# Reduction of precious metals using mercurous halides



## Beetle Juice (Jul 7, 2013)

Hi there forum members, as this is my first forum post I will keep this brief but firstly I must say what a great learning resource on pgm chemistry this forum is. Secondly I would like to find out if anyone has come across the use of mercurous chlorides as an alternative to hydrazine reduction for chlorinated solutions of precious metals. I have found a few old papers and patents for this process;

http://www.google.com/patents/US2044366?pg=PA1&dq=pierson+mercurous&hl=en&sa=X&ei=U7DZUaXvOpLA7AaAooHoCA&ved=0CEAQ6AEwAQ#v=onepage&q=pierson%20mercurous&f=false

If someone could answer the following questions I would much apperciate it;
1.Has anyone ever done this?
2.Would it be possible to extract rhodium and iridium.
3. Would it be possible to dissolve the filtered mercurous chloride pgm precipate in dilute acid as such the mercury is removed and pgm blacks remain. 
4. If it was contained within a closed system would it be possible to avoid any mercury losses


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## Lou (Jul 8, 2013)

This is only used in some ISO assay procedures for PGMs.


Due to health and safety issues, this is not a production-practical method. 


Hydrazine can be destroyed in solution while Hg ions need to be scrubbed with special resins.


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## Lino1406 (Jul 8, 2013)

To introduce mercury in your system is like
introducing illness in healthy bed - you'll never get away with it


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## Harold_V (Jul 9, 2013)

Lino1406 said:


> To introduce mercury in your system is like
> introducing illness in healthy bed - you'll never get away with it


That would certainly be my take on things. 

Harold


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