# Pgm extraction magnetic SS



## Sorrycantseeme (Mar 18, 2020)

I am looking for best way to extract .5 l% of 60lbs 
Which is roughly 120 grams.


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## Lino1406 (Mar 18, 2020)

Act the same way as non-magnetic


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## Sorrycantseeme (Mar 22, 2020)

I'm not trying to put the s.s. into solution.


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## nickvc (Mar 22, 2020)

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.


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## Sorrycantseeme (Mar 22, 2020)

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 .


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## Yggdrasil (Mar 22, 2020)

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.


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## Sorrycantseeme (Mar 22, 2020)

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 ?


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## Yggdrasil (Mar 22, 2020)

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.


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## Sorrycantseeme (Mar 24, 2020)

i have 60lbs to put into solution . Is there any idea how much hcl i might need.


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## Yggdrasil (Mar 24, 2020)

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.


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## g_axelsson (Mar 24, 2020)

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


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## Sorrycantseeme (Mar 27, 2020)

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 .


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## Yggdrasil (Mar 27, 2020)

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?


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## Sorrycantseeme (Mar 27, 2020)

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.


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## Sorrycantseeme (Mar 27, 2020)

Here's a better look
https://photos.app.goo.gl/GiaDugZKRPmnNGex7


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## Yggdrasil (Mar 27, 2020)

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.


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## Sorrycantseeme (Mar 27, 2020)

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 .


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## Yggdrasil (Mar 28, 2020)

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


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## Sorrycantseeme (Mar 30, 2020)

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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## Sorrycantseeme (Mar 31, 2020)

Any idea how much hcl 31% strength to dissolve 60lbs of magnetic SS?


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## FrugalRefiner (Mar 31, 2020)

You already asked this question in this thread, so I've merged your new thread into this one. Don't keep creating new threads on the same subject. It just clutters up the forum and makes it more confusing to find information.

Dave


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## Sorrycantseeme (Apr 1, 2020)

So I have used 8 gallons so far of hcl 31% mixed with 16 gallons of water . I have 20 gallons of hcl waste that I disposed of to empty fertilizer containers .
I just put 2 more gallons of hcl and 4 gallons of water . I had 30lbs on bottom row and 30lbs of SS sitting on top . It appears I have digested about 40% of SS . Maybe a little less, I tried weighing 5 gallon bucket of waste stream I was hoping to see it weigh much more than 5 gallon bucket of water but it showed only about 3 lbs heavier at 43lbs.


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## g_axelsson (Apr 1, 2020)

To get an idea about what to expect I usually run a small experiment. A beaker or even a test tube. That way I can gain information about how much acid I need, if I need to heat it or not and if there is any flaws in my plan.

For example, taking a beaker with a known amount of acid and adding metal until it stops reacting. If I just keep track of the numbers it's an easy thing to calculate how much acid I need. And if I do this cold, I can heat the beaker to see how much difference heating will make, maybe the acid isn't used up, only working too slow to be noticed without heating.

Göran


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## Sorrycantseeme (Apr 1, 2020)

Damn I thought about that after I started , as long as I keep the waste stream my values should be in there in the form of powder correct


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## sena (Apr 1, 2020)

These ceramic over Ss sheet , hammer mill to 1 inch screen , will liberate the ceramic and steel 
Give a try.


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## Sorrycantseeme (Apr 1, 2020)

Is there any way to do that with the position I'm in now . It's chewed through the majority of material . S.s coating has been digested and is now starting to float on top .
Nobody has a clue on how much or approx how much 31% hcl can hold per gallon ? 
I'd assume someone with years of experience would have a ballpark idea like 1 gallon can hold 1 lb in solution etc.


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## nickvc (Apr 2, 2020)

There is probably no real definitive answer as there are a fair few variations of the alloy, you could have found the answer yourself had you just taken a kilo and tried to dissolve it all and noted how much acid you needed.
The only concern should be is it cost effective to process this material in this way, I would have thought yes if your percentage of PGMs is as you quoted.


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## Yggdrasil (Apr 2, 2020)

As I stated in the beginning, I have done this once with an autocatalyst.
I used appr 8 liters/2 gallons to dissolve between 3-4 pounds of SS.
This was done cold and was on the rich side of the acid, could probably done more with heat.
This may apply to your situation as well.


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## Sorrycantseeme (Apr 2, 2020)

Yeah I rushed into it. 
I have a few more questions . 
The hcl has done a good job of removing 80% of SS surface area , is the shiny layer majority of pgms? 
More important question is will I be left with the alumina and pgms at bottom of container ?


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## Yggdrasil (Apr 2, 2020)

When the SS is completely leached off, you will be left with a mix of washcoat ceramics and PGMs.
In my case that was a relatively coarse powder like sand.


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## Sorrycantseeme (Apr 2, 2020)

Ok so I'm going to have to put the metal in solution. I have done it before and precipitated with sodium chlorate but didn't realize till a couple days ago I'd have to do it again unless ANY1 has any tips or tricks.


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## Yggdrasil (Apr 2, 2020)

Eventually you may have to, but then you have to put all the metal into solution, 
unless you use reverse AR.


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## Sorrycantseeme (Apr 2, 2020)

So I spread my initial container into 2 other container just the metal . I wanted to look at the powder on the bottom and put some hcl on it. 
I took a sample and put it in a small container and hit it with hcl and the video link is below . 
https://photos.app.goo.gl/6y3BVR2h1ewvExfg9

Why won't the little metallic pieces in the sample dissolve? 
Why is the powder so black it will not react with the hcl ?


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## Lou (Apr 2, 2020)

You really shouldn't be doing this over the ground. The foil corrugate is iron chromium alloy and the chromium, even though it is exclusively Cr(III), is not good to get in soil.

When your acid stops dissolving the corrugate and hydrogen gas production ceases, you are left with a mixture of alumina and the PGM component. This material is very rich in PGM but must be further processed before melting.


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## Sorrycantseeme (Apr 2, 2020)

I really appreciate the time & advice I am given by experts. If anything hits the ground I cringe cuz I picture pgm loss , now that I'm aware of environmental issues I really will do my best to make sure there's no accidents , I would of tarped the work area if I would have known but I rushed into this and realize I wasn't prepared. 
That being said I can't Thank every 1 enough for the time and advice.
Can anyone expand on further processing , I am familiar with hcl/ lh2o2 recovery method .
Please any advice on how to proceed based on the experts advice.


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## Sorrycantseeme (Apr 2, 2020)

What further processing is needed . I have added hcl to the black powder & even heated the hcl with no reaction . 
Do I have to now put the pgm into solution via hcl/h2o2 for 3 hours?


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## Yggdrasil (Apr 3, 2020)

The powders left behind when HCl has done its job, is what you want.
Powder composition dictates the best approach from here.
One can send it to specialists for final processing or do it yourself, but be ware of the toxicity of the salts.

I'm not too fond of these boil for two or three hour, mix 1-4 solutions, you select a process to dissolve what you have, which in return decides how to proceed.
Then you run it, until it has done what it should or can't dissolve anymore, always gentle with the oxidizers.

For instance Pd dissolves in nitric, then you go for it until there is no more reaction.
Later you may go for AR, HCl-H2O2, HCl-Bleach or similar to get the Pt or Rh that may be there.
If one suspects Rh a final processing with strong hot Sulfuric and NaCl may be needed.

Separation and refining these metals is outside the scope of most of us, but they can be cemented out from solution with Zinc or Copper, leaving you with pure-ish metal.


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## Sorrycantseeme (Apr 3, 2020)

The majority of it is
PD at .05
PT. .01 
AU .01 
The XRF at a local jewelry store was kindto help me get this data .

My next question is my next move should be ?
Digest in Hcl fully
1Decant to waste stream
Cover cons in hcl 
Wash with H20 
Obtain Nitric and cement the metal out of solution 
Then cupel . I really need to get this to metal form


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## anachronism (Apr 3, 2020)

Sorrycantseeme said:


> The majority of it is
> PD at .05
> PT. .01
> AU .01
> ...



I'm getting confused now. This is the third set (at least) of figures you have used. Let's take Pd. We've gone from 0.5% to 0.7% 5% on an XRF, and now 0.05. Now, which one are you working on because I'm totally lost.


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## Yggdrasil (Apr 3, 2020)

Sorrycantseeme said:


> *I'm not going to comment on numbers*
> My next question is my next move should be ?
> Digest in Hcl fully *Have you dissolved all base metals now?*
> 1Decant to waste stream
> ...



See comments in color


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## kurtak (Apr 3, 2020)

Yggdrasil said:


> The powders left behind when HCl has done its job, is what you want.



Generally speaking HCl by it's self will not dissolve Pd - As in a "solid" piece of Pd

However - VERY finely divided Pd - which is the case of the Pd in the wash coat of CATs - HCl "alone" can & will in fact dissolve Pd

You can read about it in my second post, third paragraph of this thread

:arrow: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=51&t=20573

That did not hold true with all CATs - but it was MOST certainly true with some CATs - The Pd would go into solution "instantly" & I do mean "as soon" as the HCl was poured into the vessel holding the CAT combs

This happened with Cats that where HIGH in Pd & LOW in Pt/Rh - on the other hand CATs that where HIGH in Pt/Rh this did not happen with

The point being --- being as how this CAT is on SS - it is entirely possible that HCl could/may/will put some of the finely divided Pd in the wash coat into solution - but until the SS is dissolved the SS will cause the Pd to cement out while dissolving the SS - then (maybe or not) once all the SS is dissolved - & if there is "free" HCl the finely divided cemented Pd could (maybe) go into solution - The HCl does not need to be hot for this to happen 

Edit to add; - I bring this up in part because according to the XRF read out - the Pd is the "high" PGM in this CAT 

Kurt


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## anachronism (Apr 3, 2020)

I agree that it's defintely to do with other metals being present Kurt.

I boiled a lot of finely divided Pd in HCl for hours last night. It was not in the presence of any other PGMs and the liquor tested clear of any Pd afterwards.


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## Yggdrasil (Apr 3, 2020)

Ok, I believed that that had to do with autocatalysts and the high heat they had been subjected to.
High heat could create PdO and that would dissolve in HCl.
This is an industrial catalyst on large sheets.
Will that be an issue here as well?
Anyway what he wants is what is left from the HCl leach, 
he was told to test the base metal leach from start of the thread and it showed barren, at least according to the OP.
I have been writing in respect to that in the rest of this thread.


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## Sorrycantseeme (Apr 3, 2020)

Not 5% but half of 1%. Which is .05% of 60 lbs is PD .
.01 is PT 
.01 AU

I posted a video earlier and i poured 31% hcl in powder and nothing dissolved


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## FrugalRefiner (Apr 3, 2020)

Sorrycantseeme said:


> Not 5% but half of 1%. Which is .05% of 60 lbs is PD .



Half of one percent is 0.5%, not .05%

Dave


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## Sorrycantseeme (Apr 3, 2020)

Thats what i meant .5%


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## Lou (Apr 3, 2020)

PdO is actually very insoluble in all but a few things.

Finely divided Pd dissolving (in HCl) is usually more due to dissolved oxygen in the HCl making Cl2.


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## snoman701 (Apr 3, 2020)

Lou said:


> PdO is actually very insoluble in all but a few things.
> 
> Finely divided Pd dissolving (in HCl) is usually more due to dissolved oxygen in the HCl making Cl2.



So this is why hot HCl is less likely to dissolve Pd than cold? 

Or why Au sponge is best cleaned with cold HCl?


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## Lou (Apr 3, 2020)

Boiling HCl rids it of dissolved O2/Cl2.

The O2 makes the Cl2. This is why muriatic gets yellow after being exposed to air.


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## Sorrycantseeme (Apr 3, 2020)

So my situation can only be 3 things i guess. 
1- the pgm are at the bottom of container mixed with alumina 

2 Pgms are mixed with alumina and some in solution 

3 All Pgm are in solution. 

So im going to find hotplate and make some stannous then test solution. 

Im still looking for what to do about the test sample that hcl didnt dissolve.


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## Sorrycantseeme (Apr 4, 2020)

Yesterday my sample had alot of black in it and hcl didnt seem to do much too it, today heres what it look like
https://photos.app.goo.gl/qsHqhMSLsULcor9r9


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## Yggdrasil (Apr 4, 2020)

I stand corrected Lou.
This was told to me by a member a long time ago, and I frankly forgot to check if that was so


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## kurtak (Apr 4, 2020)

Yggdrasil said:


> Ok, I believed that that had to do with autocatalysts and the high heat they had been subjected to.
> High heat could create PdO and that would dissolve in HCl.
> This is an industrial catalyst on large sheets.
> Will that be an issue here as well?



Yes auto CATs - It was "many" years ago now that I worked on that project with the scrap yard & I don't remember every thing any more & I certainly don't have all the answers (then or now) - (PGMs are hard/tricky in the first place)

That said - this is what I know "for sure" - "some" (but not all) CATs would put the Pd into solution "instantly" as soon as you poured the HCl to them

It needs to be noted that when we did this we processed the CATs according to the type &/or car brand they came from so we would know the recovery per type/brand (recovery based on price paid for type/brand CAT) 

This (Pd going into solution with "only" HCl) was always the result of the same type/brand CATs & those type/brand CATs were always higher in Pd then Pt/Rh - where as CATs that where higher in Pt/Rh then Pd this did not happen with --- which is why I bring this up

According to Sorrycantseeme - his CAT is higher in Pd then Pt/Rh (.5 Pd - .1 Pt - .1 Rh)

the wash coat on his CAT is on SS & he is trying to recover the PGMs by dissolving the SS with HCl & the higher PGM is Pd --- therefore - though I do not know this for sure - the Pd may (or not) be going into solution with HCl while trying to dissolve the SS --- however - the SS may also be cementing the Pd back out of solution as fast as it is going into solution --- therefore - while SS is still present a stannous test will tell him nothing

However - once the SS is ALL dissolved - Pd may (or not) go into solution - if there is free HCl in the final dissolve of the SS --- therefore - it that point he needs be sure to test (stannous) at the end (&/or as he nears the end) of the SS dissolve as there may (or not) be Pd in that final dissolve 

In other words - what I know "for sure" is that I recovered "a lot" of Pd from CATs with nothing other the HCl

Why ? --- I don't know for sure - was it because the Pd was PdO - or was it because the Pd was VERY finely divided - or was it because the Pd was alloyed &/or present with other base metals (such as copper - which was found in "high" amounts in "some" CATs) ???? --- don't know - just know HCl "alone" would put Pd into solution

Kurt


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## Sorrycantseeme (Apr 4, 2020)

Thats solid info i definetly will not get rid of anything until i test with stannous.
The xrf did not show rhodium although i wish 
It did even at .1% would been nice.
Xrf 
Pd- 0.5%
Pt- 0.1
Au- -0.1

I am going to go to wallyworld and get electric 
Burner even though i have one already . 
Stannous test is crucial now more than ever .
Heres a link below to see what some of powder 
Looks like at bottom 
https://photos.app.goo.gl/ZWgh2Wc2JYUhm7yb8


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## Lou (Apr 5, 2020)

Removing the matrix/support metal with HCl yields iron and chromium chlorides and hydrogen gas and water.
The nascently generated H2 reduces PdO into Pd and makes the metals much more soluble in oxidizing and complexing media. The H2 also keeps them from going into solution. If your solution is producing hydrogen, then you are not solvating those precious metals to any extent worth caring over.

When you dissolve the residue--that which does not dissolve in HCl--in aqua regia or some other oxidizing and complexing medium, you will need to filter the precious metal containing pregnant solution free of the alumina, which will not substantially dissolve. If it's anything like what I've seen, then these pieces will be clear and in the rough shape of the corrugating/herringbone that it used to coat. Your solution will be chocolate brown.


I've actually processed many, many many tens of thousands of pounds of automotive foil converters and industrial pollution control modules.The way you're doing this is what I would call a sledge hammer. It works, but there's lots of waste and the risk of hydrogen gas which recommends against doing this on a 20K lb lot of these.


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## Yggdrasil (Apr 5, 2020)

Interesting as always Lou.
Just out of curiosity, could you suggest a couple of alternative *small hammers* to his approach :mrgreen: :lol:


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## Sorrycantseeme (Apr 5, 2020)

I dissolved some solder in hcl by lightly boiling. 
Is it possible i use to much solder , this time the solution is a little grey if i remember last i made it was clear
.Sorry nevermind i got it i tested against some solution i had that has pgms and it was good .


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## FrugalRefiner (Apr 5, 2020)

Yep. The grey was probably just suspended tin particles. Let it settle and use the solution. If it tests good against a known, standard solution, you're good to go.

Dave


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## Sorrycantseeme (Apr 5, 2020)

You guys are truly experts , although new problem but i was not suprised because the gentleman earlier in the post cautioned me about Pd going into solution with hcl.
So i tested the waste stream bins it appears theres nothing in solution . I will test again to be sure but the sample i had posted about earlier i noticed it had removed alot of the black material , to leave lighter material . I tested & it immediately turned color the link to video below.

https://photos.app.goo.gl/URdRvQ8GZBuPwXe68

It appears HCL has put PD into solution only on sample . This was cold Hcl & thanks i wasnt suprised cuz forum raised my awareness.

Now Im left with this concentrate of pgm & metals 
whats the next best move . I posted a video of my concentrates same material as sample , except i only decanted my original solution havent added anything to this , hopefully i can get a experts advise for beginner. 

https://photos.app.goo.gl/PmZv7wNoT8M3X1476

I really need the money , my father had a stroke 12 days before xmas & i was in middle of moving . Every second this forum members have taken to give advise is truly appreciated .theres so many approaches and techniques its confusing a bit but i ask alot of same stuff it seems because I feel like every step is crucial and its very stressful. 
I wake up with hope knowing a member on forum will take time from there day & thats what is so amazing to give guidance. Every reply is valued cuz whenever i see a new reply i feel confident and thankful that im getting years and years of advice from all aspects . Theres no way this wealth of knowledge can be obtained single handely .
I cant imagine if people around the world ever put differences aside on collaborated on any problem in whatever situation there would be nothing people couldnt cure or fix or build. This forum is truly a benchmark example because i have no idea how chemical reactions occur , a tiny bit but im blown away when i get advise and if ts right . I cant thank every 1 enough !!!!


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## Sorrycantseeme (Apr 6, 2020)

I split sample up in 2 containers , in both I water washed black pgm salt . 
1st- mix w/hcl pgm dissolved slowly 2 days 

2nd - I dissolved with hclh2o2 and it instantly dissolved . I tried to precipatate with sodium chlorate but no black pgms fall i test with stannous it turns orangish red . Why no precipatation.


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