# PGMs optimum leach methods



## kjavanb123 (Feb 1, 2011)

All,

The last PGMs recovery I heated the cat in 4HCL:1HNO3 for few hrs and I could fairly get most of the PGMs in short period of time. In my previous recovery, I used HCL:CL method, however without the heating in a sealed container it would take 10 days which seems to be a long time. and 10HCL:1H2O2 is expensive due to H2O2 cost. AR leach also is costly due to removal of nitric on steam bath, so i assume the best methods to recover PGMs from cat would be HCL:CL leach, any advise on this?

Also, I purchased solid chlorine which i presume is CL. can that be used with HCL and 80c heat to produce HCL:CL leach? would that recover most PGMs including Pt and Rh?

Thanks
Kev


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## lazersteve (Feb 1, 2011)

The HCl-Cl method can be sped up by using diluted HCl (15%) and periodic agitation of the ceramic material. I've adopted a method of using a setup similar to my AP double bucket arrangement to allow me to draw the inner bucket with holes in the bottom up to force the solution through the material inside the inner bucket.

Cold helps the solution stay saturated, but heat speeds up the attack of the metals by the solution.

Rh and Pt can be extracted with HCl-Cl. If the Rh is oxidized first it helps the reaction move quicker.

If you set up a series of reactions starting them on different days, you will eventually have a continuous extraction process going on.

Steve


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## kjavanb123 (Feb 3, 2011)

Steve,

I am planning to set up the following plan for my Hcl-Cl leach;

one 5000ml beaker containing 2 honeycombs, with HCl heating at 80c. a small bucket, 2 water pump isolated so Hcl won't effect them, one pumps the warm hcl from beaker to bucket, the other pumps the solution in bucket back the beaker, since the same model pump is being used, the output rate is the same as input, all i do is either add the Chlorine (white powder) to the bucket, or the Whitex into the solution. Now I assume to produce Chlorine gas also would be helpful, how can i produce Cl gas from Cl solid or Whitex? do I just heat it up? I will post pics on Sunday.

Thanks
Kev


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