Letter 18889 page 2

Removing gold from electronics

I am trying to find the easy way for separating copper from 14 kt. scrap? anything faster than sodium nitrate glass etc. and than cupeling this and breaking off the glass ect. ect.

Craig Griffin
hobbyist - Apple Valley, California, USA

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 Roberts
Hobbyist - Mesa, AZ, USA

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 Rotalsky
Hobbyist - Franklin, NC, USA

I am involve 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 Tong
Student - Singapore

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 Walters
HOBBYIST - Vanderbijlpark, GAUTENG, SOUTH AFRICA

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 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, TX, USA

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, TX USA

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 Nagl
hobbyist - Bayville, N.J., USA

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. Who should I contact?

Gregg Bremers
non-profit religious - Lincoln, NE, USA

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 Pridgen
hobbyist - Mobile, AL, USA

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, TN

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 minn
computer repair - Edmonton, KY, USA

The gold in the west electronics is very rare about 4 g/kg. But in the former Soviet Union and satellites the situation is different. Today I got 15 g 22 karat gold from a single computer, made before 22 years in Bulgaria, this is a gold mine. I understand that the old machines in the east Europe and Russia are gold mine!!!

Ivan Georgiev
designer - Sofia, SA, Bulgaria

Hi, I'm a business man engage 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 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 their 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 to for your help.

Alex Master
Scrap Buyer - Makati, Metro Manila, Philippines

I have used aquaregia 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 Luxmore
hobbyist - PEACHLAND , BC, CANADA

directed mostly to Richard Alcorn

Richard you mentioned making AR in situ with sodium nitrate and HCl. Can you elaborate on this a little more.

Thanks

Jim Wiggins
georgia elektrix - Atlanta, georgia

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 ic.s 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 Thier 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.

Doug Russell
- Lincolnton, NC, USA

Ed. note: I don't think it's fair to characterize the readers with "those who have the answers won't share them". Just on this one thread alone some exceptionally informative postings have been offered by Panjala Mukesh, Richard Alcorn, Peter Couture, Adrian Meador, and others.

Gold containing article is made anodic and is stripped electrolytically , or is immersed in the above mentioned solution of NaCN, NaOH, and SMNBS.

Panjala Mukesh      fashion jewelry mfgr. Hyderabad, India

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 Smith
amatuer - Montana, USA

Have removed most of gold and other metals from 32 yrs 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 was good thing been sitting here about 7 yrs. If you have suggestions please.
Thank You,
Kathy Doench
For Richard Alcorn

Kathy L Doench
- Cadiz, KY, USA

While there may have been 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 a 1973 computer probably won't buy 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. 
finishing.com
Brick, New Jersey

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.

Holly Figueroa
- Houston, TX, USA

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 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.

Maurice Robinette
- Enid, Oklahoma, USA

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Ed. note: See also letter 771b for more discussion on recovery of components and precious metals from electronic scrap. Please restrain discussion of this topic to these two threads. Sorry, we can't spawn additional threads on this topic, which is only peripherally related to our theme of industrial metal finishing.

I like everyone else it seems have several hundred pounds of motherboards, ethernet, etc scrap as well as telephone scrap that I need to process. What I have been doing is pulling the cpus and cutting fingers and selling via the internet. What I wonder is what is remaining on the boards and how do I remove it. I think the jumper pins, ide connector, pci slots, etc are gold plated but after many attempts at many methods I have yet to find a way to efficiently remove the pins from the boards. The worst seems to be the pci type slots that just won't let the pins come out of the assembly. Is there a product, acid mixture, or solvent that will dissolve the plastic material and leave only the metal pins? I remove the pin assemblies with a small Dremel tool just clipping the bottom of the leads but the plastic is a very big problem so far. Any help is very greatly appreciated!!! Thanks!!!

Chris Coleman
RGV Surplus - Weslaco, Texas, USA

Lots of people seem to be interested in doing this. I found a guy on eBay selling old chips and he said "gold recovery" and I did a little google search and ended up here.

From what it looks like, there is a very small amount of gold inside computers, certainly not enough to be worth your trouble as a private individual. There's probably more gold in a 1 liter bottle of Goldschlager than there is on a chip.

If you're a factory owner with hundreds of thousands of chips and machines, then that's a different story. But if you're looking for a get rich quick scheme, this isn't one of them. The cost of the chemicals greatly outweighs the value of the tiny bit of gold you're going to recover.

Zi Mei
- New York, NY

Hello,

If you have electronic scrap , sell it.
Chemical extraction is a dangerous business best left to professionals. And if you are entirely successful , you may only extract 40 to 50% of precious metals anyway.
If you have 40 tons.....sell it.
If you have 200 tons.....sell it.
If you are generating 100 tons monthly , sell it to someone who can make you an attractive offer or a licensed refiner. Of course you can enter into an agreement to get paid on settlement...but don't hold your breath...a bird in hand is worth two in the bush.
No one ever went broke making a profit.
No amount of money can compensate for your health.

Hope this helps.

Johnny K
- NY NY USA

To all the "Experts",
I am a firefighter/paramedic and have been a haz-mat instructor for the last 11 yrs. I have just started looking for info on this subject and it seems to me that all of the experts that post responses to questions would want to share their years of trial and error with the new comers so that they don't kill themselves or others. So far I am only seeing replies that contain just the right amount of info to make anyone trying this to be a danger to he or she and anyone that is within 100 yards of them. So, I challenge the experts to share the info with the rest of the world.

Thank you,
A very concerned newcomer.

william bemis
- campbellsville,ky United States

Please share your expertise and write down the steps for us to go save someone who is in a burning building, William :-)

Would you not urge people to call 911 instead? And if they have an abiding interest in the subject, then urge them to get hands-on training and qualification testing in lifesaving, read books on the subject, and don't attempt it unless they have the right equipment? That's exactly what I and many readers have done on this thread a dozen times and counting.

An internet posting is a "one room schoolhouse" with ten thousand people wandering in and out; some are 3rd graders and some are PhDs, some have decades of safety training and some haven't a clue, some are working in well established research labs and some are trying to work on their kitchen stove, some are your neighbors and some are desperate third-worlders clutching at any scheme to feed their starving children, not next week but today.

If they know enough about the subject to frame a specific question, I think the experts will answer it, but I think "full answers" that can make things safe for all readers is a total impossibility, and that all we can do is to continue to tell people not to work with hazardous chemicals without hands-on training in the subject and working in a proper industrial facility with the correct gear and PPE.

Ted Mooney, P.E. 
finishing.com
Brick, New Jersey

I think all these people inquiring about refining gold and silver from computer parts are all wasting their time. I agree with the general consensus that there is no significant amount of gold to be recovered from these sources. The health risks greatly outweigh the potential profit margin, if any at all. It amazes me to see people willing to risk their health, as well as the health of others in their immediate environments to get a tiny scrap of gold. Expending so much time and energy for the smallest returns. You could make far more money per week working at Mcdonalds and eat all the fattening food they sell for free. At least it would be a regular paycheck and even healthier for you too, if you can believe that. God help the get rich quick mind. Get a job, it pays more. Lol.

Ryan Maximus
- Stamford, Ct U.S.A.

Don't make the mistake of thinking that I condone an untrained person doing anything that is dangerous.

But to think that telling any person that has set there mind to something that they shouldn't do it, And believe that they will just stop ... Well your just kidding yourself. Doesn't it make more sense to properly inform them as to what they should do and warn them of the danger as well??? I know that anytime that a person has asked me how certain things are done in my job field I tell them how it's properly done and tell them how dangerous it truly is without the proper equipment and formal training. I also wonder how many people that have become outstanding Firefighters, EMT's, Paramedics, Haz-mat tech's, Swiftwater rescue tech's, Rope rescue tech's ect....
Would have just gave up. It comes down to this, No matter what you do to stop people from doing things that are hazardous to themselves or the ones around them, Your wasting time. The best you can ever expect to do is show them the proper and safest way and hope that they get formal training. Just food for thought.

William Bemis
- Campbellsville, KY, United States

And I will return again to an analogy to your line of work, William. People will go into a burning building to save their pets even though you tell them not to. So let me quote you --
" . . . And believe that they will just stop ... Well your just kidding yourself. Doesn't it make more sense to properly inform them as to what they should do and warn them of the danger as well??? . . . No matter what you do to stop people from doing things that are hazardous to themselves or the ones around them, Your wasting time. The best you can ever expect to do is show them the proper and safest way and hope that they get formal training." So please list the steps our readers should take in entering a burning building to save their pets if they insist on doing so.

Your first posting was right: people who are using these dangerous materials without hands-on training are "a danger to anyone within a hundred yards of them". People lacking a background in a subject and who will not get training at least should start by reading a book on that subject rather than expecting a one-paragraph internet answer. Otherwise, do we start by discussing fulminates? Or the dangers of perchloric acid? How to select goggles? Which respirator will be effective and which will prove useless for a given chemistry? How to dispose of the waste? The evolution of HCN gas from acidified cyanide? Heat of reaction? Treatment of chemical burns? Which safety topics do we omit?

Ted Mooney, P.E. 
finishing.com
Brick, New Jersey

Ted, First let me thank you for allowing me to have a voice here. Now then, This will be my final post. You guy's keep up the good work and keep me and all the other firefighter/medics in work.

William Bemis
- Campbellsville, KY

It would take far too long to acquire any decent amount of gold from electrical appliances, why not collect broken jewelry and when you have a sufficient amount for a small bar, melt it down using a crucible, these can be made or bought the electric crucibles work great although you can make one by using a oil drum cut down with a smaller drum in side and fill with concrete using fire proofing bore a small hole in lid attach a coupling to the wall and fit your gas supply using propane this is a hot burning clean gas, crucible goes inside with some borax powder and gold into the crucible and turn up the heat, about an hour later hey presto you got gold, advisable to melt the gold more than the melt heat for pouring, make sure you got a good bar mold preferably cast, you can make them out of clay or porcelain fired well, but these want last long,.

Paul Bates
pureinkuk - Doncaster

I too saw the Ebay sale for 10 lbs of "Recycling" CPUs and decided to research the topic. I am proud to say that I will NOT be attempting to conquer this chemistry experiment. I am smart enough to know NOT to try this. I'm sorry, but to spend $.80 to recover $1.20 in gold using toxic chemicals does not make sense to me. I can make more money cutting lawns!

Steve Demers
- Vero Beach, FL, USA

I in no way plan to even try this, but find it interesting that people would consider such a dangerous task. Lack of understanding to the dangers I think. One question. Why wouldn't you grid to a fine powder, then separate by weight, then just melt out the gold? Gold is so heavy it should seperate easily and I don't understand the need for all the chemicals. The melting process would probably still leach some pretty toxic gasses, but less then all the acid use, as the other substances could be removed before melting. Anyway just my two cents worth. Oh yeah, working at McDonalds would provide a better income, I agree.

Kevin Longbrake
- Marysville, Ohio

I have experience in recovering gold from a variety of sources but not specifically in e-scrap.I am posting this information on this board to see if any one has attempted the recovery process on e-scrap.

The process of gold recovery can be improved by treatment to recover or remove lead and tin.The scrap has to be burnt to remove plastics. This burning process will produce toxic fumes from the destruction of the plastics and the formation of toxic fumes of mecury,zinc oxide as well as arsenic and antimony oxides.Excellent ventilation is mandatory during this incineration step.The resulting solid material from the burning process,cinder or calcine as it is called is usually crushed and then leached with caustic solution to solubilise the lead and tin values contained in the e-scrap.This caustic dissolution step has to be done using protective suit,gloves and face shield because the caustic solution will produce a severe caustic burn.The fumes will damage your eyes or lungs if ingested. The lead and tin values are converted to soluble plumbate and antimonate respectively.This step should will also dissolve any arsenic and antimony in the e-scrap as arsenate and antimonates which are also very toxic.The residue from this stage obtained by filtration will contain copper, gold, silver and the Platinum group metals(PGM).This should reduce the weight reporting to copper, gold,silver and PGM recovery.The hot caustic solution free of any solids is treated with scrap aluminum beverage cans that have been stripped of the plastics by burning. This will produce metallic lead which will form as balls and will sink to bottom along with tin. During the process hydrogen evolution will occur and if not done in a location with excellent ventilation hydrogen explosions can possibly occur.The lead and tin are recovered by filtering. If the metals are not removed when the reaction is done they will go back into the caustic solution.After the lead and tin are removed the solution should be neutralised with muriatic acid to produce a neutral solution that is neither acid or basic for safe disposal.This is very important because if too much muriatic acid is used the solution will turn acidic and then there is the danger of produce Arsine and Stibnine gases which are also very toxic.

Gopalan Ramadorai
- Hillsboro, OR

If you have a lot of gold, you are in the gold refining business.

If you have a lot of copper, you are in the copper refining business.

Connectors comprise of mostly copper and very little gold. simple refine the copper using copper sulfate salt in aqueous solution with very little sulfuric acid for free acid.

The connector should wither away leaving the gold "glove".

The copper collected at the cathode is pure electrolytic copper.

Voltage should be low and current densities should be low as well to get a good plating.

Please note that decopperising is a long process and I do it in two stages. First stage, decopperise as fast as possible bulk connectors, fingers, etc. This will also turn the copper sulfate into iron sulfate as iron is exchanged by cementation. No worry, it still decopperised once the copper sulfate is gone.

Then take the copper "mud" and slowly refine it again. This should leave hard copper on the electrode and will remove impurities such as gold which was dropped in the first stage.

Once I'm left with decopperised gold "leaf", I send to refiner. The copper is sold as pure #1 copper.

The process is a continuous, renewable process.

Regards,

Alain Pelletier
- Edmundston, NB, Canada

I want to follow-up on or respond to this question publicly (in non-commercial fashion).

 

I want to post a question or inquiry on a different subject unrelated to recovery of precious metals from electronic scrap.