Precipitant for palladium
- Thread starter Renaldas
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jimdoc
Well-known member
What country are you in? Somebody may be able to help you find a source if they know where you are.
Jim
Jim
jimdoc said:
Lithuania, European Union. There are ways of getting sodium chlorate, our chemical shops can make an order of several hundred kilos or even a tonn, no small quantities ... So I thought, maybe there are other precipitants for palladium ...
jimdoc
Well-known member
Maybe you could make your own?
http://webpages.charter.net/dawill/tmoranwms/Chem_Chlorate.html
Jim
http://webpages.charter.net/dawill/tmoranwms/Chem_Chlorate.html
Jim
Excellent post Jim,
I have been making small amounts of chlorate a little differently.
This process seems to be a little more advanced with better results than my own (ice bath) has produced.
I think I will try it.
I will let you know what I come up with.
Is this the process you use?
Mark
I have been making small amounts of chlorate a little differently.
This process seems to be a little more advanced with better results than my own (ice bath) has produced.
I think I will try it.
I will let you know what I come up with.
Is this the process you use?
Mark
Irons
Well-known member
Renaldas said:
Any source of Cl2 is a substitute for Chlorate. If you add household chlorine bleach to HCl, it makes a good Chlorine generator.
SO2 will precipitate Pd.
Dry bleach, calcium hypochlorite, will also work. Add it in very small increments to the concentrated HCl solution of Pd and ammonium chloride.
Steve
Steve
jimdoc
Well-known member
Mark,
I bought what I am using now, but when I have to make, it I will.
It's good to keep info like this for when things get tough to find.
Jim
I bought what I am using now, but when I have to make, it I will.
It's good to keep info like this for when things get tough to find.
Jim
Mark,
Calcium hypochlorite works best when the solution contains HCl.
The HCl and hypochlorite forms chlorine gas in situ.
The reason you use dry calcium hypochlorite is to keep the solution concentrated. Liquid bleach (e.g.: Clorox) is less than 5% hypochlorite and the rest is water which dilutes the solution.
As you know PGMs don't precipitate well if at all from dilute solutions in most cases.
Steve
Calcium hypochlorite works best when the solution contains HCl.
The HCl and hypochlorite forms chlorine gas in situ.
The reason you use dry calcium hypochlorite is to keep the solution concentrated. Liquid bleach (e.g.: Clorox) is less than 5% hypochlorite and the rest is water which dilutes the solution.
As you know PGMs don't precipitate well if at all from dilute solutions in most cases.
Steve
Mark,
If there is enough left over free chlorine from the palladium dissolution, the solution is the right temperature, the right concentration, and you add ammonium chloride, the palladium will precipitate as palladium ammonium chloride. If platinum is present under the right condition it will co-precipitate with the Pd also.
If you used clorox to put the Pd into solution then you most likely don't have a concentrated solution. This is yet another reason why I using zinc to precipitate the mixed PGMs out of HCl-Cl solutions before trying to separate them. If you try to concentrate the solution buy evaporation you'll get a lot of salt formation that will muck things up.
Once you've used zinc to precipitate out the black mixed PGM powder then you should use the AR process to do the final separations. Using AR directly on bulk low percentage yield scrap is more costly than HCl-Cl and zinc.
Steve
If there is enough left over free chlorine from the palladium dissolution, the solution is the right temperature, the right concentration, and you add ammonium chloride, the palladium will precipitate as palladium ammonium chloride. If platinum is present under the right condition it will co-precipitate with the Pd also.
If you used clorox to put the Pd into solution then you most likely don't have a concentrated solution. This is yet another reason why I using zinc to precipitate the mixed PGMs out of HCl-Cl solutions before trying to separate them. If you try to concentrate the solution buy evaporation you'll get a lot of salt formation that will muck things up.
Once you've used zinc to precipitate out the black mixed PGM powder then you should use the AR process to do the final separations. Using AR directly on bulk low percentage yield scrap is more costly than HCl-Cl and zinc.
Steve
Yes, of course after complete denoxxing, but you know that.
There is a post from one of the members here that I've been trying to find where I suggested this and it worked for him.
Steve
There is a post from one of the members here that I've been trying to find where I suggested this and it worked for him.
Steve
Mark, PM's sent.
lazersteve said:
Thank you for information!
Can you say me, please, either platinum and palladium precipitate with NH4Cl both from concentrated AR solution after neutralizing nitric acid, or only platinum. I added a little NH4Cl to my AR solution, and orange cryslals formed. What is it?
Renaldas said:
Most likely Platinum. The purer the precipitate the more yellow the color.
Steve
