# Platinum recovery from catalyst, help needed.



## wazaiken (Jun 21, 2011)

Hi All,

First post so please be gentle.

Im extremely new to this. I have been gathering a humble collection of gold and silver bars which has given me the bug and have just started tinkering with recovering some silver and gold from scrap. 

I now have some platinum catalyst(PtAl2O3) surplus from commissioning a combustor on a small hydrotreating plant. Which I believe is platinum on an alumina structure(?). They are beads approx 5mm in diameter and I have attached a picture. I would love to be able to recover the platinum and estimate this to be around 0.5% of the total weight(I have a few hundred kg's of beads). My only question is, how?

Ive been reading plenty on this site for the last day or so but havent really found to much to help me on this. Its quite possible ive missed something so im happy to just be pointed in the right direction if thats the case. I have excellent access to chemicals and lab supplies as well as reasonable access to equipment. Its no problem for a small scale solution I can just poke away at over several months.

Love the site and look forward to spending more time here.

Waz


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## skippy (Jun 21, 2011)

I would use either hydrochloric acid and H2O2 or the SSN leach (a saturated salt solution with nitric acid added). There's also HCl + sodium hypochlorite. 
The catalyst looks pretty clean to me so I'd say you don't need to do anything but leach it. IE no roasting off carbon is needed.
Start small, like in test tubes or small flask scale and just try to see what leach conditions work best to extract the values from the material. Learn how to use stannous chloride. It's key. 
While it is leaching give the container a stir every once in a while, and do something to keep the temperature of your leach a little elevated, maybe about 50C. The 
HCl+H2O2 will work pretty well at room temperature too though. You're in a good position because you only have one precious metal in your catalyst.


Read as much as you can here especially on catalyst processing, and you can't go wrong with Lazersteve's PGM video. Steve's video is a great introduction to this topic.
I look forward to hearing how this goes for you.


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## wazaiken (Jun 21, 2011)

Thanks Skippy,
Ill read up and have a little play around with some different leach methods. I wasnt sure if i should crush them down first. Actually If im able to keep the beads in tact ill be able to sell them off as inert catalyst supports so ill be really wringing the $$$ from them.


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## Harold_V (Jun 22, 2011)

One of the best things I can do to help you with this project is to advise you to read Hoke's book. It will explain, in detail, how you can extract the values---although it won't directly address the beads you have. What it does address is the basics of refining and testing, each of which should be understood before you take the plunge to extract the values. If you fail to heed this advice, you're going to stumble along blindly, with no end to questions, and most likely, less than acceptable results. 

You can download a copy of Hoke's book by looking at the sig line of many of the readers---one of which that comes to mind is Palladium. Do a search for his posts, then read his sig line. Please retrieve a copy of the book and start reading. Read until it makes sense. 

Welcome to the forum. 

Harold


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## wazaiken (Jun 22, 2011)

I had noticed the recurring theme of, "read Hoke's book", across the site. However, I cant stand to read something that long on a PC and printing it out on A4 paper just isnt the same so I ordered a hardcover copy(hard to find). I got a lot from the sections I did read online so I cant wait for it to arrive.


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## Harold_V (Jun 23, 2011)

I congratulate your wisdom. 
What many readers fail to understand is that Hoke's book isn't like any other. It does not discuss theory---it teaches you, hands on, how to deal with valued wastes. Once you understand what she teaches, you'll be able to address almost anything you can encounter---because you'll have a grip on the basics. Further more, while there may be some processes that are better, what she teaches will yield exceptional results---and it's all done in such a way that even I could understand what she was teaching. 

Good luck!

Harold


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## amon13 (Sep 10, 2011)

Hello i have the same material (balls) like this in the picture i break 1 ball to see what is itinside and i see somthing like graphie inside and other material like metal . So i try to see what happened if i put some of this balls in nitric to see if some base metals presents but nothings happen -not colored change in the solution .After this i put those balls in "AR" and test with stanos chloride - no results for gold.
So no base metals no gold - what i have to try to see any values
I see some posts that i must try hcl an H20 but how exactly - proportion pleace explain step by step i have 4 tons from this material..........


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## Palladium (Sep 10, 2011)

How long did you leave the balls in ar and did you add plenty of heat?
Did you neutralize the excess nitric before you tested? 
Free nitric will obscure the test.


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## Joeforbes (Sep 10, 2011)

amon13 said:


> Hello i have the same material (balls) like this in the picture i break 1 ball to see what is itinside and i see somthing like graphie inside and other material like metal . So i try to see what happened if i put some of this balls in nitric to see if some base metals presents but nothings happen -not colored change in the solution .After this i put those balls in "AR" and test with stanos chloride - no results for gold.
> So no base metals no gold - what i have to try to see any values
> I see some posts that i must try hcl an H20 but how exactly - proportion pleace explain step by step i have 4 tons from this material..........



I doubt very much you're going to have catalyst material that contains gold. 

The process I would use to refine these is a dangerous one. So I'll suggest instead putting the material in HCl + H202 (3% over the counter concentration) then heat them to a boil. Add small amounts of bleach every half hour or so for several hours. 

That will remove Pd, Pt, and Rh (not very effectively with the Rh but enough to test for it's presence) if they are present.


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## amon13 (Sep 11, 2011)

Palladium said:


> How long did you leave the balls in ar and did you add plenty of heat?
> Did you neutralize the excess nitric before you tested?
> Free nitric will obscure the test.


 Hello Palladium and thank you for the response
So i put the material in AR for 1 hour(maybe is a litle time for the full reaction,but i see no reaction at all)
but you have very good point to ask me for the excess nitric (because in the first step when i put the material in nitric to disolve the base metals i dont see reaction - so in the Aqua Regia the nitric dont react with the material -so i have a excess nitric.
I dont add urea to neutralize the excess nitric in Ar 
Maybe i must do another test.
if You have any ideas pleace post
thank you again


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## amon13 (Sep 11, 2011)

Joeforbes said:


> amon13 said:
> 
> 
> > Hello i have the same material (balls) like this in the picture i break 1 ball to see what is itinside and i see somthing like graphie inside and other material like metal . So i try to see what happened if i put some of this balls in nitric to see if some base metals presents but nothings happen -not colored change in the solution .After this i put those balls in "AR" and test with stanos chloride - no results for gold.
> ...



Hello Joeforbes thank you for yuor response
sorry for my english - are you mean 1part Hcl+1part H202 and putting the material(the balls must be equal 3% from the solution).
Did you mean as i boil this to add a bleach or after boiling \
thank you again


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## Joeforbes (Sep 11, 2011)

amon13 said:


> Joeforbes said:
> 
> 
> > amon13 said:
> ...



Аз използвам 1 L H202 и 200 мл солна киселина на килограм катализатор.Добавя се вода, за да обемът на решение за покриване на материала.След това да доведе до възпаление.Тъй като това е изваряване, се добавят 20 мл белина някога половин час в продължение на шест часа.

My Bulgarian could use some work I'm sure..


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## Palladium (Sep 11, 2011)

Joeforbes said:


> amon13 said:
> 
> 
> > Hello i have the same material (balls) like this in the picture i break 1 ball to see what is itinside and i see somthing like graphie inside and other material like metal . So i try to see what happened if i put some of this balls in nitric to see if some base metals presents but nothings happen -not colored change in the solution .After this i put those balls in "AR" and test with stanos chloride - no results for gold.
> ...



Have you done this process? The reason i ask is with all that heat you’re not going to keep the H2O2 or the cl in solution very long. Hotter solutions mean less dissolved gases and quicker off gassing. 
Nitric acid is harder to expell at elevated temps.


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## Joeforbes (Sep 11, 2011)

Palladium said:


> Joeforbes said:
> 
> 
> > amon13 said:
> ...



Quite a few times, as a matter of fact. I got the idea from posts on this forum even.


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## amon13 (Sep 14, 2011)

Joeforbes said:


> Palladium said:
> 
> 
> > Joeforbes said:
> ...


 
Pleace help me wit this process step by step


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## Joeforbes (Sep 14, 2011)

amon13 said:


> Pleace help me wit this process istep by step



*Slaps hand to forehead*


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## amon13 (Sep 17, 2011)

Joeforbes said:


> amon13 said:
> 
> 
> > Hello i have the same material (balls) like this in the picture i break 1 ball to see what is itinside and i see somthing like graphie inside and other material like metal . So i try to see what happened if i put some of this balls in nitric to see if some base metals presents but nothings happen -not colored change in the solution .After this i put those balls in "AR" and test with stanos chloride - no results for gold.
> ...



Ok im finish with the H2o=Hcl+cl boiling as you told the solution is red-brown 
but how to test for platinum i try with stanuos but not color change any ideas?


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## samuel-a (Sep 17, 2011)

amon13 said:


> Ok im finish with the H2o=Hcl+cl boiling as you told the solution is red-brown
> but how to test for platinum i try with stanuos but not color change any ideas?



Take a 50-100ml sample, filter it and put a slab of Zinc or Aluminum and look for black fluffy precipitate.

Black precipitate will indicate PGM's content. Dry this powder, add dilute Nitric acid, whetever solid left is most likely Pt/Rh.
You solution may still be oxidizing and foul your SnCl2 test.


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## lazersteve (Sep 17, 2011)

samuel-a said:


> Take a 50-100ml sample, filter it and put a slab of Zinc or Aluminum and look for black fluffy precipitate.
> 
> Black precipitate will indicate PGM's content. Dry this powder, add dilute Nitric acid, whetever solid left is most likely Pt/Rh.



There is a distinct possibilty of other non-precious metals being in the black precipitate. Converters can have nickle, iron, and other base metals present as contaminates.

There is also the possibilty of Cab-O-Sil contamination in the powder if using powdered zinc. This contaminate will remain even after nitric, AR, or many other acid treatments.

Steve


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## samuel-a (Sep 17, 2011)

He can easly test the nitric for Pd with SnCl2 or DMG, even if there are base metal such as nickel or iron.



lazersteve said:


> *This contaminate will remain even after* nitric, *AR*, or many other acid treatments



The fact that a substance does not dissolve in AR is also an indicatior.
Anyway, the AR could be also tested easly for Pt.

If any more solids remains he could boil in H2SO4 or fuse with bisulfiate and test for Rh.




lazersteve said:


> There is also the possibilty of Cab-O-Sil contamination in the powder if using powdered zinc.



I find it much more convenient to work with turning or solid slabs then powder...


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## skippy (Sep 17, 2011)

lazersteve said:


> There is a distinct possibilty of other non-precious metals being in the black precipitate. Converters can have nickle, iron, and other base metals present as contaminates.
> 
> There is also the possibilty of Cab-O-Sil contamination in the powder if using powdered zinc. This contaminate will remain even after nitric, AR, or many other acid treatments.
> 
> Steve



Steve, if there is substantial black precipitate it's a pretty good sign there are/were values in the solution though, no?
Another possibility is to put a piece of copper wire in the solution and see if a black coating or crust willform. The black crust will be a noble metal.


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## skippy (Sep 17, 2011)

Amon,

How are you preparing your stannous chloride? Have you had previous success testing your stannous solution on any other dissolved metals? You may need to establish if your stannous chloride is working by testing it on a solution known to contain dissolved precious metals. Learning to use stannous chloride will be important at the leaching stage, and also later when you need to check if your recovery from your solutions is complete.


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## Joeforbes (Sep 18, 2011)

lazersteve said:


> samuel-a said:
> 
> 
> > Take a 50-100ml sample, filter it and put a slab of Zinc or Aluminum and look for black fluffy precipitate.
> ...



I'm not sure if it is vehicle catalyst material. He said it was like the material in the original post of this thread. If it is industrial catalyst, who knows what it could be. Thorium oxide catalyst beads are used in a number of pharmaceutical productions.. Lets hope it's not that.


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## skippy (Sep 18, 2011)

Going back to something Amon said earlier, he said he didn't add urea to eliminate excess nitric acid. But does nitric acid get reduced by urea in low to medium cconcentrations? I thought urea only worked on the nitric oxide, which I guess would help in reducing the nitric by preventing recycling from NO->NO2. Or can the urea eliminate nitric by reacting with nitrosyl chloride and chlorine until the nitric acid is gone? I hope this hasn't been covered before.

The reason I ask is I tried extracting some catalyst with SSN, but SSN uses a large excess of nitric acid (or in my variation HCL+NaNO3) in comparison to the amount of metal I am dissolving, so it would be nice if urea would kill the action that the nitrate ions are producing in this acidic solution. The palladium isn't cementing very well due to this excess oxidant. I would use less nitrate, but I was concerned that a lower concentration wouldn't be effective on platinum and rhodium.

I'll try it myself when I get my hands on some urea, but I thought I would ask for the sake of knowledge and understanding.


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## Joeforbes (Sep 18, 2011)

The urea works by reacting with the nitric acid to form urea nitrate, a high explosive commonly used in I.E.D's.

http://en.wikipedia.org/wiki/Urea_nitrate

Instead of using urea, you should condense the solution. You need to convert the Pt and Pd nitrates into chlorides in order to keep them from co-precipitating when adding ammonium chloride, which is done by condensing the solution and adding small amounts of HCl until no fumes are expelled. The precipitations are also more effective in concentrated solutions than dilute ones.

Also, if you are using excess nitric acid, then you are only throwing money away. I've stopped using nitric acid to process initial source material of any kind, there are work arounds that are way cheaper. A penny saved, right?


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## skippy (Sep 18, 2011)

Joee, unfortunately the solution can't be boiled down effectively because it is saturated with sodium chloride. I'll have to use a large excess of zinc to kill the nitric, or reduce the amount of nitrate and accept that the dissolving action might not be as strong. Generating Cl2 from HCl in situ is probably a better way to go, but I wanted to see how a long hot (70C 3 days) SSN leach would fare against the rhodium, and I'll see how HCL-Cl2 does later.


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## skippy (Sep 18, 2011)

The urea nitrate isn't dangerous while in solution is it? It's soluble, and I don't think it would ever come out of solution, as my SSN leach is mixed with the liquids from rinsing the ceramic and is now pretty dilute.


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## butcher (Sep 18, 2011)

http://cameochemicals.noaa.gov/chemical/12966,
dry or possibly even wet with strong heat.


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## Joeforbes (Sep 18, 2011)

skippy said:


> The urea nitrate isn't dangerous while in solution is it? It's soluble, and I don't think it would ever come out of solution, as my SSN leach is mixed with the liquids from rinsing the ceramic and is now pretty dilute.



Probably not. I've heard of it exploding, but I haven't seen any posts on this forum about anyone having it happen to them. I would be more concerned about storing it in waste solution than having problems with it while neutralizing.

In the link Butcher posted, note the line that says "MAY EXPLODE AND THROW FRAGMENTS 1600 meters (1 MILE) OR MORE IF FIRE REACHES CARGO. (ERG, 2008)" 

Zinc nitrate is also dangerous - and that I know first hand. I have had beakers burp fire when trying to drop AR solutions with it when I first started refining. 

Use iron. If you plan to purify the metals again after precipitating them, you could even use steal wool to cut down on the expense. The only problem with it is the carbon it leaves behind can really clog a filter paper.


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## butcher (Sep 18, 2011)

http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=4059&view=print

I do not think you would have trouble with urea in solution exploding, but then I really do not know, I do not use urea for several reasons, I believe I read it can give problems with the platinum group metals.


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## amon13 (Sep 21, 2011)

So unfortunately i don't have any values i try to precipitate with alumina , starting bubbling but nothing happen finally the pice of alumina gone, no precipitate


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## amon13 (Sep 21, 2011)

Joeforbes said:


> lazersteve said:
> 
> 
> > samuel-a said:
> ...



He said it was like the material in the original post 
YES THE SAME MATERIAL


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## skippy (Sep 21, 2011)

amon13 said:


> So unfortunately i don't have any values i try to precipitate with alumina , starting bubbling but nothing happen finally the pice of alumina gone, no precipitate



Is there nitric acid in your solution still? That would stop metals from cementing
You may not have added enough aluminum either (zinc is a better choice).


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## Palladium (Sep 21, 2011)

amon13 said:


> So unfortunately i don't have any values i try to precipitate with alumina , starting bubbling but nothing happen finally the pice of alumina gone, no precipitate



If you have any free acid the alum will dissolve until the acid is used up. Then it will precipitate the metals from solution. 

Use copper !!!!!

Looks like skippy beat me to it. :lol:


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## bubba (Oct 3, 2011)

All I can say boys, is give your best shot, use your best sure-fire wet chemical process. But before you start, set aside a portion of un-processed material ( the heads) and then take your processed catalyst when you are done (the tails) and have both assayed. I must stress at this point how crucial it is to utilize an assayer like Inspectorate or Ledoux, who has extensive PGM assaying experience.If someone says they can do a three element PGM assay for less than $500.00 be very suspicious. Compare the two assays, how did you do? pay close attention to the Rh, what did you pull? 50%-60% ? maybe you did if you were lucky.
This is the reason why you are wasting your time playing with catalytic converters using a wet chemical process. Its not that I am a pessimist, I have been in this business for 15 years and I am laying out the facts. If you can't recover 96%-99% of the Rh like a plasma arc furnace can, then how much Pt and Pd you recover is totally irrelevant.


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## skippy (Oct 4, 2011)

Bubba, this thread is not about automobile catalyst, so concerns about rhodium recovery may be irrelevant.


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## Lou (Oct 4, 2011)

Yes, for normal Pt over alumina or carbon, you can get close to quantitative recovery, but the loading is usually 50-100X higher.


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## bubba (Oct 8, 2011)

skippy said:


> Bubba, this thread is not about automobile catalyst, so concerns about rhodium recovery may be irrelevant.



You think I don't know what this thread is about? It's called cracker catalyst in case you wanted to know, and VERY difficult to get any type of steady flow of this material unless you can offer the customer a pool account for their metal. You are telling this guy there is only one element, why?, because you saw the assay? contrary to what you might read in a book or on the internet, cracker material can be just as application specific as auto catalyst. I have seen 10,000 ppm Pd. from the cosmetics industry, 3,500 ppm Pt. with 600 ppm Rh. from petroleum refineries. Its a broad range, and the oil companies in particular figured this out years ago, that why the will only sell their cracker on a toll basis.


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## skippy (Oct 8, 2011)

Bubba, mixed auto catalyst is almost certain to contain Rh, whereas one batch of industrial catalyst may easily have none. In which case, as Lou said, someone could go and recover nearly all platinum that may be present.
I didn't presume it contained or didn't contain anything, I only suggested that rhodium may be a non issue. 
Your point was good though, and it's definitely something for the owner to strongly consider, having it processed with plasma professionally.


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