# Purifying Pt



## kjavanb123 (Apr 12, 2011)

I got the red Pt salt, can it be purfied using the same method as of Pd? by dissolving in ammonia?

thanks
Kev


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## patnor1011 (Apr 12, 2011)

Kev, I follow your quest of recycling cats and getting a lot of information from what you encounter on your path in reclaiming platinum group metals. 
If I may suggest - you will be much better served if you try to keep everything in one two threads where you can go back for references and whole process can be seen instead of opening new threads with every problem you are trying to solve. You are then time and again asked the same questions about what was source, what process did you apply and so on.


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## Lou (Apr 12, 2011)

What red Pt salt do you have? What do you think you have?


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## Barren Realms 007 (Apr 12, 2011)

Lou said:


> What red Pt salt do you have? What do you think you have?



8) I love the way you teach.


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## kjavanb123 (Apr 13, 2011)

Lou,

Stannous test shows Pt sign, I have incinerated it and it is ready for melting. I was curios since Steve's Pt were mostly yellow, mine is like the following,



and here is stannous result



Does ammonium chloride only drop the Pt from the solution or other sister metals can be dropped?

Thanks
Kev


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## Lou (Apr 13, 2011)

Ammonium chloride is indiscriminate--it'll drop Rh, Ir, etc. Much depends on oxidation state (hence Pd being separated by using chlorate).

Pure ammonium hexachloroplatinate is a yellow sparingly soluble salt.


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## lazersteve (Apr 13, 2011)

If nitric is present the Pd and Pt can also co-precipitate with ammonium chloride.

Dissolve a sample of your powder in HCl, add DMG, filter off the dark yellow precipitate, and test the filtered solution with stannous chloride for Pt.

Steve


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## kjavanb123 (Apr 20, 2011)

I got 5grams of PGM black powder from zinc cement process, then added 10ml of HCL heat it and add 1ml of HNO3 to it, it dissolved all the black powder, in a separate beaker i prepared 1.5ml x 5 = 7.5 almost 10ml of water with 4 grams of ammonium chloride, nothing happened. Yet it is positive for Pt.?? isn't 1.5ml of saturated ammonium chloride for every grams of Pt/Pd? The only thing i can think of is i let the ammonium chloride solution to cool off before i poured in Pt solution to it. Here is the pic show 

1. mixed black powder at get go, combined weight 57.37g - 50.16g beaker weight = 7.21 g 
i can't post any pics, it keeps asking for the textual confimration, and goes back to the post page and it's a loop..


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## lazersteve (Apr 21, 2011)

You are using the wrong units for your ammonium chloride addition. It's 1.5 grams of *ammonium chloride (NH4Cl)* per gram of dissolved Pt/Pd, not 1.5 mL.  

You can easily make a concentrated solution of ammonium chloride via:

37.2 g NH4Cl + 100 mL Distilled H2O

This will require a little heat (hot water bath) to get all of the salt into solution since the reaction is endothermic (absorbs heat= gets cold), then allow it to cool to room temperature before use.

Each mL of this solution is equal to 0.372 g of ammonium chloride.

For the mathematically challenged:

1.5 g / 0.372 g/mL =~ 4 mL of concentrated NH4Cl solution, prepared as listed above, per gram of Pd/Pt in solution. 

Lou has actually suggested 1.1 g of saturated NH4Cl per gram of Pt/Pd so this works out to:

1.3 g / 0.372 g/mL =~ 3.5 mL of conc. NH4Cl solution per gram of Pt/Pd in solution.

I've had excellent results adding the saturated solution of ammonium chloride directly to my Pt solutions when they are sufficiently concentrated, but you can also add the Pt solution to the NH4Cl if you like. The yellow salt forms instantly in most cases.

Here's a post with some photos:

Pt Precipitation

I'll video this process soon and post it for you to see.

I recommend following Lou's simple method of separating small amounts of the mixed PGM powders as detailed here:

Separating Mixed PGM Powders

Steve


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## kjavanb123 (Apr 23, 2011)

Steve,

Thanks for ur extensive explaination of these processes. I learned from my last leaching that once i used water in my AR it could only get Pd, vs when i use hcl:hno3 it would extract Pt / Pd / rh while it's hot.

Here are some snapshots of the process. BTW, is something wrong with uploading function? it let me select the picture but keep repeating asking the same confirmation and no link shows. 



Kev


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