Pgm extraction magnetic SS

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Reverse AR will probably work depending on what PGMs you have but you do need a fume hood and be able to neutralize the excess nitric.
This takes some knowledge and practice it is also producing highly toxic salts, so read and protect yourself, so if you have no experience try small batches to perfect the technique before doing bigger batches.
 
What do you mean by reverse Ar? I have extracted pgm off honey comb w/ hcl & peroxide by heating the hcl solution for 3 hours . I have a 48" paint booth fan hooked to my fume hood in my shop.
I was able to precipatate Rh&PD along w Ag using Sodium Chlorate . I am well aware of platinosis & muster gas dangers this produced.
I have no experience with nitric.
I assume your saying to dissolve all the SS with nitric , decant the solution and filter remaining powder which should be Pgm & bit of alumina oxide .
 
Nitric will passivate the SS and then addition of HCl will make weak AR, which in turn dissolves the other metals.
If you have a metal honeycomb, it will easily dissolve in HCl.
But this will consume a substantial amount of HCl and time,
if you get it cheap and easy, this is still an easy way to go.
You will then be left with a powder containg the PGMs and it will be easy to go from there.
Just test the "spent" HCl (because it may have dissolved some PdO) before diverting it to the waste process.
 
Ok I got you so test with stannous & if it shows no pgm in solution , neutralize and dispose of solution at haz waste drop off .
Can I dillute the hcl solution ?
 
You mean dilute for dissolving?
I have done this once and I diluted it some, but din't use heat.
It will have been faster if heated, and it will most likely dissolve more metal pr given volume of acid if diluted.
 
I relly don't know, I think I used 8l for one, acid wise that was probably too much, since it was done cold.
I covered the matrix in diluted HCl and when there was no more visible reaction I added more acid.
When the volume got too high for the bucket, I emptied some of the acid (to the waste stream) and continued.
 
There are two different methods mentioned in this thread.
- Nickvc talks about reverse AR. Nitric acid with small additions of HCl
- Yggdrasil talks about dissolving the stainless steel with HCl.

Just pointing it out to those reading this thread and not knowing the difference so they doesn't get confused.

... carry on!

Göran
 
Will I be left with alumina and pgm since the pgm is on a alumina washcoat?

I was told by the rep after I gave him serial # that there's 0.7 of pgm per total weight .
Total weight is 26,880 gram that's including the frame . I removed the frame and that weighs about 800 grams .
I'm hoping I should have about 180 grams of pgm.

Another thing I noticed is while removing this substrate ( while wearing respirator) slot of fine brown powder gather at bottom of plastic bin .

Would it be possible to agitate the sheets against each other and collect the powder hopefully containg the pgm , or should I test a small amount with stannous before I go hung up with the hcl .
 
As Gøran say, these are different approaches, dissolve the SS which creates a substantial amount of waste or use reverese AR and passivate the ss with nitric.
The positive with the first method is that you are left with the washcoat and the pgms in a concentrate and it should be complete and easy to process further, downside is the amount of waste acid.
The positive with the reverse AR is it creates little waste, only what is needed to cover the substrate.
On the negative side it demands a lot of nitric (It can be used for many converters though), it may not dissolve all the PGMs and if it contains Rhodium it may need a additional treatment in hot concentrated Sulfuric acid.
And in the end you will have a lot of liquid to denox.

Mechanical "scrubbing" may or may not remove the washcoat, but I doubt it can be done to any degree of completeness.

I can't quite follow your maths, something are off, are you talking about percentage?
 
Well I was told by rep it contains a lil bit less than 1% of total weight.
I asked him if it was half of 1% . He said " a little more split the difference"
So I'm assuming he meant .7% of total weight which was 60lbs or 26,880 grams . 10% of that would be 2,680 gram and 1% of that is 268grams.
Half of that is 134 grams so Im hoping around 180 grams.
 
What kind of cats are these?
Industrial I guess.
I have only leeched an automotive cat.
This could lend itself nicley for reverse AR, at least as long as they are flat.
It does also have a possibility for mechanically removing the washcoat by different means.
Scraping, grinding or other suitable methods.

Personally I would choose one of the methods that do not dissolve the PGMs

Just a small precaution. In the meaning BIG
The salts of PGMs are quite toxic and should be avoided if possible.
 
Yeah I read on here when I first joined about a member who ended up passing from platinosis.
I use a respirator and gloves and avoid contact with it as best I can .
Does anyone know if it's more toxic while in solution or salt or is it same.
I did notice alot of powder when the plates where rubbed against each other I don't like idea of physically doing it ,cuz a ripped glove or mishap but I don't like idea of a ton of liquid to the waste stream either.
The rep told me I should get about $4,000 from a refiner called Colt . I live in California and am wary about shipping and also hate to turn down the challenge and giving away $6k or more off dollars .
 
None of the Platinum group metals are dangerous in metal form.
I guess that in the cathalytic surface they are just that, so that should be safe.
But it may be so fine that it can be spread around causing losses.
The process thay have been used for may also have left residues that may or may not be harmful
 
I made the leap of faith, took a strip to xrf today after I got ahold of jeweler. They were bored so we met at his store and xrf showed 5% palladium 1% Au1%platinum.
So I started dissolving.

https://photos.app.goo.gl/ibNz4ECtGuSgjEHP8
 
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