Sciencemadness Discussion Board

Platinum Recovery

kjavanb123 - 30-12-2010 at 06:59

All,

This is my first post and very first time here. I have heated an automobile catalysts in concentrated Aqua Regia for 5hrs and stannous chloride tested positive for Pt. Here is the picture of the solution after 10mins of boiling in AR.

concentrated AR 15 minutes into boiling.jpg - 232kB

Then I tested it with stannous chloride and here is the result

stannous test result 2.jpg - 198kB

The same solution after being left outside over night, it changed color as you can see here.

Solution at room temp.jpg - 132kB

Just to test, 20ml of the solution is being evaporated on steam bath to get rid of NOxx and added 20ml of HCl after it turned to syrup. This step repeated 2 times

solution evporating the nitric started.jpg - 138kB

Solution after being on steam bath for few mins

solution 10mins into evporating the nitric.jpg - 156kB

After hydration the syrup with HCL I added half of its volume water.
solution diluted with water.jpg - 164kB

I added ammonium chlorate to dilute solution while being on steam bath, and all i got was some small amoutn of white fine powder at the bottom at the picture
Orange powder or just ammonium chloride.jpg - 66kB

Now can someone tell me what I do wrong here? I mean how can i get the yellow powder that is pt?

Thanks
Kev

hissingnoise - 30-12-2010 at 07:36

Your solution is likely to contain several different metal ions and separation will almost certainly be difficult.
Chloroplatinic acid, BTW, is readily reduced by strong heating.

http://herkules.oulu.fi/isbn9514269543/html/x382.html


Fleaker - 2-1-2011 at 11:58

You would do well to avoid heating chloroplatinic acid if you want to avoid metal losses.

See my thread here:

http://www.sciencemadness.org/whisper/viewthread.php?tid=972...

[Edited on 2-1-2011 by Fleaker]