# Ceramic Catalytic converter smelting



## kjavanb123 (Sep 27, 2019)

Hi

After a long due, I finally had the time to try smelting a ceramic cat converter.



I crushed then milled the sample cat which weighs 750 grams.

Took a 13.28 gram fine ceramic cat and placed it in a melting dish.



For process I used 168.6825 grams (5.950 oz) lead, which 18.8811 grams (0.666 oz) silver shots were added while it was molten.

The reason oz was used so once this process is finished any traces of PGMs collected by lead silver alloy from the cat can be detected.

I placed the lead-silver alloy on top of fine ceramic cats and melted it, my plan was to melt the lead alloy as it pours down the dish fine cat materials are coming to the surface and during this transition micro sized PGMs are collected.

As lead silver alloy melted at first nothing showed on the surface but few seconds later tiny pieces of fine ceramic cats came to surface of molten lead.

I used a stainless steel rod to stir the fine cat at beneth the molten lead as they came to the surface.

So I poured the molten lead silver into a mold, most of it poured there was a piece left in the dish as fine cats were stuck to it. It can be seen in the following;



This was what was left after I removed the molten lead.



Next I am going to cupel the lead bead, and weig the silver button also dissolve it to see if and what PGMs did it collect from ceramic cats.

Eventuallly I will take the fine to the shop where we will smelt them using our stationary furnaces which is basically working like a large melting dish.

I will also test small sample of this cat smelting with sodium bisulfate as it was briefly discussed by a member.

Best regards
KJ


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## kjavanb123 (Oct 1, 2019)

Here is some updates on my adventure smelting ceramic cats.

Got a silver alloy after cupelation of lead, dissolved it in nitric acid, it seems very small Pd in solution and what seems like Rh powder.




And possible Rh powder



These Pd and Rh came from just three teaspoon of fine cats.

I will drop the Pd and dissolve the possible Rh using hot concentrated acid to confirm it is Rh.

Keep you posted


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## kjavanb123 (Oct 3, 2019)

New updates

I cemented the black powder from yellow solution in previous post by zinc. 



Since the content of silver used in smelting exceeded 75% and PGM content was only trace, any Platinum would have been dissolved in nitric acid along Palladium.

So I dissolved the black powder in warm dilute nitric acid, got a very pale yellow solution and grayish powder which settled at the bottom.

Pd nitrate solution



Garyish residue (possible Rhodium?)



That gray residue in filter paper



More pictures in next post


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## kjavanb123 (Oct 3, 2019)

I rinsed the gray powder into a beaker and decanted its water, added concentrated sulfuric acid, I didnt see any immidate reaction so I let it simmer for half and hour, I am guessing dissolving Rhodium in sulfuric acid takes a lot longer. Please advise.

For Palladium nitrate solution I used DMG, this is as soon as it was added to Palladium nitrate solution.



The DMG salts seem like redissolving back,



Filtered the DMG salt which by the end of filtering only small amout remained. Here is the black powder



So far this is the result from lead smelting only 3 teaspoon of fine ceramic catalytic converter.

It seems I was able to recover Palladium and possibly Rhodium.

Will continue smelting the rest of the fine powder and keep you posted.

Thanks
KJ


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## Lino1406 (Oct 5, 2019)

The amount of PM's expected from 1 converter is very few grams. Hence you used too much lead and silver and this is not a worthwhile method


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## kjavanb123 (Oct 6, 2019)

Hi

The purpose of the primilary test was to see if I can recover palladium and rhodium. 

The charge I used was only 3 teaspoon and expected PGM from that much is very little.

I am smelting all 750 gram fine powder this week using our bigge furnaces and post pics.

I like to try lead smelting cats to see if our method here work or not.

Thanks
KJ


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## kjavanb123 (Oct 6, 2019)

Hi,

I took a 4 gram sample from the fine ceramic catalytic converter, and heated in concetrated sulfuric acid for an hour. Result is a very pale yellow solution as it can be seen here.

4 gram sample ceramic cats



Heated in concetrated sulfuric acid



Comparison between just concetrated sulfuric acid color on the left, and sulfuric acid heated with ceramic cats on the right.



To be sure solution on the right contains rhodium, I need to pour it to large volume water, then test it with stannous chloride, which is coming up next.

I am also waiting for my cryolite to arrive, so I can give the whole thing is a smelting.

Thanks
KJ


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## kjavanb123 (Dec 13, 2019)

Hi

Took a 50 gram sample of milled cat from this thread. Mixed it well it with 50 grams of cryolite. Smelted it with lead silver.

Got 0.21 grams of Platinum black, 0.02 grams of Palladium black, and what it seems 0.01 Rhodium, that makes PGM content for this specific ceramic cat to be 3.1 grams of Pt, 0.3 gram of Pd, and 0.15 gram of Rh.

I tried to smelt the rest of 700 grams, but due to some accidents it was a failure.

Here are some photos;

Silver shots from cupelation



Rhodium powder from dissolving silver shots in nitric acid



Palladium nitrate, and Platinum black not soluble in nitric at the bottom.



Palladium black percipitated from nitrate solution



And finally this is the slag, which seemed to have dissolved all the fine ceramics.



I have another 388-gram ceramic cat, different car, which I will smelt and post result hopefully without any accidents.

Best regards
KJ


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## kjavanb123 (Jan 23, 2020)

Hi

I knew about using lead cupeling, it can melt and purify silver, gold.

This was my first try lead cupeling with palladium black powder, which resulted in a bead weighs so small that my scale doesnt show.

Under the lope it shows the shining palladium metal.



This proves to be an efficent and loss free way of melting small or large quantity palladium.

Thanks


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## Lino1406 (Jan 23, 2020)

Is reductive atmosphere to avoid Pd blackening can be spared in this situation?


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## kjavanb123 (Jan 24, 2020)

I dont see any black spot under the lope, but I know for a fact cupeling silver powder will have some losses.


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## kjavanb123 (Feb 3, 2020)

Hi

I am processing a batch of old telephone switchboard. It was positive for palladium.

I had a copper nickel palladium nitrate solution which I used the standard DMG solution to drop Pd.

It percipitated as green color first but after filtering and washing it becomes different color than yellow.

Here is a picture



In an acidic nitrate solution which is positive for palladium, does DMG percipitate other metals? Besides Pd?


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## Lino1406 (Feb 3, 2020)

My experience is that rhodium, silver, platinum even gold will follow palladium in precipitate if present. Also base metals from solution and adjacent precipitates should be deleted to avoid their joining. Red tint may be of course nickel but also iron


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## kjavanb123 (Feb 3, 2020)

Thanks Lino

I have always get yellow DMG Pd salt when using it to drop from nitrate solution.

This is very first time even after washing I get this pink purpule color salt.

I cemented this DMG salt with zinc powder and it produced grayish residue which easily dissolved in nitric acid and solution was clear.

Added hcl to that solution and a white yellow cloud formed which resembled silver chloride however it didnt turn purple under the light.

Nickel will percipitate using DMG only in allaline condition, based on what I have learned here.

Thanks and regards
Kj


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## Lino1406 (Feb 3, 2020)

"easily dissolved in nitric acid and solution was clear." At that point I would check for silver (or lead) with K2Cr2O7. Wash the sediment obtained with HCl and check liquid for Pd


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## kjavanb123 (Feb 4, 2020)

All

I smelted a connector from the telephone switchboard and got 0.37 gram of palladium.

Here are the pictures



Here is the close up shot from back



Here is the front



There are over 100 pieces of slots to be processed, it seems that smelting is the only way to process them.

Stay tune for result and pics of the switchboard

CORRECTION
After dissolving the above bead in warm dilute nitric acid, I got silver nitrate only so this was only silver.

It is unusual since the card I tested with DMG had yellow Pd DMG salt so connection would be the same material, but that is not the case

Here is the telephone switchboard and the card that was positive for Pd.


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## kjavanb123 (Feb 6, 2020)

I dissolved the slots in previous post, dropped the silver as chloride, and solution with stanous chloride test shows yellow as seen in pictures below,

My intreption of stannous result is Platinum, but never seen a silver alloyed or plated with Platinum.

Please advise






Please note the solution is blue but stannous turns that into yellow as seen.

If is Pt, adding DMG would precipitate Pt also based on my understanding.

Here is a drop of solution before adding stannous chloride test



This is stannous chloride solution addition


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## Lino1406 (Feb 6, 2020)

No suspicion for copper in addition?


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## kjavanb123 (Feb 6, 2020)

Hi Lino

So you mean does solution turn yellow if copper is presented? The majority of solution is copper.


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## snoman701 (Feb 6, 2020)

How did you smelt it? In lead?




Sent from my iPhone using Tapatalk


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## kjavanb123 (Feb 6, 2020)

snoman701 said:


> How did you smelt it? In lead?
> 
> 
> 
> ...



Hi

Yes pins were smelted using lead. First pins werer melted in crucible without any flux.

Once molten 100 gram lead was added and waited for lead to completely dissolve molten pins.

Lead bead was cupled in Portland cement, ans resulted in the silver bead. 

Silver bead dissolved in nitric acid and solution eventhough was orange in color but was negative for Pt or Pd.


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## Lino1406 (Feb 6, 2020)

Stannous chloride can delete color. Yellow can come from many sources


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## kjavanb123 (Mar 10, 2020)

Per my last post, I smelted wires in the back of telephone boards using lead and copper dore.

After dissolving the copper from above, percipitated and melted 13 grams of silver from the wires.

I used the following system to agitate copper nitrate solution while hanging a copper rod to plate any PGMs those wires might have that causes the color change with stannous chloride.

There is a water pump on the left pumping and pushing the copper solution to the bucket while I hung the copper rod on the left.

Copper rod is small and hanging in the middle of bucket.

It has been running for few minutes now, I will give it 24 hours and see if it precipitate any black powder.

This is my first try using copper to plate out PGMs from a nitrate solution.




Best regards
KJ


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## kjavanb123 (Mar 12, 2020)

Hi

I had a crushed (not puvlerized) ceramic catalytic converter, I placed them in a stainless steel pot.

Filled it with dilute nitric acid, used a water pump to circulate the nitric acid.

I put the whole thing on a mini gas stove, and heat it.

Here is the pic of the system



I let it run for 2 hours and checked the solution with stannous chloride testing solution, swap on the left was stannous result half and hour into stirring and heating, then the right one is at the 2 hour mark.




I rinsed the solution was brown, added water to the cats started the pump and heat and let it run for another 30 minutes. 

Rinsed the yellow color solution, added more water and ran the system, solution was clear andand stannous was negative.

Next day, I collected 500 ml of the rinse and main solution, as seen in following, if the volor doesnt look like palladium nitrte solution then I dont know what will,



Here is the bizzare thing, I checked the 500 ml solution with stannous and got nothing no color change nothing, thinking mabye my testing solution is bad, so I made another one but still no sign of Pd ???

I tried adding DMG, got a white color percipitation but as I was filtering it dissolved into the solution.

So I really cant think of why is this??? Main solution was 3.5 liter and rinses 6.5 liters


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## anachronism (Mar 12, 2020)

I don't understand what you mean by rinse. 

The first brown solution you rinsed away?


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## kjavanb123 (Mar 12, 2020)

anachronism said:


> I don't understand what you mean by rinse.
> 
> The first brown solution you rinsed away?



Hi

Nitric solution after 2 hours decanted, water was added boiled and stirred then decanted to the previous solution.

The solution in the beaker was from above


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## anachronism (Mar 12, 2020)

That's an awful lot of solutions for one small dissolve.


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## kjavanb123 (Mar 14, 2020)

I was trying to leach cermaic cats using a water pump to stir.

After the Pd failure to drop, I leached the cats using concentrated sulfuric acid for 2 hours.

I used the same stainless steel pot, let the solution stir and put it on low heat.

Here is what the cats and sulfuric solution look like the next day;



This is the solution from above diluted with water to filter,



This is Rh black which was percipitated from above solution using zinc powder, it is very fine compare to Pd or Pt drops,



I made a mistake and didnt remove the water pump after the leaching finished, so next morning that part in the solution was dissolved.

Once I filter it I will drop the Rh black


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## kjavanb123 (Apr 28, 2020)

Hi

Jason from Mt Baker mining metals just posted the following that he tries smelting cats.

https://youtu.be/cmnY41jqPGI


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