palladium sponge calcination temperature ?

[jsyouu]

I study spent catalyst recover and create used Pd.

A yellow salt was formed, which is the final step in the Pd recovery process.

At what temperature should yellow salt be calcined to make Pd concentrate sponge?

When I calcination it at 310℃ for 5 hours, it became black palladium powder, but it was not in the form of a palladium sponge.

Should I calcination at a temperature over 800℃ instead of 310℃?


I have another question.

Is it better to use hydrogen peroxide instead of nitric acid to dissolve precious metals?

How much ammonia should be added when recovering Pd?

 

[Yggdrasil]

사용한 촉매에서 Pd를 회수하고 싶습니다.
팔라 축 회수 공정의 마지막 단계인 노란색 염이 형성되었습니다.
팔라듐 스폰지를 만들기 위해 노란색 소금을 어느 온도에서 하소해야 합니까?

I can not help you unless you post in English and I expect that is true for most members.
Salts of the Platinum Group Metals are very toxic so you have to be very careful.

Here is our study list:
We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: Screen Readable Copy of Hoke's Book
2. Then read the safety section of the forum: Safety
3. And then read about "Dealing with waste" in the forum: Dealing with Waste

Suggested reading: The Library

 

[jsyouu]

I can not help you unless you post in English and I expect that is true for most members.
Salts of the Platinum Group Metals are very toxic so you have to be very careful.

Here is our study list:
We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: Screen Readable Copy of Hoke's Book
2. Then read the safety section of the forum: Safety
3. And then read about "Dealing with waste" in the forum: Dealing with Waste

Suggested reading: The Library

I wrote again in English.

 

[Yggdrasil]

I study spent catalyst recover and create used Pd.

A yellow salt was formed, which is the final step in the Pd recovery process.

At what temperature should yellow salt be calcined to make Pd concentrate sponge?

When I calcination it at 310℃ for 5 hours, it became black palladium powder, but it was not in the form of a palladium sponge.

Should I calcination at a temperature over 800℃ instead of 310℃?


I have another question.

Is it better to use hydrogen peroxide instead of nitric acid to dissolve precious metals?

How much ammonia should be added when recovering Pd?

The important thing is to not have the temperature higher than that the smoke which comes from the Salt is white.
If it has any other color than white you are loosing Pd.
But it seems the higher the temperature the fluffier the powder, this will be a balancing act between loosing Pd and bigger grains.
You can also use formate reduction and formic acid which removes the risk of loosing the Pd, but produces a dense powder.
What is wrong with Pd powder vs sponge?
Do you need it to be in sponge form?

HCl/Peroxide works well with PGMs as long as they are in fine powder.
For Pd Nitric is sufficient.

 

[Lino1406]

I study spent catalyst recover and create used Pd.

A yellow salt was formed, which is the final step in the Pd recovery process.

At what temperature should yellow salt be calcined to make Pd concentrate sponge?

When I calcination it at 310℃ for 5 hours, it became black palladium powder, but it was not in the form of a palladium sponge.

Should I calcination at a temperature over 800℃ instead of 310℃?


I have another question.

Is it better to use hydrogen peroxide instead of nitric acid to dissolve precious metals?

How much ammonia should be added when recovering Pd?

According to Pd++ + 2NH3 = Pd(NH3)2++
106.7 g palladium consume 34 g NH3 for palladium-ammonium complex. Normally a big excess is used since the beginning is highly acidic

 

[jsyouu]

The important thing is to not have the temperature higher than that the smoke which comes from the Salt is white.
If it has any other color than white you are loosing Pd.
But it seems the higher the temperature the fluffier the powder, this will be a balancing act between loosing Pd and bigger grains.
You can also use formate reduction and formic acid which removes the risk of loosing the Pd, but produces a dense powder.
What is wrong with Pd powder vs sponge?
Do you need it to be in sponge form?

HCl/Peroxide works well with PGMs as long as they are in fine powder.
For Pd Nitric is sufficient.

I know that high purity Pd sponge (black powder) is need to make PdCl2 catalyst.
I want to make a catalyst with high purity Pd sponge.
Do you know about the purity analysis method of the Pd sponge?
I know that ICP is difficult to analyze with high purity.
Is it right to analyze by XRF?

 

[Yggdrasil]

I know that high purity Pd sponge (black powder) is need to make PdCl2 catalyst.
I want to make a catalyst with high purity Pd sponge.
Do you know about the purity analysis method of the Pd sponge?
I know that ICP is difficult to analyze with high purity.
Is it right to analyze by XRF?

I'm not sure about the precision of XRF on powders.
It is good on metal buttons.

 

[Lino1406]

XRF will tell you what you have qualitatively. In case you have pure PdCl2 or pure PdO it will read 100% Pd

 

[jsyouu]

I'm not sure about the precision of XRF on powders.
It is good on metal buttons.

XRF will tell you what you have qualitatively. In case you have pure PdCl2 or pure PdO it will read 100% Pd

Is there any way to analyze palladium metal?
I wonder how to analyze palladium metal without dissolving it in aqua regia.

 

[rusti2]

Is there any way to analyze palladium metal?
I wonder how to analyze palladium metal without dissolving it in aqua regia.

If you want to determine the purity of Pd, the gravimetric method of weighing it as palladium-dimethylglyoxime is very reliable. For use as a catalyst, the purity is normally so high that it requires determining the impurities of some metals with levels of a few units or tens of ppm.

 

[rusti2]

I study spent catalyst recover and create used Pd.

A yellow salt was formed, which is the final step in the Pd recovery process.

At what temperature should yellow salt be calcined to make Pd concentrate sponge?

When I calcination it at 310℃ for 5 hours, it became black palladium powder, but it was not in the form of a palladium sponge.

Should I calcination at a temperature over 800℃ instead of 310℃?


I have another question.

Is it better to use hydrogen peroxide instead of nitric acid to dissolve precious metals?

How much ammonia should be added when recovering Pd?

The precipitation of the yellow salt whose photo you sent is not quantitative, which means that the filtrate has traces of recoverable Pd.

 

[jsyouu]

If you want to determine the purity of Pd, the gravimetric method of weighing it as palladium-dimethylglyoxime is very reliable. For use as a catalyst, the purity is normally so high that it requires determining the impurities of some metals with levels of a few units or tens of ppm.

Can you share the original source of the attached material?

 

[rusti2]

Can you share the original source of the attached material?