Failed Drop With Unexpected Results.

[Striker578]

This was my 3rd experiment with plated gold electronic waste. This batch was soft flexible plating so first I burned off the plastics, rinsed then processed 52g of material with 150 ml of AR. All was going well until after filtering & testing. I DeNOx with sulfamic acid and diluted. Upon adding SMB (strong sulfur smell)it failed to drop. I decided to cement it out with copper. I let it stay in for. 36 hours and filtered the cement. While filtering the last I accidentally picked up a beaker that had some used stock pot liquid in it and added it by accident. Instant color change to a two density layer fluid, one Red & the other Greenish Blue. I put the failed drop in a separate container to determine what element I have and handle appropriately. Thanks in advance

BEAKER ELEVATED FOR PICTURES>
1st picture > unmixed, top is stock pot. bottom layer is failed drop
2nd picture mixed layers, no sediments

 

[Lino1406]

This was my 3rd experiment with plated gold electronic waste. This batch was soft flexible plating so first I burned off the plastics, rinsed then processed 52g of material with 150 ml of AR. All was going well until after filtering & testing. I DeNOx with sulfamic acid and diluted. Upon adding SMB (strong sulfur smell)it failed to drop. I decided to cement it out with copper. I let it stay in for. 36 hours and filtered the cement. While filtering the last I accidentally picked up a beaker that had some used stock pot liquid in it and added it by accident. Instant color change to a two density layer fluid, one Red & the other Greenish Blue. I put the failed drop in a separate container to determine what element I have and handle appropriately. Thanks in advance

BEAKER ELEVATED FOR PICTURES>
1st picture > unmixed, top is stock pot. bottom layer is failed drop
2nd picture mixed layers, no sediments

Assuming the solution is acidic, check with stannous chloride for presence of gold. Seems to be very low

 

[Striker578]

Stannous test does show little gold. I assume most is in cement with other metals. Could the color be platinum or palladium? I let the sample beaker sit overnight & it had settled into a black cement. Is it possible that the addition of the stock pot fluid, (copper nitrate?) changed the PH causing the drop? I plan to filter & dry the cement before proceeding to the main extraction.

I'm thinking about boiling dry and starting over if I cannot get a successful drop..

.

 

[Martijn]

Can you show a picture of that stannous test?
From 52 grams of e-waste, I think you can expect about 0.1 gram of gold, which is very little to see as sediment layer. It may stay suspended it solution for a long time.

 

[BGDOCK]

Stannous test does show small very little gold. I assume most is in cement with other metals. Could the color be platinum or palladium? I let the beaker sit overnight & will check it again for sediments.
I'm thinking about boiling dry and start over.

You might want to put that in your stock pot and catch the gold when processing the stock pot at a later date.
Get some painters tape and label your jars , beakers ,etc.

Jeff

 

[Striker578]

Can you show a picture of that stannous test?
From 52 grams of e-waste, I think you can expect about 0.1 gram of gold, which is very little to see as sediment layer. It may stay suspended it solution for a long time.

The top right picture is after 1 minute & the bottom right is after 15 seconds with fresh Stannous.
The second picture is the filtered sediment after 24 hrs.
Third picture empty Plated test beaker.
I decided to test again. Took a 10 mL sample of the yellow/green failure and added about 2 mL of the blue stock pot liquid with same results. I tested the stock with stannous and it has very little gold. I think I need to get my PH and test to see the level.

 

[Yggdrasil]

The top right picture is after 1 minute & the bottom right is after 15 seconds with fresh Stannous.
The second picture is the filtered sediment after 24 hrs.
Third picture empty Plated test beaker.
I decided to test again. Took a 10 mL sample of the yellow/green failure and added about 2 mL of the blue stock pot liquid with same results. I tested the stock with stannous and it has very little gold. I think I need to get my PH and test to see the level.

So these smears are your Stannous tests?
These are practically unreadable.
Use some clean paper strips or cotton buds in stead, much easier to distinguish.
To my eyes these pictures show no Gold nor plating in the beaker, just smudges of dirt.

What was your source ? Soft plated plastic seem strange. Where did it come from?

There should be no need of filtering if it is Gold in solution, Gold will sink very fast if clean slower if dirty or dilute.
But it will sink.
You gave no description on how the Sulfamic acid was used and how it looked. (If no excess of Nitric, no need for Sulfamic).
How did the SMB behave besides smelling of Sulfur, or SO₂?

 

[Striker578]

I shall repeat the stannous s test on Q-Tips then retake picture and post.
Adding the sulfulmic (3tbs. spoonsful) and fizz reaction that reduced in size. Smell is a mix between HCL and Sulfur with HCL the strongest of two.. Upon adding SMB the reaction was fizzing with Brown Particles forming on top of the fizz then redissolvng. Continued to add SMB and noticed that no precipitation. Added more SMB no change. Stopped process and sought help as I didn't want to add too much. Very little NO3 was used due to small amount of gold.
I have no problem with Silver and am just starting with Gold. When unexpected happens I seek advice with study.
The material was Cable Ends flexible plated hardware that was incinerated first.

 

[Yggdrasil]

I shall repeat the stannous s test on Q-Tips then retake picture and post.
Adding the sulfulmic (3tbs. spoonsful) and fizz reaction that reduced in size. Smell is a mix between HCL and Sulfur with HCL the strongest of two.. Upon adding SMB the reaction was fizzing with Brown Particles forming on top of the fizz then redissolvng. Continued to add SMB and noticed that no precipitation. Added more SMB no change. Stopped process and sought help as I didn't want to add too much. Very little NO3 was used due to small amount of gold.
I have no problem with Silver and am just starting with Gold. When unexpected happens I seek advice with study.
The material was Cable Ends flexible plated hardware that was incinerated first.

Please check your spelling thoroughly with regard to chemicals.
When the Sulfamic acid was used was the solution hot, about 90 centigrade?
Very little HNO₃ or Nitrates?
Can you quantify very little, 1ml or 10 ml?

Your description on the behavior of the SMB indicates excess Nitric.
Sometimes it is best to add the SMB dissolved in water to make sure it reacts with the liquid and don't just hiss on the surface.
Or add it in small lumps.

 

[Martijn]

That looks more brown to me which indicates copper. The second one has a faint purple tint to it but I'm not sure.

 

[malou]

Good day!
I badly needed help with this.

We have sand and stone with high % of Au by assay. These are not nature nor scrap, but mined treasure that is an unprocessed form.
I tried the AR method to seperate the gold. I had obtained a rich gold solution- dark orange/tea in color and stannous test is (+), I had used urea to neutralize then SMB to precipitate. The solution become very cold upon addition of SMB, there was white foam, and the solution became yellow to pale yellow....then back to its original dark orange/tea color. I am not sure if I had neutralized it well with urea or what as I am very new to this. I just followed process from research.

Your help/inputs will be highly appreciated.

 

[Yggdrasil]

Good day!
I badly needed help with this.

We have sand and stone with high % of Au by assay. These are not nature nor scrap, but mined treasure that is an unprocessed form.
I tried the AR method to seperate the gold. I had obtained a rich gold solution- dark orange/tea in color and stannous test is (+), I had used urea to neutralize then SMB to precipitate. The solution become very cold upon addition of SMB, there was white foam, and the solution became yellow to pale yellow....then back to its original dark orange/tea color. I am not sure if I had neutralized it well with urea or what as I am very new to this. I just followed process from research.

Your help/inputs will be highly appreciated.

Welcome to us.
I think you need to recheck your chemicals, it will NOT get cold from SMB.
Anyway a few questions and comments.
How do you prepare your AR?
Urea is not recommended for deNOxing AR, better not overuse Nitric or use Sulfamic acid.

AR is not recommended for ores, at least not until you have a full assay.
Even then only for the richest and under special conditions.

But first we need you to study so you don't injure yourselves or others.
The Gold don't go anywhere.

1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: Screen Readable Copy of Hoke's Book
2. Then read the safety section of the forum: Safety
3. And then read about "Dealing with waste" in the forum: Dealing with Waste

Suggested reading: The Library

https://goldrefiningforum.com/threads/gold-refining-forum-rules.31182/

 

[malou]

Welcome to us.
I think you need to recheck your chemicals, it will NOT get cold from SMB.
Anyway a few questions and comments.
How do you prepare your AR?
Urea is not recommended for deNOxing AR, better not overuse Nitric or use Sulfamic acid.

AR is not recommended for ores, at least not until you have a full assay.
Even then only for the richest and under special conditions.

But first we need you to study so you don't injure yourselves or others.
The Gold don't go anywhere.

1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: Screen Readable Copy of Hoke's Book
2. Then read the safety section of the forum: Safety
3. And then read about "Dealing with waste" in the forum: Dealing with Waste

Suggested reading: The Library

https://goldrefiningforum.com/threads/gold-refining-forum-rules.31182/

Thank you very much for the warm welcome.

Yes, the solution is very cold after addition of SMB, as if the beaker came out of the fridge that there is condensation around it. So I tried to look online if I can find another grade that is for gold precipitation as I only see food grade. I dont know if they are the same.

My AR is 4 portion of HCl and 1 portion of HNO3, since there is no available pure HCl, I used the industrial grade muriatic acid only which is store bought. May I also ask, how will I know if I overused Nitric?

Thank you for the recommended book, I think this would help me a lot.

 

[Yggdrasil]

Thank you very much for the warm welcome.

Yes, the solution is very cold after addition of SMB, as if the beaker came out of the fridge that there is condensation around it. So I tried to look online if I can find another grade that is for gold precipitation as I only see food grade. I dont know if they are the same.

My AR is 4 portion of HCl and 1 portion of HNO3, since there is no available pure HCl, I used the industrial grade muriatic acid only which is store bought. May I also ask, how will I know if I overused Nitric?

Thank you for the recommended book, I think this would help me a lot.

Start studying first.

I think you have swapped the Urea and the SMB.

Any SMB is good.

Regarding the AR, looking at your mix tells it all.

We use AR like this:
Add HCl(Muriatic) enough to cover our material and heat it to hot but not boiling,
then add a little by little until no more reaction, add a bit more HCl if no more reaction a drop or three with Nitric.
If no more reaction it is done.
Then while it s hot around 90Centigrade we add Sulfamic acid until no fizzing/foaming.
The solution is then cooled and diluted with eaqual amount of water and filtered as cold as possible.
Next the solution needs to be crystal clear, the the Gold is dropped by SMB.
Siphon off the liquid after it test negative with Stannous. Pour the liquid in your stock pot.
Wash and boil the powder with water and HCl until the wash is colorless.
Re-refine the powder and repeat the procedure.
Your Gold should now be at least 99%+

Edit for spelling

 

[malou]

Thank you very much.

I will start with this steps and see how will it turn out. I'm hoping so much that I'll get it right this time. I'll be back for updates, and for sure some questions,with my trials.