# Hot AR on cats



## madelyn (Jun 3, 2013)

I want to try something but first need some professional advise from the forum. If I use a silicon heater on a 20 litre plastic drum with ar inside and heat it up to 60 to 80degrees with catalytic converters on the inside and agitation. Wil it be able to dissolve all the metals even the rhodium within a 24 time limit? Also can I use urea to suppresse the nitric acid and precipitate with zinc?


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## squarecoinman (Jun 4, 2013)

madelyn said:


> I want to try something but first need some professional advise from the forum. If I use a silicon heater on a 20 litre plastic drum with ar inside and heat it up to 60 to 80degrees with catalytic converters on the inside and agitation. Wil it be able to dissolve all the metals even the rhodium within a 24 time limit? Also can I use urea to suppresse the nitric acid and precipitate with zinc?




Hi Madelyn you need to give a little better information.

I have plastic drums that with out problems can be heated to 80 degrees Celsius , i also have a few in the kitchen that would not be happy being heated to 80 degrees Celsius 
Since you are in Namibia i assume you mean Celsius .
The answer is No AR will not dissolve all metal within a 24 Hour time limit , and yes the Rhodium is the problem. Rhodium dissolves best in hot sulfuric acid.

I don´t Like Urea and would not use it , but would denox in another way, evaporation 

scm


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## madelyn (Jun 4, 2013)

This would be PVC plastic drums and yes it is celsius. Can you explain why the rhodium wouldn't dissolve or would it take longer?


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## kjt124 (Jun 4, 2013)

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=37&t=14894

Check this thread. Rhodium is not easy for the backyard chemist. I know I would have little ability to try any of these methods, but AR will not work. Even with the HCl, bleach, and peroxide method under ideal circumstances you are looking at (if I remember correctly) 60-70% theoretical dissolution. I do not know what the time frame was in the paper that info came out of or what the paper was (perhaps by Gilchrist, but don't hold me to it).  It was an old paper on wet methods specifically aimed at automotive catalytic converters.

As far as the more exotic metals, you would be well served to do some studying on what Lou has to say about them. He can manipulate Rhodium, etc. like me making a jug of iced tea.

Good luck,
Kevin


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## canedane (Jun 4, 2013)

madelyn said:


> This would be PVC plastic drums and yes it is celsius. Can you explain why the rhodium wouldn't dissolve or would it take longer?


Are you sure it is pvc? Acid resist plastic drums should normally be pe or pehd, you can read it in the bottom of the drum, please be very carefull it is very dangerus if the drum leak.
Henrik


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## squarecoinman (Jun 4, 2013)

canedane said:


> madelyn said:
> 
> 
> > This would be PVC plastic drums and yes it is celsius. Can you explain why the rhodium wouldn't dissolve or would it take longer?
> ...



Madelyn I would not put 80 degrees AR ( with possible sulfuric for the rhodium ) in PVC 

scm


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## madelyn (Jun 4, 2013)

Thanks! All of you for the great opinion on this,it is exactly what I needed to hear. It was just a theoratical memory of what I thought could be done but I won't try it now that I know what all the cons are.


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