Nitric and Palladium

[rcarbon]

whats the best method to make Palladium hydroxide from Palladium dissolved in AR,

 

[Lou]

Add NaOH?

 

[rcarbon]

I am trying to make pure Cl free Palladium nitrate. Some times palladium does not completely dissolves in Nitric Acid. If I dissolve it in AR then convert to Palladium Hydroxide, and then completely wash it, and then add little nitric acid,
will i be getting back, Cl free pure palladium nitrate ?

Please explain. Also please do let me know any other method to get rid of Cl.

Thanks

 

[Geo]

You can drive off chlorine with heat. I may be mistaken but Paladium will dissolve in hot nitric acid.

 

[rcarbon]

In past I have tried several times, but every time Pd supplied by various or same supplier behaves differently.

Some times it simply melts in hot Nitric acid like butter in just 2 hours and sometime it dissolves on 10 - 15 % in same amount of acid under same conditions , even in 48 hours

 

[Smack]

It must have been alloyed then. Same material and conditions, same results, different material same conditions, different results.

 

[Harold_V]

Some times it simply melts in hot Nitric acid

I find it strange that you can heat nitric acid hot enough to **melt** palladium.

Harold

 

[rcarbon]

it doesn't has to be hot enough, I have experienced this at temp of of about 75 - 85 C

 

[butcher]

rcarbon,

You can only melt palladium metal with very high heat, nitric acid would not survive that kind of heat.
You can dissolve palladium in nitric acid, but no matter how hot you get it, you will not melt palladium in nitric acid.


You are using the wrong words to describe what you mean to say, you cannot melt palladium in nitric acid.
This makes it hard for others to understand what your asking or talking about.

Using the correct terms or words will help others understand you better, and does not lead to as much confusion as to what is being discussed, when we use the correct terminology in our discussions, it makes what we say, easier for others to understand what we are saying, it can also help us get better answer to our questions, we all need to try and learn the correct terms to use in our discussions, not only for others but for ourselves.

Spend some time to find the correct word or term, this will help you, and us on the forum, to get a better understanding.

 

[kurtak]

it doesn't has to be hot enough, I have experienced this at temp of of about 75 - 85 C

I think you missed Harold's point completely - he finds it strange that you can heat nitric acid hot enough to "melt" palladium --- because metals are NOT "melted" in acid - they are "dissolved" in acid

The bigger point being made here - & a big part of the reason you are not getting a lot of help with what you are trying to do is that as a "new member" you have not yet taken the advise given to all new members which is to take the time to read Hokes book & read it until you understand it - then take more time to do research here on the forum & do so until you understand what is being done in the different processes --- we ask new members to do this so they can get at least a basic understanding about this & the reason for that is so that when you start asking questions you do it in away that is talking on the same page as the rest of us :!:

Right now everything you are doing is WRONG --- the way you are processing your metal is wrong & the words you use to ask your questions are wrong --- & that's because you have not yet done your "home work" (research & study) --- we will not help you because we can not help you until you do your home work & get on the same page - its that simple

Here are two links you NEED to read - the first one drives home Harold's point - the second one will help you get headed in the right direction for doing your home work including providing a free down load of Hokes book

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=33&t=19074
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=33&t=21374

Kurt

 

[rcarbon]

I do apologize for my wordings

 

[4metals]

I find it strange that you can heat nitric acid hot enough to **melt** palladium.

Just a short refining story to show you what can happen by using the wrong term.

Back in the late '80's I owned a refinery and one of the services we provided was chemical stone removal. One day while I was out a client came in with over 200 ounces of gold jewelry scrap for chemical stone removal. If I was in the office that day it would not have been a problem because I was aware that people from India refer to digesting gold in acid as "melting".

The secretary wrote up the receipt as a melt because that is what the customer said. He signed the receipt and left the job.

The job was placed on the incoming melt shelves and one of the melt shop staff melted it, no biggie, it melted fine and made a nice bar. Well needless to say, the customer was not happy with the result. After his attempt to sue me for ruining a gadzillion dollars worth of diamonds I only escaped financial ruin because he signed the receipt and the receipt said melt.

He didn't mean melt, but it is quite possible that in India that is what it is commonly called. But he was doing business in the US, and business is conducted in English. (At least my business was conducted in English!) That was the way the judge put it.

Ironically we are all participating in a forum that is conducted in English, that is why we have to be careful to choose the right wording.

Fortunately Mr Carbon's mistake will not cost him any values but I give this example to show why Harold will respond as he does. He is really trying to save our members from unnecessary problems.

 

[Lou]

If you seek it to be chloride free, you can either titrate with AgNO3 and accept Pd losses on the AgCl; reflux the mixture with nitric acid to distill off Cl- as chlorine; not use chlorides in your process and buy Pd black that dissolves well in HNO3.


Alternatively, you can make the hydroxide and dialyze it in conductivity water to remove chlorides.

Lou