# Sulfuric Acid??



## jjohio (Feb 26, 2012)

In time, wont sulfuric acid completely eat a ceramic honeycomb from a converter and leave platinum behind??


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## jjohio (Feb 26, 2012)

I should of stated sulfuric Acid would DISSOLVE the honeycomb...not eat it!! Anybody have experience with this and any detail??


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## jjohio (Feb 26, 2012)

27 views, but no comments???


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## lazersteve (Feb 26, 2012)

I have seen a video on Modern Marvels where the refinery used hot sulfuric acid to digest the substrate out of the catalyst. The catalyst on the program was not from cars, it was from some sort of chemical reaction tower.

The real main problems with using hot sulfuric acid are two fold:

1) Hot sulfuric acid is extremely dangerous and unforgiving when it comes to mistakes and accidents. If you are not 100% set up for working with it, you can get badly hurt. I don't recommend this process to any hobbyist.

2) If you have success at dissolving the substrate, you will end up with a lot of waste liquids that must be properly disposed of. 

There are many methods posted on the forum for removing PGMS from auto catalyst. You may want to do some research using the search function to see what others are using.

If you are a visual learner, you can buy the Fundamentals of Platinum and Palladium DVD from my web store http://goldrecovery.us/pricing.asp . The DVD demonstrates a relatively safe method of recoverying and refining the Platinum and Palladium from automotive cats.

Dry PGM salts are dangerous in themselves to handle and be around. They can cause permanent allergies and breathing problems. Proper safety and storage is important to your personal safety. Study all the materials and processes before you begin working with any of these compounds and metals.

Several years ago I have also posted an article on using diluted sulfuric acid to dissolve PGMs from catalytic converter honeycombs. I have tested the process and had mixed success. You should be able to find it using the search function.

Take care and be safe,

Steve


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## jjohio (Feb 26, 2012)

Thanks Steve!!


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## Lou (Feb 27, 2012)

Hot caustic works better than sulfuric acid at dissolving the substrate.

That show that Steve references was for very heavily loaded industrial catalyst (think of what goes on the afterburner at a steelmill or from a petrochem cracker), not the autocatalyst that most know.


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## Oz (Feb 27, 2012)

Hot caustic is just as hazardous as hot sulfuric acid FYI for those that did not know.


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## jjohio (Feb 27, 2012)

sodium Hydroxide?? Is that what your referring to Lou?...Would it be hard to get platinum out using this?


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## butcher (Feb 28, 2012)

Caustic soda is another name for sodium hydroxide.

this is just a dangerous Idea.

Take Lazersteves advice, use acids to leach the valuable metals, trying to dissolve the ceramic substrate would be too dangerous and more trouble in my opinion.


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## Lou (Feb 29, 2012)

Better advice,


Don't bother leaching catalytic converters for profit unless you're getting them for a phenomenal discount.


As far as caustic goes--most of that's done in sealed stainless vessels to produce aluminate and done with high value industrial catalysts. Either that or it gets put into a 30,000 lb rotary furnace with copper. Seen it done both ways.


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