Processing Fingers with CuCl2 etching solution

[Sungil JEON]

Just a guess, you did not eliminate the free nitric acid, that may be gold trying to precipitate.

Hello butcher.

Thank you for your advice.

Then do I have to neutralize? with urea?

 

[g_axelsson]

2. Filtering(I got 3.4g Gold foil)
3. HCl(150ml) + H2O(150ml) + Gold foil(heated until 70℃)
then plus HNO3 5ml( then stayed 12 hours)
4. Plus more HNO3(10ml) : but no change
(then after 12 hours) plus HNO3(35ml) : but no change
5. Filtering → this is No. 1 solution

You used way too much acid. To dissolve the gold foils you need 3 ml HCl + 1 ml HNO₃ per gram of gold according to theory. Follow these instructions next time.
A more practical way is just to add enough HCl to cover the foils as that will be more than enough, the extra HCl doesn't hurt the process.
Then add 1/2 - 2/3 of the needed nitric acid and watch the process. Depending on how much gases is reabsorbed by the liquid, temperature and so on, the nitric will dissolve more or less of your gold. After ten minutes add small amount of more nitric if it is needed, be patience as chemical reactions takes time.

When all gold is dissolved you shouldn't have that much excess nitric in your solution.
Excess nitric can be eliminated by Harolds "gold button" trick, denoxing by evaporation or by adding sulfamic acid. Use the green words together with denoxing in the search and you should find enough help. All this should have been covered in the introduction, did you read Lazersteves introduction to the forum and followed each link?

For your current situation, I agree with Butcher, you haven't denoxed your solution, there is still a lot of nitric acid and any precipitated gold is immediately dissolved again.

I don't see you mention testing? Do you have stannous chloride? Without it you might try to get gold from a solution that doesn't contain gold. Read up on testing for gold in solution with stannous chloride.

What I don't understand is step 3 and 4 where you claim no change? Do you still have your gold foils? They should have gone into solution at the first step. Are you sure you have nitric acid? Can you dissolve copper with your nitric acid? If you test your nitric acid with copper make it a small test, it reacts violently and emits toxic red fumes.

Be safe!

Göran

 

[Sungil JEON]

2. Filtering(I got 3.4g Gold foil)
3. HCl(150ml) + H2O(150ml) + Gold foil(heated until 70℃)
then plus HNO3 5ml( then stayed 12 hours)
4. Plus more HNO3(10ml) : but no change
(then after 12 hours) plus HNO3(35ml) : but no change
5. Filtering → this is No. 1 solution

You used way too much acid. To dissolve the gold foils you need 3 ml HCl + 1 ml HNO₃ per gram of gold according to theory. Follow these instructions next time.
A more practical way is just to add enough HCl to cover the foils as that will be more than enough, the extra HCl doesn't hurt the process.
Then add 1/2 - 2/3 of the needed nitric acid and watch the process. Depending on how much gases is reabsorbed by the liquid, temperature and so on, the nitric will dissolve more or less of your gold. After ten minutes add small amount of more nitric if it is needed, be patience as chemical reactions takes time.

When all gold is dissolved you shouldn't have that much excess nitric in your solution.
Excess nitric can be eliminated by Harolds "gold button" trick, denoxing by evaporation or by adding sulfamic acid. Use the green words together with denoxing in the search and you should find enough help. All this should have been covered in the introduction, did you read Lazersteves introduction to the forum and followed each link?

For your current situation, I agree with Butcher, you haven't denoxed your solution, there is still a lot of nitric acid and any precipitated gold is immediately dissolved again.

I don't see you mention testing? Do you have stannous chloride? Without it you might try to get gold from a solution that doesn't contain gold. Read up on testing for gold in solution with stannous chloride.

What I don't understand is step 3 and 4 where you claim no change? Do you still have your gold foils? They should have gone into solution at the first step. Are you sure you have nitric acid? Can you dissolve copper with your nitric acid? If you test your nitric acid with copper make it a small test, it reacts violently and emits toxic red fumes.

Be safe!

Göran

Thank you for your kind advice.
In fact I'm thoroughly confused.
I thought that I followed all steps like video.
So I looked forward to dissolve of gold foil.
But I can't see that.
I'll follow your advice and I'll tell the result.
Thank you!

 

[butcher]

Sungil JEON,

Göran gave excellent advice.

You will constantly struggle and be confused if you try to learn refining by just following a few videos, it take study to understand them and to learn to recover and refine metals, the videos can be helpful to see some of the reactions, but without the study to know how to recover and refine they can almost be meaningless.

Research the problem you have now, and keep up with your study this is where you will learn, the videos are only a tiny bit of that learning process.

Personally I would forget about using urea (besides maybe a few prills for testing), it does not work that well and it can be dangerous. If you need a reagent to de-NOx a solution use sulfamic acid it is the answer, (it also is beneficial if lead is involved), although you will still be much better off using the nitric acid wisely, and do not use any more than needed to get the job done.

For foils or gold powders, HCl acid (hydrochloric acid) and sodium hypochlorite (bleach), or the HCl acid and 32% H2O2, I believe are better to use than aqua regia (HCl acid and nitric acid), it is much easier to deal with a little excess oxidizers, and for me it is also much cheaper to use.

Keep studying the more you learn the easier it gets and the less problems or confusion you will have, then the video's will make more sense, and can be a helpful guide.

 

[samuel-a]

Sungil JEON,

Hello and welcome to the forum. You seems to be on the right path to recover and refine gold.

My understanding of your problem (as Goran mentioned) is that you are adding Nitric acid but the gold foils just won't dissolve. If that's case, i would strongly recommand you to check the reagents you are working with. Make sure you really do use Hydrochloric acid, make sure you really do use Nitric acid, Make sure your SMB is indeed Sodium Metabisulfite, make sure your Stannous Chloride can really test gold.

If you were indeed able to dissolve the gold foils, with hot HCl + Nitric, then i can guarantee 100% you did not followed the video presentation and the full tutorial on my website (you have read it, right?) as well as you thought. If that's the case, besides keep on reading here, i would encourage you to watch the video and read the tutorial again and compare with your lab notes.
The main point, you should not have used so much nitric (if it really is nitric).


I agree with butcher, the videos i make and upload (and other's too) are supposed to be complementary to the tutorials i write on my website, otherwise i wouldn't have invested so much time writing them. Point is, there's only so much one can stuff in a video. While in text, things tend to get much more detailed. On the other hand, there are things one can write about all day long, but an actual presentation of it is many many times more effective.
The above, is of course not a substitute to actually learn the basics, before (or while) reading Hoke book and the forum, one should gain some basic knowladge in chemistry, laboratory techniques and materials safety.

However and inspite the above, i really do feel (No bragging!) that my video presentation + tutorial on this subject is probably the most comprehensive anyone can find for free (and maybe even amongst the ones you have to pay for).

To summerize, i look forward seeing your gold button. :mrgreen:

 

[Sungil JEON]

Sungil JEON,

Göran gave excellent advice.

You will constantly struggle and be confused if you try to learn refining by just following a few videos, it take study to understand them and to learn to recover and refine metals, the videos can be helpful to see some of the reactions, but without the study to know how to recover and refine they can almost be meaningless.

Research the problem you have now, and keep up with your study this is where you will learn, the videos are only a tiny bit of that learning process.

Personally I would forget about using urea (besides maybe a few prills for testing), it does not work that well and it can be dangerous. If you need a reagent to de-NOx a solution use sulfamic acid it is the answer, (it also is beneficial if lead is involved), although you will still be much better off using the nitric acid wisely, and do not use any more than needed to get the job done.

For foils or gold powders, HCl acid (hydrochloric acid) and sodium hypochlorite (bleach), or the HCl acid and 32% H2O2, I believe are better to use than aqua regia (HCl acid and nitric acid), it is much easier to deal with a little excess oxidizers, and for me it is also much cheaper to use.

Keep studying the more you learn the easier it gets and the less problems or confusion you will have, then the video's will make more sense, and can be a helpful guide.

Thank you for your advice!
Thank you very much!

 

[Sungil JEON]

Sungil JEON,

Hello and welcome to the forum. You seems to be on the right path to recover and refine gold.

My understanding of your problem (as Goran mentioned) is that you are adding Nitric acid but the gold foils just won't dissolve. If that's case, i would strongly recommand you to check the reagents you are working with. Make sure you really do use Hydrochloric acid, make sure you really do use Nitric acid, Make sure your SMB is indeed Sodium Metabisulfite, make sure your Stannous Chloride can really test gold.

If you were indeed able to dissolve the gold foils, with hot HCl + Nitric, then i can guarantee 100% you did not followed the video presentation and the full tutorial on my website (you have read it, right?) as well as you thought. If that's the case, besides keep on reading here, i would encourage you to watch the video and read the tutorial again and compare with your lab notes.
The main point, you should not have used so much nitric (if it really is nitric).


I agree with butcher, the videos i make and upload (and other's too) are supposed to be complementary to the tutorials i write on my website, otherwise i wouldn't have invested so much time writing them. Point is, there's only so much one can stuff in a video. While in text, things tend to get much more detailed. On the other hand, there are things one can write about all day long, but an actual presentation of it is many many times more effective.
The above, is of course not a substitute to actually learn the basics, before (or while) reading Hoke book and the forum, one should gain some basic knowladge in chemistry, laboratory techniques and materials safety.

However and inspite the above, i really do feel (No bragging!) that my video presentation + tutorial on this subject is probably the most comprehensive anyone can find for free (and maybe even amongst the ones you have to pay for).

To summerize, i look forward seeing your gold button. :mrgreen:

Thank you very much!
Frankly speaking I'm really confused.
I'm not familiar with this page.
(I don't know that I'm writing this message here. )
Anyway I'll try and I'll let you know my results.
Thank you.

 

[maynman1751]

What percent (concentration) are your HCl and your HNO3? If your acids are of a weak concentration it will result in poor dissolution of your foils. It is preferred to have 30-32% HCl and 50-70% HNO3. If you don't have these it will take some adjusting to get the right combination.
You should do as advised and do some serious research and studying before venturing further. These procedures can be very confusing if you don't know the variables involved. It's not as simple as A+B=C. Do your homework and you will succeed. I studied this forum and read the suggested materials for nearly a year before doing anything other than the getting acquainted experiments.
Like Harold says: Read Hokes book and then read it again until you understand it!!!!!!

 

[Sungil JEON]

This is the last question.
(I just saw that this directory is not allowed to questions. sorry!)

Yesterday I did something.
I used Urea to to reduce too much nitric acid.
And the result is in photos.
....
What's this???

 

[samuel-a]

Please, test your solution with SnCl2 before you proceed.

 

[niteliteone]

Looks like the solution is a little too concentrated for what is in it.
Add a little water (h20) and a little heat, then stir. The crystals will dissolve back into solution.

Get rid of the Urea, it has NO good use in refining. :roll:

 

[Pantherlikher]

Hello Sungil JEON and welcome.

Can you understand english or are you using a translater, hopefully a good translater.

READ the answers given to you!

May I strongly tell you to do nothing? STOP what you are doing, put a lid on the containers.

Translate and read and learn what you are doing. Please?

Read here in the forum and learn what steps you need to learn before you hurt yourself.
Are you doing this inside your house?

This is very dangerous and you could get hurt or hurt someone else.
Learn what to do and why.

B.S.

 

[butcher]

Urea + nitric acid can make a salt of urea nitrate, which can be dangerous if heated.

Urea can also decompose to ammonia or ammonium compounds, these can be dangerous with metals like gold.

At this point I would cement the values out of solution with copper.
study dealing with waste in the safety section, to treat the waste.

And then study before proceeding with recovery or refining, to get an understanding of the processes and dangers.

 

[Sungil JEON]

Hello dear.

Today I want to show you my 3rd results. And I would to listen all of your advice.

I'll show you my experiment steps.

1. I prepared PCB scrap (mainly cellular phone battery) : 211.3 g
2. (HCl 800ml + H2O 650ml) + (CuCl2 20g + H2O 400ml) + PCB scrap + Air pump
3. Gold Foil from step 2.
4. HCl 30ml + H2O 10ml + Gold foil(step 3) + heating 90℃
5. Step 4. + HNO3 3ml
6. after 15 minutes HNO3 2ml
7. after 15 minutes HNO3 2ml
8. after 15 minutes HNO3 1ml
9. Filtering step 8.
10. Ice cube + step 9. + H2SO4 15ml
11. Filtering step 10.
12. add SMB 4g to step 11.(at 20℃)
13. Picture in here

Questeion> Is this a gold? I wanted to get precipitate. But I just got soft powder and this. I think that I follwed whole steps.

I want to say more things. but my english is too short. understand me please.
Thank you for reading.

 

[g_axelsson]

That looks like gold on the surface. Just knock it down by spraying it with some water from a spray bottle.

Göran

 

[Clneal2003]

2. Filtering(I got 3.4g Gold foil)
3. HCl(150ml) + H2O(150ml) + Gold foil(heated until 70℃)
then plus HNO3 5ml( then stayed 12 hours)
4. Plus more HNO3(10ml) : but no change
(then after 12 hours) plus HNO3(35ml) : but no change
5. Filtering → this is No. 1 solution

You used way too much acid. To dissolve the gold foils you need 3 ml HCl + 1 ml HNO₃ per gram of gold according to theory. Follow these instructions next time.
A more practical way is just to add enough HCl to cover the foils as that will be more than enough, the extra HCl doesn't hurt the process.
Then add 1/2 - 2/3 of the needed nitric acid and watch the process. Depending on how much gases is reabsorbed by the liquid, temperature and so on, the nitric will dissolve more or less of your gold. After ten minutes add small amount of more nitric if it is needed, be patience as chemical reactions takes time.

When all gold is dissolved you shouldn't have that much excess nitric in your solution.
Excess nitric can be eliminated by Harolds "gold button" trick, denoxing by evaporation or by adding sulfamic acid. Use the green words together with denoxing in the search and you should find enough help. All this should have been covered in the introduction, did you read Lazersteves introduction to the forum and followed each link?

For your current situation, I agree with Butcher, you haven't denoxed your solution, there is still a lot of nitric acid and any precipitated gold is immediately dissolved again.

I don't see you mention testing? Do you have stannous chloride? Without it you might try to get gold from a solution that doesn't contain gold. Read up on testing for gold in solution with stannous chloride.

What I don't understand is step 3 and 4 where you claim no change? Do you still have your gold foils? They should have gone into solution at the first step. Are you sure you have nitric acid? Can you dissolve copper with your nitric acid? If you test your nitric acid with copper make it a small test, it reacts violently and emits toxic red fumes.

Be safe!

Göran

I tried using an older button - I say button but it was really more of a BB ROLLING AROUND - in my AR tonight and the nitric came off perfectly. My question is about the condition of my used button. I dropped it in the AR with the silver chloride scum at the bottom and now my old button has little specks of silver chloride stuck to it. Should I have filtered the ar first to remove the scum before I added the old gold button?

Thanks.

 

[g_axelsson]

You should be able to wipe the silver chloride off unless the silver came from your BB.

Göran

 

[Clneal2003]

Yeah it rubs off... But it's a very small BB and a pain in the butt to clean. I just locked it back up for time being. I wonder if Sunjil ever got his gold back out? His last post was February.

 

[FrugalRefiner]

Yeah it rubs off... But it's a very small BB and a pain in the butt to clean.

You can dissolve the silver chloride off the BB with a little ammonia. Then remove your BB and add HCl to the ammonia to acidify it and reprecipitate your silver as silver chloride again.

Dave

 

[purgatory]

Hi,
How are you all doing?
Well, i'm new here and this is going to be 1st post reply/post.
I just saw Sam's video and appreciated a lot.
Actually I joined this forum tonigh, a way toooo late, as I have processed a 1st batch of 10 kilos of mixed Memory Sticks, which went pretty bad. I only recovered 2.3 grams of pure gold out of 10 kilos of Ram Sticks, forgot to weight gold fingers.
I used 60% nitric acid with de-ionized water to strip off the gold foils from fingers. I used 1:2 ratio, 1 part acid 2 parts de-ionized water.
All the gold foils were removed completely.
I washed them thoroughly with de-ionized water and put them in a beaker and covered the foils with hcl commercial grade and added few drops of nitric acid, the reaction begun and this aqua regia started to dissolve gold instantly, a few more drops of nitric acid were added to get the foils dissolved completely, all the foils were dissolved, I did not add no heat to the solution as the atmospheric temperature were nearly 40* C.
I filtered the solution containing gold with the filter paper, the colour of the solution was bright yellow and was crystal clear.
I added some de-ionized water to dilute it a bit for the easy filteration.
I added some Urea which was 98% pure, there was a little reaction upon Urea addition but no brown or red fumes noticed, at that point I thought the nitic acid has been neutralized. Having this thought in my mind I proceeded to the addition of SMB.
I added a table spoon of Sodium Metabisulfite 98% pure (made in Germany) by Merck.
There was a violant reaction upon it's addition, I thought may be its the nitric acid reacting with SMB, I added 2 more spoons of SMB.
After the 1st addition of SMB the colour of the solution changed to brown and the gold powder started to precipitate instantly, I left the solution over night and the next morning the colour of the solution was almost colourless and the gold was precipitated at the bottom of the beaker, I filtered te solution using filter paper and washed the gold powder well with de-ionized water then with hcl and at last again with de-ionized water and melted it along with the filter paper which I used at the end of filtering the gold powder after precipitation.
I dont know where I made mistake or a lot of mistakes.
It was 1st attempt to recover gold from e-waste.
Can anyone help me regarding my next attempt?
After my 1st experiment I started to read this forum for about a month or so and read a lot of post and replies from Sam, Buther, Geo and many more.
I visited lazersteve's website and watched his videos.
I have been reading Hoke's book also.
I have around 50 lbs of more Mixed Ram sticks and around 8 lbs of ic chips from Ram Sticks.
Around 150 lbs of computer P4 and P3mother board.
1860 pieces of P4 processors.
2 pounds of mix ceramic processors.
Telecom boards containg a lot of square ics with gold arrow mark.
2 pounds of Monolithic capacitors.
Around 1lb of gold plated pins from different connectors.
6 lbs of mixed mobile motherboards.
I'm completely confused as I have invested around $2000/= over this scrap.

Please can anyone help me recovering gold from the above mentioned scrap?
I would like to restart from gold fingers as I will cut the gold fingers off from the Ram Sticks and would like to process the Ic chips from Rams after gold fingers.
Each and every reply from the respected members will be highly appreciated.
Thanks a lot.
Alvi