catalyst processing and analysis

[david1205]

Hi, All,
I got batches of sample which came from converter catalyst of cars. Normally it will contain Rh, Pt and Pd inside the ceramic converter. We used the Nickel Sulfide method to fusion the samples in lieu of the traditional lead oxide method which has the poor recovery on Rh. Since we did some lots, the reproducibility is not very good and not in consistence. This is our first trial.
Therefore, I would like to ask is there any reference which I could refer to regarding on processing, sampling for car converter catalyst? or any suggestion and tips on analysis we could improve in Nickel sulfide fusion method? or any better analysis method for converter catalysts? Thanks a lot.

 

[fireguy]

Hi, All,
I got batches of sample which came from converter catalyst of cars. Normally it will contain Rh, Pt and Pd inside the ceramic converter. We used the Nickel Sulfide method to fusion the samples in lieu of the traditional lead oxide method which has the poor recovery on Rh. Since we did some lots, the reproducibility is not very good and not in consistence. This is our first trial.
Therefore, I would like to ask is there any reference which I could refer to regarding on processing, sampling for car converter catalyst? or any suggestion and tips on analysis we could improve in Nickel sulfide fusion method? or any better analysis method for converter catalysts? Thanks a lot.

Hi David:
Normally, the catalyst substrate is a ceramic material, which is going to be difficult to complex in the fire assay fusion. This will probably require your sample size to be small, which is in turn going to require a very well blended and finely ground sample.

How are you preparing your sample? I would suggest using a ring and puck type pulverizer as they will blend while they grind, and you can grind finer by increasing the grinding time. You can see details on this type of equipment here:
http://www.lmine.com/product/25100.html

Alternately, you could use a small batch ball or pebble mill.

If you are already doing all of this it may be necessary to do some adjustments to your flux.

 

[devan]

Rh is a tough element for the fire assayist. We have had good luck using a Gold inquart to capture the Rh in samples containing 1% or less of Rh. For anything higher, we use a SnO fusion process. This SnO method is also very effective for the determination of Ru and Ir.

 

[david1205]

Hi, Devan,
I used gold inquart/pb to capture the Pd, Pt and Rh. So far on Rhodium part, our result is OK. But on Pd and Pt part, there are still having around 2 to 3 ounce less than actual XRF result. I don't know whether you have such kind of experience on this. How to solve this issue or recovery the lost?
Regarding the SnO fusion method, could I ask for a copy of this method? Thanks a lot.

 

[fireguy]

Hi, Devan,
I used gold inquart/pb to capture the Pd, Pt and Rh. So far on Rhodium part, our result is OK. But on Pd and Pt part, there are still having around 2 to 3 ounce less than actual XRF result. I don't know whether you have such kind of experience on this. How to solve this issue or recovery the lost?
Regarding the SnO fusion method, could I ask for a copy of this method? Thanks a lot.

David:
Tin collection discussion and methods here:
http://books.google.com/books?id=FV...latinum-group metals, gold and silver&f=false

Nickel Sulphide collection seems to be more common so you may want to investigate that:
http://www.ledoux.com/IPMI Las Vagas.htm