Chemical Aqua Regia Completion

[IThinkSilver]

I used AR to process some RAM chips. Since I didn’t know how much gold was there, I added aziotropic nitric acid drop by drop. In total I added about 10 drops, less than 1/2 ml. I filtered the AR and ended up with about 1000 ml after hydration with distilled water. I took a 100 ml sample of the AR and tried to precipitate with SMB but nothing happened except solution turned colorless. Assuming there was excess nitric, I added about 6 spoons of clean gold foils until no more would dissolve. Again, I took 100 ml sample and same results as first try. Upon consulting Hoke, I boiled the AR down to about 150 ml of thick brownish golden liquid. Then, I added HCL to react with any remaining nitric. So here I am now at this point, not sure how to proceed. Solution is in 2 L beaker. I have seen some recommend using sulfamic acid to correct pH I think. What steps are left to get the AR solution ready for SMB?

 

[Yggdrasil]

I used AR to process some RAM chips. Since I didn’t know how much gold was there, I added aziotropic nitric acid drop by drop. In total I added about 10 drops, less than 1/2 ml. I filtered the AR and ended up with about 1000 ml after hydration with distilled water. I took a 100 ml sample of the AR and tried to precipitate with SMB but nothing happened except solution turned colorless. Assuming there was excess nitric, I added about 6 spoons of clean gold foils until no more would dissolve. Again, I took 100 ml sample and same results as first try. Upon consulting Hoke, I boiled the AR down to about 150 ml of thick brownish golden liquid. Then, I added HCL to react with any remaining nitric. So here I am now at this point, not sure how to proceed. Solution is in 2 L beaker. I have seen some recommend using sulfamic acid to correct pH I think. What steps are left to get the AR solution ready for SMB?

Welcome.
Have you already read Hokes book?

If not, it's here with other important links to study:

We ask our new members to do 3 things.
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: https://goldrefiningforum.com/phpBB3/viewtopic.php?f=54&t=19798
2. Then read the safety section of the forum: https://goldrefiningforum.com/threads/library-index-thread.22351/post-233795
3. And then read about "Dealing with waste" in the forum: https://goldrefiningforum.com/threads/library-index-thread.22351/post-233794

Suggested reading:
https://goldrefiningforum.com/forums/the-library.101/
https://goldrefiningforum.com/threads/when-in-doubt-cement-it-out.30236/
https://goldrefiningforum.com/threa...le-read-this-before-you-post-about-ore.35743/

Video section: https://goldrefiningforum.com/threa...our-visual-learning-members.35185/post-379931

List of abbreviations: https://goldrefiningforum.com/threads/a-glossary-of-common-terms.21242/post-219169

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

 

[Yggdrasil]

I used AR to process some RAM chips. Since I didn’t know how much gold was there, I added aziotropic nitric acid drop by drop. In total I added about 10 drops, less than 1/2 ml. I filtered the AR and ended up with about 1000 ml after hydration with distilled water. I took a 100 ml sample of the AR and tried to precipitate with SMB but nothing happened except solution turned colorless. Assuming there was excess nitric, I added about 6 spoons of clean gold foils until no more would dissolve. Again, I took 100 ml sample and same results as first try. Upon consulting Hoke, I boiled the AR down to about 150 ml of thick brownish golden liquid. Then, I added HCL to react with any remaining nitric. So here I am now at this point, not sure how to proceed. Solution is in 2 L beaker. I have seen some recommend using sulfamic acid to correct pH I think. What steps are left to get the AR solution ready for SMB?

I'd like some clarification on your material.
Ram Chips, means in this setting the whole stick or the only the chips?
How many was there?

AR is not suitable for PCB stripping.

 

[IThinkSilver]

I'd like some clarification on your material.
Ram Chips, means in this setting the whole stick or the only the chips?
How many was there?

AR is not suitable for PCB stripping.

Only the chips, about 200 grams. They were calcined and then ground and filtered in distilled water. Then base metals were removed in nitric boil. Material then washed with distilled water. Then boiled in Aqua Regia and that was filtered to get a clear golden AR solution.

 

[Yggdrasil]

Only the chips, about 200 grams. They were calcined and then ground and filtered in distilled water. Then base metals were removed in nitric boil. Material then washed with distilled water. Then boiled in Aqua Regia and that was filtered to get a clear golden AR solution.

Was it ashed properly so there were no more black in the material?
You added enough Nitric to dissolve around 0.5 grams of pure Gold.
If there were still base metals left, less, since the base metals usually need more Nitric.
And at 1000ml the drop might have been invisible.
Did you let the solution stand over night to let it settle?