Hi, I have read mixed information as to what colors show for certain metals using stannous chloride. If anyone would be willing to give their opinion on these tests I'd really appreciate it!
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Stannous Questions
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Often tests are easier to read if you use paper strips or cotton buds, dipped in solution in stead of spoons, spot plates and similar.
Edit: spelling error
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Hello, Can anyone explain why my stannous test went from instant dark brown to clear/invisible in approx 2 seconds?
The quick answer is lack of gold. But it is possible you didn't apply the stannous properly, I've seen that when stannous was dropped into a reaction and the result was diluted. So please, detail how you tested.
It is kind of complicated (and procedurally messy) so I will be terse. I am a beginner and I want to be respectful of your time, so here goes:
1) In several iterations, I placed a couple of pounds of circuit boards and assorted gold plated devices (with significantly visible gold) in a beaker and used the Shor International Product (I know it is frowned upon here) to create AR. All went well and I observed plenty of purple stained stannous tests.
2) I then used urea (I know, that too is frowned upon here) to denox. I still had plenty of purple stained stannous tests. Frequent filtering the solution is implied here.
3) Dropped the gold with their product (Shor Quadratic Precipitant). So far, so good....had brown mud at the bottom of the beaker.
4) Cleaned mud with ammonia and then distilled water (as they suggested). Now everything goes south...
5) I attempted to refine this accumulated mud even further using the same procedures above. This left me with approx 3 gallons of green AR with no precipitant and NO gold in solution - all negative stannous tests.
6) I added lots of SMB and no change.
7) I then added clean copper pieces to the 5 gallon bucket (hoping to cement out the gold) and after a couple of weeks, I recovered quite a bit of brown precipitant.
8) I HCL rinsed it (warm) and Distilled rinsed it (warm) until it was clear - and then dried the brown powder.
9) I used the Shor Product (a nitric acid substitute) one more time with 10 grams of this newly acquired power - then heated it about a hour.
10) Then this Stannous test went from dark brown to clear in 2 seconds.
11) I know there is gold in there and I do not want to discard it.
Thanking you all in advance....
1) In several iterations, I placed a couple of pounds of circuit boards and assorted gold plated devices (with significantly visible gold) in a beaker and used the Shor International Product (I know it is frowned upon here) to create AR. All went well and I observed plenty of purple stained stannous tests.
2) I then used urea (I know, that too is frowned upon here) to denox. I still had plenty of purple stained stannous tests. Frequent filtering the solution is implied here.
3) Dropped the gold with their product (Shor Quadratic Precipitant). So far, so good....had brown mud at the bottom of the beaker.
4) Cleaned mud with ammonia and then distilled water (as they suggested). Now everything goes south...
5) I attempted to refine this accumulated mud even further using the same procedures above. This left me with approx 3 gallons of green AR with no precipitant and NO gold in solution - all negative stannous tests.
6) I added lots of SMB and no change.
7) I then added clean copper pieces to the 5 gallon bucket (hoping to cement out the gold) and after a couple of weeks, I recovered quite a bit of brown precipitant.
8) I HCL rinsed it (warm) and Distilled rinsed it (warm) until it was clear - and then dried the brown powder.
9) I used the Shor Product (a nitric acid substitute) one more time with 10 grams of this newly acquired power - then heated it about a hour.
10) Then this Stannous test went from dark brown to clear in 2 seconds.
11) I know there is gold in there and I do not want to discard it.
Thanking you all in advance....
This is difficult to answer because Shor labels it’s chemicals specifically so you do not know what you are using. One thing strange is you ended up with a brown mud after the first drop. Now if that was a normal aqua regia reaction, you would have digested the mud from the first drop and had a beautiful red acid if the material digested was gold. The fact that it was green is a red flag. As is the fact it did not indicate positive on stannous.
Did you ever test your stannous chloride with a small drop of solution you know contains gold. That is the first thing I do when a stannous test is negative and I expect differently.
I think a few members who have experience with the Shor process should comment here.
Did you ever test your stannous chloride with a small drop of solution you know contains gold. That is the first thing I do when a stannous test is negative and I expect differently.
I think a few members who have experience with the Shor process should comment here.
Three things here:
1) "One thing strange is you ended up with a brown mud after the first drop". Perhaps I wasn't clear.... the first few beakers of Shor AR mixed back in May of 2022 was golden color (after filtering). Then I dropped the gold with the Shor Product and recovered and rinsed the brown precipitant (which I called mud in the above post). I never saw a red liquid. That was back in May of 2022.
2) Fast forward to September 2022 where I am now .... I recovered the brown sediment from the bottom of the "pregnant bucket" weeks after the addition of the copper. This brown sediment is what puzzles me and caused me to start this thread.
3) I did not test the integrity of my stannous on a known gold solution.... However, I have another, newer bottle of stannous that I will try later today.
1) "One thing strange is you ended up with a brown mud after the first drop". Perhaps I wasn't clear.... the first few beakers of Shor AR mixed back in May of 2022 was golden color (after filtering). Then I dropped the gold with the Shor Product and recovered and rinsed the brown precipitant (which I called mud in the above post). I never saw a red liquid. That was back in May of 2022.
2) Fast forward to September 2022 where I am now .... I recovered the brown sediment from the bottom of the "pregnant bucket" weeks after the addition of the copper. This brown sediment is what puzzles me and caused me to start this thread.
3) I did not test the integrity of my stannous on a known gold solution.... However, I have another, newer bottle of stannous that I will try later today.
Red is with concentrated solution dilute will be yellowish.
Where did the copper come from?
You said nothing if copper?
Can you please go in detail what you have done?
Hello Yggdrasil,
"Can you please go in detail what you have done?"
Yes, Steps #1 - 10 listed above, are the details to the best of my recollection. Is there something
in particular that I need to further explain?
"Where did the copper come from? You said nothing if copper?"
I added high quality copper tubing to my 5 gallon AR bucket when I saw no precipitant and no gold in solution (#7 above).
When in doubt, cement it out?
Thank you.
"Can you please go in detail what you have done?"
Yes, Steps #1 - 10 listed above, are the details to the best of my recollection. Is there something
in particular that I need to further explain?
"Where did the copper come from? You said nothing if copper?"
I added high quality copper tubing to my 5 gallon AR bucket when I saw no precipitant and no gold in solution (#7 above).
When in doubt, cement it out?
Thank you.
Did you dissolve ALL base metals?
No comment.
All ok, but why use a product that is waay more expensive than the clean product.
I have never used Ammonia or had the need to use it.
How did you end up with 3 gallons???
How much powder was there?
One tell tale here would be the green color, which means it has Copper in it, where did the copper come from?
Was this the “quadratic precipitant”?
Did you check that the solution still was acidic? Since it was 3 gallons, was this the full AR or diluted?
Did you have air bubbling or other circulation going in the bucket?
No comment
Nitric substitute only?
Dark to clear may mean false positive or too much oxidizer(Nitric).
You “know” when it tests positive with stannous!
It may be further back in the process.
How much boards did you strip?
I did not see the Copper comment tge first time, sorry for that
No, there were pieces of copper remaining, probably also nickel, solder, silver and other commercial metals. See photo (items #1 and #5
in the photo). These large pieces and other solids were filtered out before adding the urea.
It came with the starter kit
The woman (with a really nice voice) in their video, suggested it. BTW...it did clean up the mud fairly well.
I mixed many different batches of Shor AR and it just accumulated to ~ 3 gallons. Total powder may have been ~ 20 grams (educated guess). I am weighing everthing now. My gold plated parts have copper base metal.
Good question.. I first used their version of SMB (called quadratic precipitant), then I foolishly used a ton of actual SMB in my desperation.
I have sinced learned to settle down.
I just ordered a PH kit, so I do not have that answer yet.
No air bubbling - just occasional stirring outdoors.
This morning, I mixed 50 ml of 31% HCL with 50 ml distilled water and added 10 grams of Shor MX3 (their Nitric acid substitute). Their MX3 does not mix well at 31% HCL. I stirred till dissolved then added exactly 10 grams of the brown powder that was at the bottom of this 5 gallon bucket and heated it. Unlike past mixtures, this time it did NOT fume excessively.
I have been guilty of adding too much Nitric in the past (lol)
I agree - that is why I added the copper tubes to try to cement it out.
I added maybe a kilo of boards and lots of pieces #5 in the photo (maybe 500 grams of these pieces).
The good news is that this is just a small test that I truely screwed up. I will scale it up once I gain more knowledge.
Thank you.
Attachments
Oh man 
it will need quite some time to chew this experience
No worries, we will fix this.
First off, you need to understand basic chemistry what is going on here... No by brand names (even if the woman in ad has nice voice ), but by oxidation states and logic.
Then we can move to actual refining.
First thing is, if using AR, you need to be sure you dissolved ALL metals - because gold is most noble metal from all contained ones - and it will precipitate on any other less noble metal resting in solution.
Second thing is derived from first - due to this fact, pouring some acids on boards is generally a bad idea.
I assume you were after visible gold plating. If you do not see any gold on boards and stuff you fished out of solution, it can be either in liquid or still on the boards - reprecipitated as fine mud.
Forgot the branded unknowns and purchase some HCL and nitric acid. Then we start refining
it will need quite some time to chew this experience No worries, we will fix this.
First off, you need to understand basic chemistry what is going on here... No by brand names (even if the woman in ad has nice voice
), but by oxidation states and logic.Then we can move to actual refining.
First thing is, if using AR, you need to be sure you dissolved ALL metals - because gold is most noble metal from all contained ones - and it will precipitate on any other less noble metal resting in solution.
Second thing is derived from first - due to this fact, pouring some acids on boards is generally a bad idea.
I assume you were after visible gold plating. If you do not see any gold on boards and stuff you fished out of solution, it can be either in liquid or still on the boards - reprecipitated as fine mud.
Forgot the branded unknowns and purchase some HCL and nitric acid. Then we start refining
All of this isn't helping AgandAu get to the gold. I thought there was a photo of a beaker full of relatively clean looking precipitate assumed to be gold on this thread. It doesn't help removing photo's that caused us to think one way only to have the story go the other way. EDIT, sorry that photo was on a sodium metabisulfite thread.
Anyway, you used Shor's pseudo regia and it successfully stripped the boards? Down to the resin board or was there still metal on the boards when you pulled them? From what you said, you did a dissolve of the metal on the boards and the solution was what color? If it was aqua regia on copper clad circuit boards it would have been green, dark green.
The trouble started when you added this mud to more Shor pseudo regia and it dissolved completely? The solution turned what color? You said green, but after what you started with, presuming it was a once refined gold precipitate which was leached in ammonia, it should not have been green. That is still a giant red flag. At this point, did you test with the Shor indicator before adding more urea and the Shor precipitant?
Let's make sure what I've said here is true before we move on because this is becoming a riot of misinterpretation.
Anyway, you used Shor's pseudo regia and it successfully stripped the boards? Down to the resin board or was there still metal on the boards when you pulled them? From what you said, you did a dissolve of the metal on the boards and the solution was what color? If it was aqua regia on copper clad circuit boards it would have been green, dark green.
The red I referred to was when you re-digested the brown mud, that much gold, would turn the acid red. Because it is substantial gold and few other metals. This is gold that indicated positive in solution from a stannous test. (Question, is the test actually labeled stannous chloride test solution or is it Shor magical mystery juice #1). You precipitated a brown mud after using urea using the Shor precipitating agent (actual chemical name unknown). After the metal dropped you filtered and washed it and soaked it in ammonia. That will get any residual silver chloride and copper out. Did the liquid tint a little blue?
The trouble started when you added this mud to more Shor pseudo regia and it dissolved completely? The solution turned what color? You said green, but after what you started with, presuming it was a once refined gold precipitate which was leached in ammonia, it should not have been green. That is still a giant red flag. At this point, did you test with the Shor indicator before adding more urea and the Shor precipitant?
Let's make sure what I've said here is true before we move on because this is becoming a riot of misinterpretation.
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Oh bro thanks for this post as I didn't know how to explain my problem
I burned a couple of ribbons and some cellphone boards too and use hcl and nitric acid but I didn't have enough nitric acid, I probably had about 500ml or less.
After I did that I added some water, and urea. Left it for about 4 hours
Then because I didn't have filter paper I used a cloth and filtered all the hard particles then smb, the next morning got all the muddy stuff under,
The liquid still bluish green tho so I ordered more nitric acid, hcl, urea, smb.
I want to know should I add urea first?
Or should I add more smb?
I didn't have stannous but will have this time so I'm not sure what in there I'm only suspecting there gold because of the کلر
The good thing I didn't use all the boards just a few to see what was going to happen
Thanks
So nobody reads Hokes anymore or search the forum??
The ribbons and the cellphone boards will have less than 1 gram of gold,
likely way less than 0.5g depending on how much boards you processed.
To dissolve that much Gold you need less than 1ml of nitric in HCl.
But since there is a lot of base metals you need way more, but not as much as 500ml.
First of all Urea is for your garden.
Best solution is not to overuse your Nitric, deplete it or use Sulfamic acid.
When going after the Gold directly with AR there is ONE rule, ALL metals needs to be dissolved.
Any base metals left behind will cement out/steal your gold.
Even if it is hidden inside the PCBs it will.
The mud is where the Gold is, at least some of it depending on the previous condition.
The blueish green is to be expected due to the dissolved Copper.
So you should stop here.
Take the mud and boil it in HCl for some time and then water.
What is left behind should be most of the Gold.
Set it aside for later when you have more for a later refining.
What you need to know, is that even though there is golden traces on the boards that is it, there are no Gold inside the boards.
The gold outside the boards may seem like a bit, but it is exceedingly thin so it won't add up to much.
I would guess 0.25g or less per kilo of boards.
As I asked Seny, have you read C. M. Hokes book or tried searching the forum at all???
Hello All,
My sincere thank you for your valued input! I have decided to conclude this thread because:
A) I was a real beginner when I mixed this batch back in May of 2022 (and I had not yet discovered this Forum)
B) I do not have sufficient details/photos/memos/memory of exactly what I did, to provide to you
C) I do not want to waste your time helping me trying to recover the gold in my periodic table of soup. I know there is gold in
there and I will eventually find it - even if I have to FedEx it into the bucket
Accordingly, I have regrouped, searched, read and will document all actions going forward. I also ditched the Shor International Products
and ordered Concentrated Nitric Acid. Thanks again gentlemen.
My sincere thank you for your valued input! I have decided to conclude this thread because:
A) I was a real beginner when I mixed this batch back in May of 2022 (and I had not yet discovered this Forum)
B) I do not have sufficient details/photos/memos/memory of exactly what I did, to provide to you
C) I do not want to waste your time helping me trying to recover the gold in my periodic table of soup. I know there is gold in
there and I will eventually find it - even if I have to FedEx it into the bucket
Accordingly, I have regrouped, searched, read and will document all actions going forward. I also ditched the Shor International Products
and ordered Concentrated Nitric Acid. Thanks again gentlemen.
