with water to clean the white material out. or
I would just melt the entire batch in a crucible and you will have pretty good gold. about 95% or better.
I add pure lead and 4 parts silver then use a cupel to separate the gold from anything else and get about 99%
Good luck
Adrian Meador- Muleshoe, Texas
2004
! Tim, In the last note I neglected to add that you need to part the cupelled button with 50% nitric acid to dissolve the silver and leave the gold in a very pure state.
Adrian
Adrian Meador- Muleshoe, Texas USA
2004
Q. I WOULD LIKE TO KNOW MORE OR LESS HOW MUCH GOLD ONE CAN REFINE OUT OF A 1000 POUNDS OF COMPUTER MOTHERBOARDS.(RANGING FROM 486 TO P1)?
Dirk WaltersHOBBYIST - Vanderbijlpark, GAUTENG, SOUTH AFRICA
2004
Q. I have about 10 lbs of scrap electronic pins and fingers and would also like to refine scrap jewelry. Would it be worth my while to spend $600.00 on refining equipment to under take this task? The equipment I am referring to is the simplicity sold by Shor.
Carl Naglhobbyist - Bayville, New Jersey, USA
2004
A. As simple as I can state it. One computer contains approx. $1.20 in precious metals and it cost approx. .80 cents to retrieve it (and that is, if you do the recovery perfectly), so you profit .34 to .40 cents . Notice I said one computer... you can strip it down to the boards, chips, and pins and still going to profit 34 to 40 cents each. hope this helped.
Frankie Burk- Pulaski, Tennessee
2004
Q. I have a few pounds of gold plated electrical components. Most are very small pieces. I just read that you should never use AR for platings. My question is, How do I recover the gold? Every refinery that I've asked is not interested in plated gold.
Gregg Bremersnon-profit religious - Lincoln, Nebraska, USA
2004
Q. I am interested in removing the gold from circuit boards and was wondering if you could remove it strictly by using electricity.
Thank you,
Dan Pridgenhobbyist - Mobile, Alabama
2004
Q. I have about 100 lbs. of low-grade gold plated eyeglass frames. My goal is to recover the gold myself. I have done some experimenting and it appears that melting them and constructing some type of Mobius or Thum cell would be the best approach. I am open to suggestions on all parts of this project
Mike RotalskyHobbyist - Franklin, North Carolina
2004
Q. I am involved in a research project to recover gold from electronic scrap. The sample that I am working with have a high concentration of copper compared to gold. Hence, this makes the recovery process of gold difficult. Is there any method or sorbents that can separate gold from copper? The concentration of the copper is about 10 times more than gold in my sample.
Ryan TongStudent - Singapore
2004
Q. Need to know how to remove gold from circuit boards. Step by step in laymen's terms. I'm not super smart so please explain in steps. I would appreciate any advice. I have access to lots of old computers and would like to recycle as much as possible.
Thanks,
John minncomputer repair - Edmonton, Kentucky, USA
2004
Q. Hi, I'm a business man engaged in buying any kind of scrap such as an electronic scrap. With this, I have collected plenty of IC's (integrated circuit) from these electronic scrap. I have at least 30 kilos of LQFP and QFP package of IC's with different number of pins from 44 pins to 144 pins. I would like to know how much ounce of gold I can get from these IC's.
I would like to recover the gold from these IC. With this, I have performed an experiment using sulfuric acid to melt the molding compound of the IC's and then sort gold wires from the melted molding compound and copper pins. This is a long and expensive process so I stop the experiment. Instead, I use the aqua regia to recover the gold.
By heating the IC's with aqua regia at 300 °C the IC's (molding compound, copper pins and gold wire) were dissolved leaving the molding compound at the bottom. Then I filtered the solution and neutralize the nitric acid using a urea. After doing all this I'm not successful in precipitating the gold, using sodium sulfite. What I get was a black powder and white powder at the bottom. I burn to melt these powders and obtain a black colored metal not gold.
If somebody from you guys out there who have experience in recovering the gold from IC's can you please share to me some tips or more accurate, economical and safer process that what I'm doing. I already tried three times in perfecting the aqua regia process to recover the gold from my IC by not Successful. Desperate for your help.
Alex MasterScrap Buyer - Makati, Metro Manila, Philippines
2005
Q. I have used aqua regia to dissolve gold and silver from e-junk. Can the electroplating system be used to bring the dissolved gold back to gold metal? If it can be done what material should the anode and cathode be ? What acid should be used? Also, how and what is used to bring back the dissolved silver?
BILL Luxmorehobbyist - PEACHLAND , BC, CANADA
2005
|
It seems like we all have something in common. Those who have the answers won't share them. I have had some success in extracting the gold off of connectors and "broken fingers" using "pcb etchant solution"from radio shack cat#276-1535. It takes longer than nitric,but is a lot safer. It works best when hot, not boiling, straight from the bottle. When dissolved, by using electrolysis on the copper the gold is easier to get too. Do not use this on aluminum. on the ceramic ICs use hydrofluoric acid also know as glass etchant to dissolve the casing. But, when all ELSE FAILS I use Abington Metals in Philadelphia, PA USA as my refinery. Linda there is a great help; if you don't know what you have, send her a sample and she will tell you what it is and if is worth anything. I hope this helps someone. Hi Doug. Thanks for your answers, but it's not fair or realistic to characterize the readers as "those who have the answers won't share them". Informative postings have already been offered by Panjala Mukesh, Arnold Hoskins, Richard Alcorn, Peter Couture, Rhangy Smith, Adrian Meador, and others. Other readers suggested books which describe everything one might want to know, feeling that people should read up and acquire some chemistry & refining background before possibly endangering themself or wasting gold with inefficient procedures. People can give step-by-step instructions for baking a cake because readers are already familiar with eggs & flour and fruits & granulated sugar & bottles of vanilla, and whisks & glass bowls & teaspoons & kitchen ovens, etc. But they can't give a novice "step-by-step" internet forum instructions for performing an appendectomy because it involves terminology & complex procedures that people aren't familiar with, so "Step 1" grows to fill 100 pages. While recovering gold waste isn't as complicated as an appendectomy, it does involve terminology and procedures that laymen won't instantly understand -- that's why the book may be a couple of hundred pages rather than two paragraphs. Thanks again. Regards, |
Q. We just acquired a very large surplus of computers & need to know what parts have gold on them. We don't know what "chips", connectors, etc., we don't know one chip from another. Is there a diagram that shows what parts are salvageable? How do you refine it?
Debbie Smithamateur - Montana, USA
2005
Q. Have removed most of gold and other metals from 32 year old computer; now what do I do with it? Help me please: my husband was Vol. Fireman who was disabled in line of duty; this is something he started before totally disabled and we could use any financial help possible. He was sure when he did it it was a good thing; been sitting here about 7 yrs. If you have suggestions please.
Thank You,
- Cadiz, Kentucky, USA
2005
A. While there was more gold on typical electronics in 1973 than today, computers use a few millionths of an inch thickness of gold, the parts are not made of solid gold. I hate to have to be the one to tell you, but the value of the gold from even a 1973 computer may not buy much more than a Happy Meal. But take it to any jeweler or pawn shop who says they buy gold, and see what they say.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005
A. My experience is to take a fresh razor blade and follow the printing of the board and remove as much as you can. This is very time consuming but it will save you money on acids due to scraping the gold into a smaller quantity. I personally would not do it if there were hundreds of boards but for a few and experimenting it saves space and money. If not, sell on eBay [adv: electronic scrap on eBay].
Holly Figueroa- Houston, Texas
2005
2005
A. For those that are trying to refine electronics, maybe this will help you. I use this process for refining all gold including electronics.
1. put 5 lbs scrap in to a heatable container and add 1 quart of HNO3 (nitric acid) 70% tech grade is ok.
2. let acid work until there is no more reaction.
3. add 3 quarts of HCl (hydrochloric acid) muriatic acid
⇦this on
eBay or
Amazon [affil links] is ok.
4. let set and work until there is no solid metallics left.
5. add the leach solution to clean warm water, and add 1 to 1 1/2 pound of urea to solution and stir to help dissolve, this kills and neutralizes the nitric acid.
6. add 1 and 1/2 teaspoon of sodium sulfite for each ounce of total metals dissolved, (not just gold). the gold will filter out as brown particles that look like mud, this is 999.3 fine gold. filter wash and dry then melt.
I hope this has helped you.
- Enid, Oklahoma
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Ed. note: See also letter 771b for more discussion on recovery of components and precious metals from electronic scrap.
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