Palladium Problem

[radhia87]

Currently we conducting palladium digestion but we encounter several of problems. Kindly refer attachment for data.

It seem total quantity of palladium in raw material does not match with total quantity palladium in solution. Besides that, ICP detected zero in substrate. Our questions are

1. Why both data does not match? Is it because raw material not fully digest.
2. But if not fully digest, suppose still got content in substrate. But ICP detect zero for substrate
3. Is it possible substrate still have palladium and because palladium already convert into other form(maybe complex or etc) & icp unable to detect?
4. Is it possible palladium already evaporate?
5. We know that silver in silver chloride cannot be detected by icp. Is it same happen as palladium chloride?


Your attention and cooperation is highly appreciated.

I am looking forward to hear from you soon.

 

[Lino1406]

Is always exactly 1:2 factor? give detail of solution test

 

[radhia87]

Detail of solution test is 1L of 68% HNO3 + 1 L of H2O . Weight of material poured into this solution is 1kg.

 

[Lino1406]

And?.. exact procedure

 

[radhia87]

Procedure

1. Test Palladium content in chip resistor using icpoes
2. Result for palladium is 0.045%. So, estimate palladium to get from 1kg Chip resistor is 0.45g
3. Prepare solution: 1L H2O + 1L 68% HNO3
4. Pour slowly 1kg chip resistor into solution number (3)
5. Wait until no brown gas released (meaning until reaction complete)
6. Test solution for Pd content using icpoes
7. Result is 113mg/L. thats mean total pd in 2 L solution is 0.226g
8. Only 0.226g palladium in the solution. Suppose 0.45g if base on raw material result. Why too much difference?

 

[Lino1406]

This citation says that the problem is with the solids analysis
"Solid sample digestion because solid samples cannot be introduced into the plasma directly, they must be either transferred into the plasma via a carrier gas (e.g. electrothermal vaporization, laser ablation), or they must be made into a solution. The main techniques used to dissolve solids are acid digestion and fusion."

 

[g_axelsson]

1. Test Palladium content in chip resistor using icpoes

How is this step done? Just as Lino pointed out you can't put a resistor directly into an icpoes (Inductive Coupled Plasma Optical Emission Spectroscopy).

Poor sampling methodology? If you pulled a non-representative sample you could come up with any results at all....

Göran

 

[radhia87]

For No 1 of course is not direct analysis in solid form. The sample go through several steps of of sample preparation before analyze by icpoes. The result is quite accurate because i already confirm with external accredited lab. Meaning result i get compare to result that generate by external accredited lab is almost same which is 0.045%.

Any other possible cause? Could palladium evaporate?

 

[Lino1406]

"Pour slowly 1kg chip resistor into solution number (3)" did you grind those chip resistors before processing?

 

[radhia87]

Yes i did poured slowly and I did grind chip resistor until become powder form before poured into solution number 3

 

[Lino1406]

Ran out of ideas

 

[Yggdrasil]

Just a question here.
Are you treating resistors or MLCCs?
Resistors should not contain Pd should they?
Maybe some Ru but not much else as far as I have seen here.
Correct me if I'm wrong.

 

[Platdigger]

Could it be part of your pd was in the form of pdo?

 

[radhia87]

Yggdrasil : Yes it's chip resistor and it's contain palladium which is 0.045%.

Platdigger: If Pd in PdO, it that the reason icpoes unable to detect.

 

[Platdigger]

The nitric will have a hard time dissolving palladium oxide.