# Refining catalytic converters [help needed]



## Shawn618 (Apr 28, 2014)

Hey guys! 

Shawn here. So I got my hands on a pretty neat cat not sure of the make and model of it, 
But I'm looking to refining it. Iv been refining gold for a while now and I am pretty comfortable with that process,
And with P.M's Aqua Regia but this has a few more steps involved, and I'm
Up to the the challenge with your help! Iv read Hokes book have Matthew wangs but I could still use some words from you,
So far the steps taken 

decanted cat
Grinder 1/2 honeycomb to powder 
Incinerating honeycomb in brick furnace 

Now I'm not sure if this honeycomb or the sulfur has completely burnt away,
So I'm not certain if I should move on to the AR, 

I'll post some pictures and let me know if you think it looks correct.


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## arsenic123 (Apr 30, 2014)

Oh boy!!! You made a very big mistake by grinding them. Here is the post that will tell you why you made a big mistake. 

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=49&t=20473


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## Shawn618 (May 9, 2014)

Not a problem I still have the other half intact, how do I go about that? 
Drop it in AR? No roasting or incinerating ?


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## butcher (May 9, 2014)

Shawn,
It is not that you cannot leach the crushed material, it is just more difficult.
I would incinerate the honey comb to remove carbon, oils, organics that can cause problems.
Aqua regia or one of the other methods can be used, HCl/NaClO (bleach, sodium hypochlorite) or HCl/ concentrated H2O2
Check out Kurtak's recent post you may find it very helpful.


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## kurtak (May 10, 2014)

Shawn

What you are doing here is considered a "small batch" which you can do without to much problem - I will explain what you need to do when I am done posting in this thread http://goldrefiningforum.com/phpBB3/viewtopic.php?f=51&t=20573 --- so hang on for a few days & I will get back to tell you what you need to do here

Kurt


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## Slayer-PGM (May 10, 2014)

kurtak said:


> Shawn
> 
> What you are doing here is considered a "small batch" which you can do without to much problem - I will explain what you need to do when I am done posting in this thread http://goldrefiningforum.com/phpBB3/viewtopic.php?f=51&t=20573 --- so hang on for a few days & I will get back to tell you what you need to do here
> 
> Kurt



Thanks Kurt. I will follow this thread too to get the idea. I am also having some few converter which I want to do on small scale. Waiting for your inputs. Thanks


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## Shawn618 (May 13, 2014)

kurtak said:


> Shawn
> 
> What you are doing here is considered a "small batch" which you can do without to much problem - I will explain what you need to do when I am done posting in this thread http://goldrefiningforum.com/phpBB3/viewtopic.php?f=51&t=20573 --- so hang on for a few days & I will get back to tell you what you need to do here
> 
> Kurt




Hey Kurt!

Awesome to hear from you!thanks for all this interest and support,

so i actually went ahead and tired both methods 
Hcl+NaNo3 and the Hcl+bleach(4%hypocholrite)
and am using Ammonium chloride,

lets call the AR beaker A and the Hcl/Cl beaker B

now i have used the Ammonium chloride on noxxed AR but it was poor mans ar to begin with so not a lot of noxxing to do.
and i had a somewhat white precipitate, kinda confused \...

also i had whole honeycombs in beaker B let it soak for 3 days and put it in a warm water bath each day and let it cool i as i added more bleach... than the last day i heated the bath water up and let it sit for 2hours than added Ammonium chloride
getting the same white/greenish drop.. maybe its my Ammonium chloride..? but i have a good source so not sure..

thanks for your time
Shawn


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## Slayer-PGM (May 13, 2014)

Shawn618 said:


> kurtak said:
> 
> 
> > Shawn
> ...




Please post pictures. A clear picture would be good. That will help the members to give suggestions. Post every pictures. By the way according to me HCL/CL leach would require atleast 7 days. Everyday you have to add little CL in to the HCL dipped combs. 3 days I am not sure would leach out the values properly.
By the way are you sure its of petrol engine? India is famous for CNG and diesel type cats. That is also affect the recovery.


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## kurtak (May 14, 2014)

Shawn618 said:


> kurtak said:
> 
> 
> > Shawn
> ...



Shawn 

Sorry for such a delay in responding but a have "a lot" on my plate right now

You are having a problem because you are trying to use a refining process (ammonium chloride) when you are still in the recovery stage of the process 

What you need to do is "first" recover your PGMs from the leach with a zinc drop (cementing) which will give you back your PGM black (Pd/Pt/Rh) you then re-dissolve the PGM black for the refining step

Kurt


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## Shawn618 (May 14, 2014)

Please post pictures. A clear picture would be good. That will help the members to give suggestions. Post every pictures. By the way according to me HCL/CL leach would require atleast 7 days. Everyday you have to add little CL in to the HCL dipped combs. 3 days I am not sure would leach out the values properly.
By the way are you sure its of petrol engine? India is famous for CNG and diesel type cats. That is also affect the recovery.[/quote]


Hey Slayer,

i will deff post some pics up soon, im having a few issues with my phone =( but will have things figured out for sure!
and 7 days you say?
thats not a problem at all.. i actually would be more satisfied let it soak for a longer time.

and when i got the cat he told me it was a diesel. dude even if i can recover 1g of pt im in profit..

i also have a foil cat not sure what to do with that, will leave it for a later project, 

but yea ill snap some pictures of the drop i have.. i dont toss any off my solvents as i am sure that there is Pd in the since it dissolves first,

thanks for your time effort and help friends =)

Shawn


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## Shawn618 (May 14, 2014)

[/quote]

Shawn 

Sorry for such a delay in responding but a have "a lot" on my plate right now

You are having a problem because you are trying to use a refining process (ammonium chloride) when you are still in the recovery stage of the process 

What you need to do is "first" recover your PGMs from the leach with a zinc drop (cementing) which will give you back your PGM black (Pd/Pt/Rh) you then re-dissolve the PGM black for the refining step

Kurt[/quote]

Hey Kurt, 

some solid information there! and take your time bro, you sharing this knowledge is a gift.
and i say this from all of us that we are grateful. 

now how many days do you recommend i let the honeycombs soak for?

and in what ratio would i add the CL
do i place it in a warm water bath?

also zinc bar? or zinc chloride?

sorry for all these questions but i find precious metal refining so damn interesting and am craving to learn  

thanks for all this support 
truly means alot 
your patawan :wink: 
shawn


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## Slayer-PGM (May 14, 2014)

kurtak said:


> Shawn
> 
> What you are doing here is considered a "small batch" which you can do without to much problem - I will explain what you need.
> 
> Kurt



Hey Kurt can you post step by step process for crushed honeycomb? I know how to leach a full cat by hcl/cl by Steve method but I am not getting success in crushed honeycomb. Can you tell us the percentage of chemicals or AR or hcl/cl is better and is it necessary to heat the AR and how many days leaching is advised?? Also pd is easy to recover so after recovering pd we have to move to Pt or RH. I mean steps for crushed combs. This will be to helpful for new people too. There are many threads to explain how to refine the black powder after adding zinc but I have not found steps for crushed combs in details. So the steps before refining would be helpful. I mean recovering the pgm from dust. 

Thanks


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## Shawn618 (May 15, 2014)

Slayer-PGM said:


> kurtak said:
> 
> 
> > Shawn
> ...




hey Slayer,

i know the question was not directed a me, however i have read Matthew Wang China's method in which he says,
thats it should be at an 18 percent ratio and should not exceed 25% and leach for a mininum 7 days with mixing the solvent continously.. and i think he mean to recover the black power re-disolve it and than drop Pt,Pd and Rh.. 

from my uderstanding... correct me if im wrong 

Thanks 
shawn


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## Slayer-PGM (May 19, 2014)

Thanks. By the way any news on Kurt? I am still waiting for his inputs and his knowledge on crushed combs and the way to refine small batches.


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## Shawn618 (May 19, 2014)

Slayer-PGM said:


> Thanks. By the way any news on Kurt? I am still waiting for his inputs and his knowledge on crushed combs and the way to refine small batches.





haha yea man me too! =) his knowledge is a gift but im sure hes busy and will get at us as soon as he can,

we can throw some questions out there and he can check em out when he has a chance. 

like right now i have a full honeycomb converter and a full foil converter.

the honeycomb one i have is 1/2 grinded into powder and 1/2 in full blocks 

and the foil is cut in half 

im kinda not too sure about what to do with it but im waiting for kurt, 

what i think i will probably do is :

take the powder and the whole pieces and throw them in a 5 gallon plastic container 
than fill it up with hcl untill it covers all the whole pieces completely... which i think should be about 2 liters of hcl
than add my bleach (CL) which is 10% sodium hypochlorite.. 

wait one week 

than use zinc to drop it.. now im not sure if i need a zinc bar or zinc chloride powder but ill have it figured out by the time we get there..

but after that ill wash that black powder (which i will have dropped with zinc ) and dry it.. 

than redissolve it ( now i have a question to whoever could answer it : do i redissolve it in AR or HCL/CL?)

than use ammonium chloride to get my bright orange powder.. 

than i will save my solvents because it still contains Pd. and Rh. 

i was also told that you cant melt that Orange powder into metallic platinum with a oxy torch
because its not good for your eyes (iv herd idk how true) 
melting the powder into its metallic state is my favorite part so that kinda sucks haha... 

but i have a friend who has a diamond factory so he uses a high grade furnace..

what do you guys think? 

thanks for reading 
Shawn


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## lazersteve (May 19, 2014)

I never crush my combs because the crushed material is so hard to get the solution to wet into. The surface of the comb is where the wash coat is applied, so crushing only complicates recovery and filtration.

I never mix foil types with combs or beads. I keep all types separated and process in batches. 

Do not process metal foils cats in HCl-Cl.

Extraction using HCl-Cl is sped up slightly by gently heating between 30-60C and adding the chlorine as in small doses over the course of the reaction. Producing too much chlorine all at once is only creating a cloud of poisonous gas, as chlorine is not very soluble in HCl at the reaction temperatures. 

Chlorine should be added so that it enters the solution from the bottom of the reaction. This allows the gas to pass through the comb structure where the values are. Pouring the Clorox on top of the reaction produces chlorine at the surface of the solution, most of which escapes into the air and is useless for extraction.

Circulating the HCl-Cl solution through the structure of the comb aids in extraction. 

Check your cats before you begin extraction to make sure they contain PMs. There are many thieves out there that sell 'pre-washed' cats, still in the can. Processing a small sample of the comb in a test tube and testing with stannous chloride will detect the presence of Pd and Pt. Processing the crushed material in a sulfate melt followed by stannous testing will detect Rh. Do not assume your cats contain PMs unless you have tested a sample and confirmed such. Do not run larger batches until the small scale tests are found to be positive on each cat.

I hope this helps.

Steve


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## Shawn618 (May 20, 2014)

lazersteve said:


> I never crush my combs because the crushed material is so hard to get the solution to wet into. The surface of the comb is where the wash coat is applied, so crushing only complicates recovery and filtration.
> 
> I never mix foil types with combs or beads. I keep all types separated and process in batches.
> 
> ...




Hey Steve, 

very eye opening information there, 

my question was what would be the host to drop the Pt.
i read ammonium chloride would do the trick.. but that guide also 
suggested to grind and incinerate the combs... 

i was told zinc by Kurt but not sure in what forum.. 
id also like to be explained what reaction takes place.. 
i feel its very important to know why you do what you do.. 
rather than just knowing what to do.. thanks

also how do you go about the foil converters? 
any threads on that... cant seem to find much 
with my searches.. 

thanks alot Steve 

Shawn


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## kurtak (May 20, 2014)

Will try to post something tomorrow

Kurt


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## lazersteve (May 20, 2014)

I prefer using potassium chloride to precipitate the Pt. The primary reason for this is that the resulting potassium salt is easier to wash and converts back to Pt metal without the hard to manage ammonium chloride vapors.

The zinc is best applied as turnings. I find that approximately 0.5 to 1.0 inch wide cornets of zinc turnings to have the right surface area to dissolve evenly while producing the best consistency mixed PGM blacks (settle fast and rinse easily). The starting PGM concentration of the solution is another factor that affects the consistency of the resulting mixed blacks.

The dissolution equations of Platinum, Palladium, and Rhodium in a Chlorine milieu are well documented. The primary factors affecting the reaction efficiency and rate are HCl concentration, reaction pressure, temperature, and time of exposure of the wash coat to the solution. Secondary factors include PGM salt concentration and free chlorine.

I have recently found that pretreatment of the combs with formic acid at room temperature can greatly increase the extraction of the PGMs.

I do not process foil cats so I can not help you with them. Here's a quick search result for foil cats

Foil Cats Search

Steve


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## Slayer-PGM (May 20, 2014)

lazersteve said:


> I prefer using potassium chloride to precipitate the Pt. The primary reason for this is that the resulting potassium salt is easier to wash and converts back to Pt metal without the hard to manage ammonium chloride vapors.
> 
> I have recently found that pretreatment of the combs with formic acid at room temperature can greatly increase the extraction of the PGMs.
> 
> Steve



Hey thanks for the info Steve. I have your CD and in the CD you have used ammonium chloride and Sodium chlorate for PT and PD. Now your recent study tells you that potassium chloride is better that the ones in your CD? So we should use that? 

Also what exactly you mean by pretreatment of the combs with formic acid? It it like dip the whole crushed honeycombs in Formic acid before putting in HCL and adding chlorine everyday or Using formic acid instead of HCL? 
Also if we dip it formic acid which PGM will be dissolve in formic acid? Thank you.

Good to see you on forums..


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## lazersteve (May 20, 2014)

As with any process, they always evolve over time. 

I currently use KCl for Platinum precipitations.

A brief soak in formic acid appears to activate the PGMs on the combs to go into solution. I really don't know why at this point, but it may be the active hydrogen provided by the formic acid. It may also be related to the removal of the carbon build up in the cats by the formic acid. Dip the combs in a room temperature bath of formic acid and soak for 30 to 60 minutes (exact time must be determined experimentally on samples as each comb is different due to use and cat operating conditions). Triple rinse with water and proceed with the HCl-Cl routine. 

Formic acid pretreatment can increase extraction efficiency to over 90-95% in many cases. 

Continue to use the same formic acid bath on each new batch of cats until it no longer aids in the extraction of the PGMs, then replace.

Steve


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## Lou (May 20, 2014)

It's the reduction of the oxides, Steve. 

PdO and Rh2O3 are both rather acid insensitive. 

It is a standard analytical procedure to use sodium acetate/sodium formate to reduce these oxides before doing a wet chem digest and spectroscopy.


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## arsenic123 (May 20, 2014)

lazersteve said:


> As with any process, they always evolve over time.
> 
> I currently use KCl for Platinum precipitations.
> 
> ...



Thank you for this great tip. So basically its only used to dip and later we can just discard the acid, right?
Also any great advantage in using KCL and should we use in the same way like ammonium chloride dissolved in water for precipitation? its just in place of ammonium chloride we have to use KCL?

Thanks for the tips.


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## Lou (May 20, 2014)

The advantage is that ammonium chloride has complicated waste treatment (needs oxidation with hypochlorite). Ammonium chloride is a source of ammonia when metal containing solutions go through standard hydrolytic waste treatment processes. That ammonia is a chelant which binds nickel, copper, and other metals as amine complexes that do not waste water treat well without the use of sulfides.

To be honest with you, using KCl on solutions obtained directly from catalytic converter leaching will probably result in no precipitate and if it did, most of the PGMs would remain dissolved in solution. This would indicate that the solution would need cementation treatment. Generating large volumes of aqueous PGM solutions is not a good idea: for this reason alone I would suggest against leaching the converter. It might be useful as an educational experience, but it is not something for making money.


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## Shawn618 (May 21, 2014)

lazersteve said:


> I prefer using potassium chloride to precipitate the Pt. The primary reason for this is that the resulting potassium salt is easier to wash and converts back to Pt metal without the hard to manage ammonium chloride vapors.
> 
> The zinc is best applied as turnings. I find that approximately 0.5 to 1.0 inch wide cornets of zinc turnings to have the right surface area to dissolve evenly while producing the best consistency mixed PGM blacks (settle fast and rinse easily). The starting PGM concentration of the solution is another factor that affects the consistency of the resulting mixed blacks.
> 
> ...





Hey Steve! 

WOW! awesome stuff here man! so zinc turning to precipitate the PMG's from our main solution and potassium chloride for the solution dissolved with the black PMG power?
and thanks for the search up alot of good info there aswell, the foils still feel like a next level thing.. 

thanks alot 
Shawn


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## arsenic123 (May 21, 2014)

lazersteve said:


> As with any process, they always evolve over time.
> 
> Continue to use the same formic acid bath on each new batch of cats until it no longer aids in the extraction of the PGMs, then replace.
> 
> Steve



How can we know that formic acid stopped aiding in the extraction of the PGMs? After dipping in the formic acid for say about 1-2 hour we follow the normal procedure of HCL/CL everyday and that would leach out the PGM with a postive test of stannous for PGM. So even if we dont dip in the acid we will still get the PGM's so how can we come to know that formic acid is not helping or helping or it has stopped aiding in the extraction. I hope you got you point. 
Thanks


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## lazersteve (May 21, 2014)

Extraction is completed when small scale testing of the left over material shows no sign of PGMs. If you have completed a run on the combs and want to confirm your work is done, simply place a small sample of the left over comb in a test tube and extract with AR and heat. Test the AR with stannous and see if any new PMs are present. I demonstrate this on the Fundamentals of Platinum and Palladium DVD which deals with cat recovery and recycling. On the video I test a sample of the beads and find additional Pt is in the material after the initial extraction.

Typically in extraction chemistry three proper leach cycles produces the maximum recovery. After three extraction cycles, the law of diminishing returns kicks in and you are spending more time, chemicals, and money on the extraction process than additional extraction cycles produce in PM value. 

Testing is the best means of determining the end point.


Steve


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## lazersteve (May 21, 2014)

Shawn618 said:


> ... awesome stuff here man! so zinc turning to precipitate the PMG's from our main solution and potassium chloride for the solution dissolved with the black PMG power?...Shawn



Correct. Use Zinc turnings to scavenge your extraction solution and KCl to precipitate the colored PGM salts from the more concentrated solutions after the blacks are redissolved. Just as I demonstrate on the DVD, but use zinc turnings, not fine mesh zinc on the first go around, and KCl, not NH4Cl on the second.

Steve


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## arsenic123 (May 21, 2014)

lazersteve said:


> Extraction is completed when small scale testing of the left over material shows no sign of PGMs. If you have completed a run on the combs and want to confirm your work is done, simply place a small sample of the left over comb in a test tube and extract with AR and heat. Test the AR with stannous and see if any new PMs are present. I demonstrate this on the Fundamentals of Platinum and Palladium DVD which deals with cat recovery and recycling. On the video I test a sample of the beads and find additional Pt is in the material after the initial extraction.
> 
> Typically in extraction chemistry three proper leach cycles produces the maximum recovery. After three extraction cycles, the law of diminishing returns kicks in and you are spending more time, chemicals, and money on the extraction process than additional extraction cycles produce in PM value.
> 
> ...


That is what I was afraid that I couldn't make you understand my point, my bad, sorry. I will try once again. I know that we can test and see if any PGM is remaining in combs with a little sample but even if I don't put formic acid leach before any process this is the actual process that testing till we get no stannous test but I am not worried about those processes. I am just asking about formic acid step and you had told that you can discard the formic acid if it is not helping in recovering PGM and then you can discard the formic acid but what is the test or trick to know that formic acid is not helping now. Normally 3 leach is normal stuff we do even if we dont put in formic acid . your point "Continue to use the same formic acid bath on each new batch of cats until it no longer aids in the extraction of the PGMs, then replace." how can we come to know that it is no longer aiding in extraction of PGM. Normal 3 leach without formic pre treatment will also give negative stannous test. 
Basically I am asking about formic acid. I hope this make sense. 

Thanks


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## lazersteve (May 21, 2014)

Formic acid will produce bubbles when it is reacting (oxygen ?). No bubbles, no reaction. When bubbles cease, change your formic. 

Steve


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## Lou (May 21, 2014)

Carbon dioxide.

Beware using formic with some strong acids, particularly sulfuric--it can make carbon monoxide.


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## arsenic123 (May 21, 2014)

Thank you Steve and Lou. Great tip.


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## kurtak (May 22, 2014)

Shawn & arsenic

Sorry for the long delay on getting back to this - I have been very busy working on cleaning up the estate of my uncle who recently died

I see that Steve & Lou have already replied with much "good" advice

Concerning processing crushed material which it appears you both have - you are far better off smelting it then trying to leach it - the problem with trying to leach crushed material (as Steve already pointed out) is in wetting it - in other words the problem is in getting your leach to stay in contact with the ceramic substrate & to do so as fresh acids to preform the task of leaching

To achieve this the material needs to be continually stirred to keep the material in suspension in the leach so that it can have continual contact with fresh acid - other wise the material will settle - & when it does it settles fast hard & tight leaving your leach on the top where it is ineffective in doing its task

The other problem is in filtering &/or washing the leach out of it - & for the same reason - the material settles fast, hard & tight preventing effective washing - your best option here is going to be wick filtering & it needs to be a very thin layer of material on top of the filter because if you have to much material on top of the filter it will act like the clay used to seal the bottoms of ponds which will in turn prevent even wicking

If we are talking about a "small" amount of material (a couple of CATs) you could get away with trying to do it in a crock pot (we had an actual 20 liter reaction vessel with stirrer & heat mantle when we tried this at the scrap yard)) --- I would use AR in this case not HCL/CL as my leach - the AR needs to be hot (the reason for a crock pot) & you will need to stir the media as often as possible if you can't provide continual stirring - the leaching will be a day long process & the washing filtering a couple days (waiting on the wicking)

Be aware that you will not be able to leach crushed CAT material with any degree of success on anything larger then a couple of CATs - period - & even on a couple CATs of material your success is only going to be limited for the time & chemical put into it

Smelting (if you can) is really the way to go with crushed material in which cased (based on Lou's good advise) you need to use cryolite as you flux 

Kurt


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## Shawn618 (May 22, 2014)

Hey guys,

Kurt, sorry for your loss buddy you have my condolences..
(always here for a talk feel free to PM)

thanks for all this info guys i seem to have a good idea of what im doing.. 

i as of now have a 5 liter glass jar with about 1.6L HCL and Sodium Hypochlorite in it 
with 1 full CAT which was 60 percent whole and 40 percent crushed.. 
i added both in the jar the power settles on the bottom and i stir it every chance i get 
and the wholes rest on top.

iv been leaving it out in the sun so it naturally heats up for 90-100 degrees F and at night it would cool back down 
and i add about a spoon for concentrated bleach powder which is mostly Sodium Hypochlorite.. its been about 2 days and the solution is yellow-orangish 

i believe im expecting a reddish tint? 

what is a good Wick TEK
this is the first iv herd of this..

is it something like that cake technique used with cyanide in gold recovery? 
...........

ALSO! can i melt Pt with my butane torch?



ill post pictures soon im having phone issues right now.. 

thanks for all your support! Steve, Kurt, lou, slayer, and Arsenic!
blessed to have an amazing forum and people like you guys!


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## arsenic123 (May 23, 2014)

kurtak said:


> Shawn & arsenic
> 
> Smelting (if you can) is really the way to go with crushed material in which cased (based on Lou's good advise) you need to use cryolite as you flux
> 
> Kurt



Thank you for the reply. Smelting would require furnace right? I have heard that plasma arc furnance is best option to go for crushed honeycomb. Also can this be used for cryolite?
http://www.indiamart.com/fsnproductsindia/foundry-chemicals.html#sodium-cryolite

Or anyone from this page.
http://dir.indiamart.com/cgi/catprdsearch.mp?ss=cyrolite

We have sodium cryolite, potassium cryolite, cryolite powder, etc. So I am a bit confused. 
Thanks Kurt for the post.


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## 4metals (May 23, 2014)

Available here in the states from

http://www.washingtonmills.com/products/cryolite/


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## kurtak (May 24, 2014)

Johnson Matthey uses a reverberatory furnace - here is a video about JMs process

http://www.jmrefining.com/page-view.php?pagename=Video-page&language=

Kurt


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## newt3947 (Dec 21, 2014)

This is my first post, but I have been reading the forum for a couple of years. Thanks for all the great info.
I am trying my hand at processing catalytic converts. I use Hcl and bleach to the leach the pgm's. I cement the pgm solution with aluminum. After the pgm's drop and settle I'll filter and then transfer the black powder to a beaker and wash with distilled water. Here is where I am having the first problem. Often times I have to leave the black powder in the water for several days. When I come back to it the pgm's I am noticing that some of the pgm's have dissolved back into the distilled water. That to me is odd and I don't understand why that is happening. The water tests positive with stannous. Should I plan to go directly to AR after dropping the pgm's? Why are the pgm's dissolving in the water? If I filter the water, add Hcl, and then add the aluminum again, then I will cement the black powder again.

Another problem I am having is precipitating the platinum with KCl. I dissolved some black powder in AR, denoxed it, and reduced down to a concentrated solution--deep burgundy color. I then added some KCl in small amounts until I did not see any further reaction. I ended up with a canary yellow colored precipitant and the solution continued to be a burgundy color--I assumed the other pgm's where still in solution and that is why the color did not change. My problem occurred when I went to filter the precipitant. I do not have a vacuum filter so I used a Buchner funnel and coffee filters. As I was adding the distilled water to rinse the precipitant, the precipitant began dissolving again. When I was finished there was only a fraction of the precipitant left in the filter. I didn't know what to do so I boiled off the water to get a concentrated solution to see if the precipitant would return--it did not. After the solution cooled, it crystallized into brownish/red crystals. Since boiling off the water didn't make any difference, I added distilled water back to the crystals and I now have a burgundy solution and a small amount of yellow precipitant (from the filtering). So, any suggestions as to what I can do now? Should I try to cement the pgm's again to get them out of solution and start over? Why did the precipitant dissolve with distilled water? Is a vacuum filter required?
Thanks for your help.


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## nickvc (Dec 21, 2014)

The refining of PGMs is not the easiest and the one thing to remember is that many PGM salts are water soluble, go back and read Hoke its explained there I think, if not its been posted on the forum and can be found using the search function top right of your screen.


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## newt3947 (Dec 21, 2014)

I have been reading the forum for 2 years, so I know how to search the forum for answers. I have not been able to find the answer to my questions. There is a huge data of information on the forum and it is difficult to find the right thread that would give me the answer to my questions. Your post would have been useful if you directed me to a thread that addressed the questions that I asked. I have read Hoke and refer to it constantly. I have read other authors also. I have been processing gold without difficulties for 2 years because of this website. I have bought and viewed several DVDs that have been recommended on this forum. I hesitated to make a request for help on this forum because I thought I would be treated as an many "newbies" are treated. I'm not a chemist, but I do have a MD degree, so I'm not asking these questions out of stupidly. I am doing the PM refining as a hobby. I don't appreciate your response, and if you don't have something constructive to contribute to this thread then you need to keep your negative attitudes to yourself. This is a great website and there are some really smart people on this website. I want the smart people to respond to my questions, not the hall monitors. I don't want to tick anybody off, but your response was not helpful.


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## jimdoc (Dec 21, 2014)

newt3947 said:


> I have been reading the forum for 2 years, so I know how to search the forum for answers. I have not been able to find the answer to my questions. There is a huge data of information on the forum and it is difficult to find the right thread that would give me the answer to my questions. Your post would have been useful if you directed me to a thread that addressed the questions that I asked. I have read Hoke and refer to it constantly. I have read other authors also. I have been processing gold without difficulties for 2 years because of this website. I have bought and viewed several DVDs that have been recommended on this forum. I hesitated to make a request for help on this forum because I thought I would be treated as an many "newbies" are treated. I'm not a chemist, but I do have a MD degree, so I'm not asking these questions out of stupidly. I am doing the PM refining as a hobby. I don't appreciate your response, and if you don't have something constructive to contribute to this thread then you need to keep your negative attitudes to yourself. This is a great website and there are some really smart people on this website. I want the smart people to respond to my questions, not the hall monitors. I don't want to tick anybody off, but your response was not helpful.




On the forum for two years, then on the path of getting booted off within 24 hours of your first post.
Real smart.

Jim


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## butcher (Dec 21, 2014)

newt3947,
I really do not understand your complaint, NickVc really gave you good advice, answered your question, and spent time trying to point you in the direction where the answers to your questions can easily be found, he was helpful as usual, and always gives members great advice.

How could he have been more helpful, what should he have said, that could have helped you more?
should he have provided you with the threads from his memory, or spend time from his business to find threads you may or may not find interesting or helpful?

Your request, or expectations are just ridiculous, the only one I see with a negative attitude here is you, in your reply to someone trying to help you, I am not a hall monitor, and neither is NickVc, if you do not want to tick the forum off, you sure do not know how not to go about that, do you, it looks to me like you just spit in the face of those willing to spend their time to help you.

I am sure my response here will not be helpful to you, but maybe someone else may find it helpful.

I do not have much constructive to add here, you have done a good job of seeing to that, by the way you have reacted to a fellow member trying to assist you.


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## necromancer (Dec 22, 2014)

butcher said:


> newt3947,
> I really do not understand your complaint, NickVc really gave you good advice, answered your question, and spent time trying to point you in the direction where the answers to your questions can easily be found, he was helpful as usual, and always gives members great advice.
> 
> How could he have been more helpful, what should he have said, that could have helped you more?
> ...




i do remember reading a post on leaching pgm's with your same method newt. i can't see reading through 20 or 30 post titles to find a answer. i will even help look for it.


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## necromancer (Dec 22, 2014)

does this help you newt........ search time from last post = 10 minutes

http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=51&t=14932

EDIT: search word was ""honeycombs""


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## newt3947 (Dec 22, 2014)

I apologize for my remarks. I have been searching the forum for the answer to my problems and have spent hours reading and searching. I guess I'm just frustrated. I was hoping someone could enlighten me concerning the process of using KCl to drop platinum. The reaction I got when rinsing the platinum salt surprised me and I don't know what to do to correct it. I did something wrong but I don't know what it was. I was just wondering if anyone else had had a similar issue.
Again, I apologize for my remarks. I'll keep looking. The answer has to be in the forum somewhere.


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## Lou (Dec 22, 2014)

I just wish people would stop with the catalytic converter leaching.

Too much mess and too much risk for too few dollars.


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## FrugalRefiner (Dec 22, 2014)

newt3947 said:


> I apologize for my remarks. I have been searching the forum for the answer to my problems and have spent hours reading and searching. I guess I'm just frustrated. I was hoping someone could enlighten me concerning the process of using KCl to drop platinum. The reaction I got when rinsing the platinum salt surprised me and I don't know what to do to correct it. I did something wrong but I don't know what it was. I was just wondering if anyone else had had a similar issue.
> Again, I apologize for my remarks. I'll keep looking. The answer has to be in the forum somewhere.


newt,

I'm not sure where you got the idea to use potassium chloride (KCl) to precipitate platinum. Hoke used ammonium chloride (NH4Cl), which creates the orange powder platinum ammonium chloride. As already mentioned (and described by Hoke) the PGM salts are dissolved by plain water, so she suggests:


C. M. Hoke said:


> So dissolve a handful
> of pure ammonium chloride in a pint of water, making up roughly
> a 15% solution, and put it in your small wash-bottle. Label this
> little wash-bottle, so as not to confuse it with the big one containing
> ...





> We use ammonium-chloride-water
> because some of the powder would dissolve in plain water,
> but very little dissolves in ammonium-chloride-water. But use as
> little as will do the work.


As Nick suggested, you'll find answers to some of your questions in Hoke's book.

Dave


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## Lou (Dec 22, 2014)

If he's going to use anything, use KCl.


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## FrugalRefiner (Dec 22, 2014)

Thank you for clarifying that Lou. 

Dave


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## g_axelsson (Dec 22, 2014)

Here is a post from Lazersteve where he uses potassium chloride.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=51&t=20533&start=20#p211828

As I understand it, potassium hexachloroplatinate have a very low solubility in plain water. So there are only two possibilities, either you didn't use pure water or the salt you had wasn't K2PtCl6. You can't fool nature.

... scratch that, according to http://www.chemicalbook.com/ChemicalProductProperty_EN_CB8752907.htm has a solubility of 50 g/L (95 ºC), did you use hot water?

Further research gives : http://bitnest.ca/Rhodium/chemistry/platinum.recovery.html
"If the solution becomes too cold, a considerable amount of sparingly soluble potassium hexachloroplatinate(IV) may precipitate."

So, the search of the solubility goes on and the last reference I found was http://www.espimetals.com/index.php/msds/231-potassium-hexachloroplatinate
Solubility in H2O: Slightly in cold, soluble in hot

Try washing in cold water and see what happens.

Göran


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## Lou (Dec 22, 2014)

The issue people seem to have with all of this catcon stuff is that they're leaching a converter with at most 2,000-3,000 ppm Pt in it (2-3 g / kg). They're doing this with lots of concentrated acids, probably a solid to liquid pulp ratio of at least 1:2. Then, after they've rinsed the heck out of the converter, they try to precipitate the platinum out by making a toxic, nasty chloroplatinate. If it even precipitates at all, some get a small bit of precipitate contaminated by other metals, with likely full well half or more of the values remaining in solution, not realizing that under the best circumstances they'll still always leave a few tenths of a gram Pt/L in the leachate. Of course this is a solution that can't be used for re-leaching due to the precipitant having been added. Then, they have to use copious quantities of zinc or lye or both to cement the rest of the values presenting additional exposure routes, yield issues, etc. They may now be left with a value-barren saline solution of tetraammine-complexed zinc if ammonium chloride were used. This is all presuming they read far enough on how other people are doing them (not that it makes it right). Fun to waste treat. All of that for a few hundred dollars?

:roll: 

I think I've had enough with the catalytic converter craze. It isn't safe, smart, or responsible to process these converters by aqueous hydrometallurgy without the use of very advanced, proprietary resins that are expensive and come with their own limitations. It is probably above 99.9% of members' capabilities here to safely work with platinum, let alone large quantities of the dilute sauce coming from converters.

I've spent a lot of time messing about with converters many different ways and I can say that they're best sold to someone else who goes to the smelter.

Lou


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## nickvc (Dec 22, 2014)

Lou said:


> The issue people seem to have with all of this catcon stuff is that they're leaching a converter with at most 2,000-3,000 ppm Pt in it (2-3 g / kg). They're doing this with lots of concentrated acids, probably a solid to liquid pulp ratio of at least 1:2. Then, after they've rinsed the heck out of the converter, they try to precipitate the platinum out by making a toxic, nasty chloroplatinate. If it even precipitates at all, some get a small bit of precipitate contaminated by other metals, with likely full well half or more of the values remaining in solution, not realizing that under the best circumstances they'll still always leave a few tenths of a gram Pt/L in the leachate. Of course this is a solution that can't be used for re-leaching due to the precipitant having been added. Then, they have to use copious quantities of zinc or lye or both to cement the rest of the values presenting additional exposure routes, yield issues, etc. They may now be left with a value-barren saline solution of tetraammine-complexed zinc if ammonium chloride were used. This is all presuming they read far enough on how other people are doing them (not that it makes it right). Fun to waste treat. All of that for a few hundred dollars?
> 
> :roll:
> 
> ...



Well at last someone else is singing from the same hymn sheet and a smart( very smart ) moderator.
I have tried for many years to get members to understand the dangers and difficulties of refining high grade PGMs let alone cats.


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## goldsilverpro (Dec 22, 2014)

Great post, Lou. You hit the nail on the head. I've played with cat material and would never go through the hassle required to do this chemically. Also, I've never been convinced it's profitable. Also, it's not easy to get the rhodium.

If you search, you will find 6 or 8 patents that mechanically separate the metals in the cat material from the waste, by grinding and then using various separation methods (most used specific gravity) and equipment. Most claimed 80%-95% recovery, if I remember right. Even in the 80% range, I would be more than satisfied. I played around with these for awhile and had pretty good luck, as far as I could tell with my limited analytical resources at the time.


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## Anonymous (Dec 22, 2014)

Oh Lou that's just so not fair especially when I've just got my first source of platinum. 8) 8) 8) 

I'm going to go and cry in my beer now and sulk..... 

:twisted: :twisted:


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## nickvc (Dec 22, 2014)

Jon if you have platinum metal just remove the base metals and recover the Pt, as Lou said PGM salts have many dangers, leave them to the pros!


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## Anonymous (Dec 22, 2014)

nickvc said:


> Jon if you have platinum metal just remove the base metals and recover the Pt, as Lou said PGM salts have many dangers, leave them to the pros!



I know that Nick I'm just joshing with the guy. 8) 8) He'll come back and slap me if he feels like it. I've got broad shoulders and I won't cry too hard. :shock:


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## nickvc (Dec 22, 2014)

With PGM salts I don't josh they are nasty and downright dangerous, I don't want anyone hurt trying to refine PGMs leave it to those with the right equipment...
Jon I know you are playing but realise some things really can be fatal, we can't be seen to advise or condone dangerous methods or processes here on the forum, not all our members will understand your humour and would you really want to be responsible for harm to another, knowing you I guess not!
If you want to play do it by PM and not on open forum, we need to be united on the forum about any risks or dangers that newbies could try that are posted here.


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## nickvc (Dec 22, 2014)

As an aside may I say that newt has sent me a PM offering his apologies which I accepted with no issues, I don't take offence easily and only think of the well been and safety of all the present and future members of the forum.


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## necromancer (Dec 22, 2014)

spaceships said:


> nickvc said:
> 
> 
> > Jon if you have platinum metal just remove the base metals and recover the Pt, as Lou said PGM salts have many dangers, leave them to the pros!
> ...




even in text form that was very funny (in a joking very funny way)


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## Anonymous (Dec 23, 2014)

nickvc said:


> With PGM salts I don't josh they are nasty and downright dangerous, I don't want anyone hurt trying to refine PGMs leave it to those with the right equipment...
> Jon I know you are playing but realise some things really can be fatal, we can't be seen to advise or condone dangerous methods or processes here on the forum, not all our members will understand your humour and would you really want to be responsible for harm to another, knowing you I guess not!
> If you want to play do it by PM and not on open forum, we need to be united on the forum about any risks or dangers that newbies could try that are posted here.



No dramas Nick. You're probably right, people who know me will see the humour as completely separate from the safety issue. Others won't!


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## kurtak (Dec 25, 2014)

Lou said:


> I've spent a lot of time messing about with converters many different ways and I can say that they're best sold to someone else who goes to the smelter.
> 
> Lou



And that is the bottom line fact & truth spoken with very real words of wisdom :!: :!: :!: 

I spent right at a year working with a scrap yard (& as Lou said) trying "many different ways" to recover & refine the PGMs from CATs

Conclusion at the end of a years time & money invested --- "they're best sold to someone else who goes to the smelter." (notice there is a period at the end of that remark)

If you think you can process CATs on any volume & make a profit - FORGET IT - waste treatment alone will kill you - let alone time invested, chem & equipment cost

Its one thing to leach a "few" CATs to get a few grams of PGMs to play with to learn about PGMs - but there is NO WAY you are going to set up to process them on any volume to make a profit. (& that's a period at the end of that statement)

Kurt


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## kjavanb123 (Dec 25, 2014)

Kurt,

I read your post about how different methods to process cats were used and turned out, but there was a mentioning using induction cryolite as flux would seem less chemical waste and higher recovery rate. Is this a correct observation?

Also a friend of mine who is purchase ewaste and cats for Nippon PGM refinery in Japan also mentioned using Fe as collector metal.

Regards
Kevin


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## kurtak (Dec 26, 2014)

kjavanb123 said:


> Kurt,
> 
> I read your post about how different methods to process cats were used and turned out, but there was a mentioning using induction cryolite as flux would seem less chemical waste and higher recovery rate. Is this a correct observation?
> 
> ...



Keven 

First let me say I am sorry for not replying to the PM you sent me - I got "very busy" with other things 

The short answer to your question is NO :!: 

There is absolutely NO WAY (whether leaching or smelting) that a little guy like you or I can process CATs & make a profit

Why :?: --- because even if you recovered 100% of the PGMs its not going to be enough to cover the cost let alone make a profit & that's because even at 100% recovery you can not operate on a large enough scale to produce a "value added" product to sell at a profit --- that's how companies like Johnson Matthey or Nippon or BASF make a profit - they produce "value added" products - from the PGMs they recover & refine - which they then sell at well over spot & they do so on an "industrial scale" 

Everyone "thinks" - that a company like Johnson Matthey is making all of its money because if they pay you $100 for a CAT then they are pulling $200 (or more) worth of PGMs out of that CAT --- that's just not true --- they produce "products" out of the PGMs they recover & refine & those "products" have an "added value" that are sold for WELL OVER spot - that's where & how they make money

So - because they make their money on the value added products they produce (& not on the actual recovery/refining process) they can pay top dollar for raw material

Big companies can pay 80% of spot for the PGMs in CATs because of the products they produce from it --- have you ever tried to buy a platinum crucible - or a platinum plated anode/cathode - a platinum crucible that is only 24 grams goes for several thousands dollars --- can you get several thousand dollars for 24 grams of platinum you recover from CATs ------- NOOOOO

The profit is not in the recovery &/or refining of CATs --- its in producing value added products made from the PGMs recovered & refined from CATs

Lou hit the nail on the head when he said --- "I've spent a lot of time messing about with converters many different ways and I can say that they're best sold to someone else who goes to the smelter." 

Kurt


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## g_axelsson (Dec 26, 2014)

If anyone thinks that a company like Johnson Matthey is buying cats to refine at a cost larger than spot, that's just not true. Any big company that could cut cost by buying metal at spot instead of refining would do that. Whatever their cost is to refine the cats after buying them at 80% we can be sure that it is not above spot or they would be paying less or buying from the refinery that could do it cheaper.

Göran


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## kurtak (Dec 26, 2014)

Kevin (&/or anyone else that thinks they can process CATs & "PROFIT" by doing so)

Companies like Johnson Matthey - BASF - Nippon etc. do not make their "profits" from the recovery & refining end of processing CATs --- they pay top dollar to acquire this material in order to fuel a much larger business of making value added products out of the PGMs recovered & refined from the CAT material they acquire by paying TOP (scrap) dollar for it

Example - Products made by Johnson Matthey - http://www.matthey.com/about_us/productsandtechnologies

For every ozt of PGMs JM recovers from CAT material (which they pay a little under spot for) they make several thousand dollars "over spot" when it goes out the door as those "value added" products

In other words - if ALL JM did was buy CAT material to refine & sell as nothing other then refined PGMs - they would go broke paying the price they pay to acquire the CAT material --- & so will you

Kurt


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## nickvc (Dec 26, 2014)

I tend to agree with Kurt the big boys do buy below spot from their customers or run metal accounts for their customers to pull off further products but the real margin is in those products and having a ready supply of raw materials on hand helps to reduce banking costs.
The refiners and metal dealers are certainly not charities and make good profits from volumes charges and re supply of material to the end users.
If Lou has said this can't pay I would really listen to him, if your doing it for fun or the experience fine of you have the right equipment but in volume you can't beat the payouts from the big companies who use immense arc furnaces running 24/7 . The values left in your material if even done really well will be of more value than the charges or retentions the big companies levy.
To get a good return simply de can crush and mix properly and assay before shipping.


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## golden-puncture (Jun 27, 2018)

i did a mistake and i do not know what to do? as i get hcl/cl leach solition. then i commonly use zinc to get the black powder. later on in the stock pot i add some zinc and then i can not get zinc from local scrap yards, so i put some aluminium heat sink in the solution. and today as i checked the stock pot i am surprised that i have no black powder, its dark gray powder in the bottom and also some particals floating on surface. is it really a problem to use aluminium in the solution in which we already use zinc. as i know al will drop zinc also as zinc chloride. is there any way to remove zinc chloride from black powder! and what is this dark gray percipate! thanks and sorry for bad view of picture!and i dont know why its uploaded from down to upward!


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## Yggdrasil (Jun 27, 2018)

Hi!
I did the same thing and have warned in another thread that it has to be done with care.
In my case I had a solution that was hard to cement with copper, and when I used zink, it plated the container.
The aluminum cemented fast and complete, but I was absent 2 weeks without removing the heatsink, which made the heatsink dissolve completely and form a grey thick sludge, maybe some kind of Aluminum chloride or oxide.
I managed to get most of the PGM-blacks out, but are now treating the sludge with alcohol and isopropanol to lower the viscosity and specific gravity. Then ultrasound to vibrate the particles. This seems to give some progress. Later I will roast it and redissolve in HCl and peroxide before I concentrate and drop it with pure Zink this time.
I believe the error with cementing first time was too dilute solution and not enough strirring.

My general idea still is that dropping with Al may be viable, but one has to be sure to stop it immideatly when it is done, to avoid this grey sludge.
I will test at a later stage some time :wink:


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