Stumped by Stannous...
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Now I'm a bit confused, a precipitate do not test anything in Stannous.
When it is precipitated or cemented it is metallic powder and Stannous only reacts to ionic compounds aka salts.
So please can you elaborate a bit, I really do not understand how.
I am honestly not sure...I have apparently done something quite wrong then because if I take what I thought I had cemented from the copper (as shown in the pic above), put it in the test plate with HCl and then stannous test it I get readings that look exactly like the colors for Pt and Pd. I will try again.
Can you describe in detail how you did it?
I'm expecting that you used air bubbling or strong stirring in the solution before adding the Copper.
It should also preferably be hot, not boiling, but hot.
I placed the salts I had previously obtained by boiling the stock pot down to a crust and put them into HCl, got it to boiling to dissolve them, lowered the heat a bit to stop the boiling but still kept the temperature hot. Then I added an aerator/bubbler (just a basic fish tank style) that sat above the bottom of the beaker but below the copper and let the solution stir for a few minutes before I added the copper. For the copper I used thick gauge wire in a bundle and placed it inside of a pvc pipe with holes drilled into it (similar to what I saw in the article "when in doubt, cement it out"). When I placed that into the HCl solution it immediately started bubbling and spinning around in the beaker. I let it go for about 45 minutes until I noticed the copper starting to dissolve and turn black. I then removed the copper, turned off the heat and let everything in the solution settle for about 4 hours until the solution looked clear/very pale green. Filtered the solution off and then dried the cement at the bottom of the beaker on low heat.
You dissolved the metals in AR i guess?
There is no need to evaporate unless there is Nitric at play.
And it should not be evaporated to a crust, just syrup.
Actually evaporating to a crust may have negative effects, I can't remember why just now.
Add a bit of salt to avoid this.
The cementing part seem OK though, but again no need to evaporate all, then you will get all other dissolved salts too.
Just let it settle and pour off the surplus liquid.
Edit to add:
It is wise to siphon off with pipette or other method of suction to avoid loosing the cement which may be very fine.
Evaporating to a crust was only when I boiled down the stock pot. When I did the cementing with copper, I did not evaporate any of it. Just filtered out the liquid. I am going to try another round with the copper and see what I end up with, but my question is once I have the PGM's cemented, would the best method be to dissolve the cemented value in nitric to remove any possible copper which should leave only the Pt and Pd (from what I've read neither of these should dissolve in the nitric) and then dissolve this into AR and to individually precipitate the Pt and Pd salts?
edited thought:
or maybe doing nitric alone first is a bit overkill as the copper would dissolve anyways if I put all of it straight into AR... just trying to remove everything unwanted as much as possible before attempting to precipitate individually again.
I appreciate you taking the time to help me out. I loved chemistry when I was in school, and it amazes me how much I seem to have forgotten since then.
edited thought:
or maybe doing nitric alone first is a bit overkill as the copper would dissolve anyways if I put all of it straight into AR... just trying to remove everything unwanted as much as possible before attempting to precipitate individually again.
I appreciate you taking the time to help me out. I loved chemistry when I was in school, and it amazes me how much I seem to have forgotten since then.
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A couple of things.
Pd dissolves in Nitric alone, and when Pd and Pt is intermingled, a significant amount of Pt will follow.
Dissolving Cu can be done with Ammonia or Copper Chloride etch.
The issue with the Copper Chloride aka AP etch is that some Pd may be dissolved in that too.
Why are you going to redissolve them in AR again when you already have them as Cement?
Separating them is at best tricky and lengthy if you need complete separation.
What is your plan with them?
Thank you for the info...separating the platinum from palladium, as much as I can anyways, is my plan. Basically, long story short, my husband and I are mechanics and have accumulated around 15 catalytic converters. I've always had an interest in chemistry and have read a lot about people breaking them down into their separate PGM's and wanted to try it; my husband thinks there is no way it'll work. I'm trying to prove him wrong. If I am successful and can send them to a refinery for a few extra bucks, great, if I can't do it then my husband gets to say, "I told you so" and I'm trying to not let that happen ha-ha. I've come this far after many tries and would like to try my best to separate the Pt from Pd as much as I can which is where my plan for redissolving the cement into AR (now that the base metals are out, which was the problem I kept running into prior to all the help I've received on this forum) and reprecipitating the Pt and Pd individually, came from. If I can get them precipitated separately, or as much as I can, I have a pretty good understanding of calcining the salts into sponge. If I can get to that point, I will consider this experiment a great accomplishment.
PS! Take care for your health working with PGM salts.
Catalytic converters should not have base metals, unless they are of the metal honeycomb version.
The powders from cementing might go easily into solution using HCl Peroxide, which will remove the need for evaporating.
If you can get your hands on some DMG(Dimethylglyoxime), it is quite selective for Pd.
There will be drag down of Pt but not too bad, and it can be repeated so the situation improves.
How about Rhodium in the Cats?
They are all the honeycomb type. I had not thought of using HCl Peroxide, that might be a good way for me to go about it. I have tried DMG when I first started this project, but I think I had messed up several other steps leading me to believe I wasn't having luck with the DMG. I have read much more about it since then and I can't see the DMG having been the problem. I think I will try the HCl Peroxide solution and then try again using the DMG to precipitate the Pd. The rhodium is still a work in progress but is definitely on my list of things to figure out. I can't seem to find nearly as much definite information for the rhodium and so far, the times I've attempted to do anything with it, I've felt like I'm running in circles with no real progress made.
Safety/health has been a priority for me when doing this experimenting. I've built a fume hood and scrubber in addition to always wearing a respirator, gloves, safety googles and keeping everything clean and organized! I know working with these materials isn't something to take lightly!
Safety/health has been a priority for me when doing this experimenting. I've built a fume hood and scrubber in addition to always wearing a respirator, gloves, safety googles and keeping everything clean and organized! I know working with these materials isn't something to take lightly!
Pt and Pd is like another continent comparing to Gold and Silver. Rhodium is then the other planet.
A lot less information and a lot harder to do.
It is there though.
When doing ceramic honeycombs, just cement on Zinc. There should be no base metals to worry about.
But to get the most Rhodium one might need concentrated Sulphuric acid.
Orvi has a good thread where he discusses separation of Pd and Rh and his struggle to get it done to a sufficient purity so he could get paid for it.
I just use full strength HCl and add Peroxide as needed. My Peroxide was old 30%, so I guess it was around 15-20 for real.
So I use Peroxide as I use Nitric.
ok, thank you very much!! I believe Orvi sent me the post you are referring to in one of his responses to me earlier in this post! I greatly appreciate all of your advice today and throughout this posting! It has helped me a lot!
Platinum precipitation seems to have been a success! Palladium is proving to be much more difficult...I don't currently have access to DMG so I am attempting to precipitate using sodium chlorate and chlorine granules (not at the same time, I've tried with each individually) but I continue to only precipitate a yellow crystal looking salt (last image, other images are the platinum) that isn't stannous testing positive for Pd, or anything else.
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I believe something is off somehow.
These images are a bit puzzling, can you describe each one a little bit.
The spot plate has a brown precipitate, can you try it on paper or cotton bud in stead?
The gray one, what is that?
I'll try posting a pic with it on cotton or a paper filter, but usually I have a problem with it running everywhere and it's hard to see. the bit of precipitate is the piece of salt not fully dissolved in hcl when I added stannous. the gray is what the orange precipitated salt in the pics turned into upon heating. upon further heating this was my end result...
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the yellow salt was my attempt at precipitating the pd but didn't work, that salt is what I keep ending up with but it doesn't test positive for pd or anything else and i can't get the red palladium salt to precipitate. the solution to my best understanding is testing positive for pd. I'll post pics of that with the retake of my pt test on a filter paper in a bit.
