Platinum Recovery From Ceramic Processors

[kurtak]

Thank You, the wet papers was very wet and heavy, I had to dry off it first. Because there was much water inside papers I thought it would be best to make it dry first on a electric hotplate with sand. After 3 hours papers finally dried off, then it was too late to replace it because some parts started to red glow and I left it until all turned to carbon. I haven't consider that sand will make some problems after in AR. So, now I have mix of sand, ashes and powder.

Tzoax

If the sand was a "very clean" silica sand doing an AR leach can still be done - the complication is that now you have to use a greater amount of HCl in making up your AR in order to cover the sand as well as the ash & metal powders --- because you are going after PGMs the leach solution needs to concentrated acid & not diluted (at least not to diluted if you are talking Pt) so you will be using more acid then other wise would have been needed --- this of course means creating more waste

Also filtering/washing all the solution out of the sand has become a greater problem - still do-able its just going to take a greater volume of water (& I hope you have a vacuum filter set up or you wont get it all washed out) this means a "huge" increase & dilution of you leach solution which in turn means a huge amount of evaporation to concentrate your solution back down before recovering your PMs

& that's if the sand is a "very clean" silica sand (which it does not look like)

On the other hand if its dirty sand - with clay in it &/or organic material &/or the sand its self is made up of mineral matter other then silica the "potential" problems have become much more complicated --- all of which would take far greater time to explain then I have time for

Kurt

 

[Tzoax]

Thank You, the wet papers was very wet and heavy, I had to dry off it first. Because there was much water inside papers I thought it would be best to make it dry first on a electric hotplate with sand. After 3 hours papers finally dried off, then it was too late to replace it because some parts started to red glow and I left it until all turned to carbon. I haven't consider that sand will make some problems after in AR. So, now I have mix of sand, ashes and powder.

Tzoax

If the sand was a "very clean" silica sand doing an AR leach can still be done - the complication is that now you have to use a greater amount of HCl in making up your AR in order to cover the sand as well as the ash & metal powders --- because you are going after PGMs the leach solution needs to concentrated acid & not diluted #at least not to diluted if you are talking Pt# so you will be using more acid then other wise would have been needed --- this of course means creating more waste

Also filtering/washing all the solution out of the sand has become a greater problem - still do-able its just going to take a greater volume of water #& I hope you have a vacuum filter set up or you wont get it all washed out# this means a "huge" increase & dilution of you leach solution which in turn means a huge amount of evaporation to concentrate your solution back down before recovering your PMs

& that's if the sand is a "very clean" silica sand #which it does not look like#

On the other hand if its dirty sand - with clay in it &/or organic material &/or the sand its self is made up of mineral matter other then silica the "potential" problems have become much more complicated --- all of which would take far greater time to explain then I have time for

Kurt

Thank You for explanation. The sand wasn't silica, I used plain river sand, Most likely organic dirty. I thought that incineration will take out all organic material and that sand will not cause problem in AR. After all, even if I loose some platinum this way #if there is any# the most of it should go into solution, and at least I could test it with stannous to see if it is present. There is not that much sand in it, I will not need much acid.
Now I will wash it with water and let it settle one day, then I will decant it and make AR solution, test with stannous and see if there is any platinum in there. I forget to say that all types of ceramic processors that I used here that contained any smd component like MLCC or resistors that contained Pt and Pd was previously removed with heatgun, so if there is a Pt it was most likely inside of the prosessors.

 

[ericrm]

why dont you simply take your incinerated material + the sand that close to it than incinerate this material again to white ash? this way you will make sure that everything is by the book. since your doing yield test you shoulnd left anything to the unknow... after all if the result isnt what you expected you will know that yo0u have done everything correctly

 

[Tzoax]

why dont you simply take your incinerated material + the sand that close to it than incinerate this material again to white ash? this way you will make sure that everything is by the book. since your doing yield test you shoulnd left anything to the unknow... after all if the result isnt what you expected you will know that yo0u have done everything correctly

Thank You, thats exactly what I will do.

 

[Tzoax]

I've made a brand new AR solution of ceramic processors and tested with stannous. The result was negative. So, there is no platinum in ceramic processors and if so, there is a very small quantity. Obviously the xrf scanner is not precise with the powders. Next time when i go check the xrf results, it will be from alloy.

 

[g_axelsson]

So the 5% Pt in this analyze wasn't there in the end. Do you still trust the result you posted about the MLCC powder left over after AR dissolving?

I sent out some mineral samples to a lab in Russia a number of years ago, but I stopped with that when I got results back that could not be correct. Either they mixed up my results with some one else results or their methodology was flawed. Either way, I could not trust anything that I couldn't verify myself so it was the end of using that lab.

XRF can be a very powerful tool, but if the operator doesn't understand how to use it or the instrument isn't programmed for that kind of materials then the results can be very wrong.

From the analyze it looks like the instrument is only programmed to read precious metal alloys and if it doesn't take into account the effect of contributions and absorption from non-metal elements there will be huge errors in the result.

Göran

 

[Tzoax]

So the 5% Pt in this analyze wasn't there in the end. Do you still trust the result you posted about the MLCC powder left over after AR dissolving?

I sent out some mineral samples to a lab in Russia a number of years ago, but I stopped with that when I got results back that could not be correct. Either they mixed up my results with some one else results or their methodology was flawed. Either way, I could not trust anything that I couldn't verify myself so it was the end of using that lab.

XRF can be a very powerful tool, but if the operator doesn't understand how to use it or the instrument isn't programmed for that kind of materials then the results can be very wrong.

From the analyze it looks like the instrument is only programmed to read precious metal alloys and if it doesn't take into account the effect of contributions and absorption from non-metal elements there will be huge errors in the result.

Göran

I was wrong, so my platinum fever is over.
And if I test alloy of anything the results of xrf should be relevant? Or even then it could be unaccurate?

 

[FrugalRefiner]

So the 5% Pt in this analyze wasn't there in the end. Do you still trust the result you posted about the MLCC powder left over after AR dissolving?

I sent out some mineral samples to a lab in Russia a number of years ago, but I stopped with that when I got results back that could not be correct. Either they mixed up my results with some one else results or their methodology was flawed. Either way, I could not trust anything that I couldn't verify myself so it was the end of using that lab.

XRF can be a very powerful tool, but if the operator doesn't understand how to use it or the instrument isn't programmed for that kind of materials then the results can be very wrong.

From the analyze it looks like the instrument is only programmed to read precious metal alloys and if it doesn't take into account the effect of contributions and absorption from non-metal elements there will be huge errors in the result.

Göran

I was wrong, so my platinum fever is over.
And if I test alloy of anything the results of xrf should be relevant? Or even then it could be unaccurate?

As Göran said, if the person using the XRF doesn't know what he's doing, or if the machine isn't calibrated for the types of metals in your sample, the results can still be inaccurate.

Dave

 

[MarcoP]

But what about palladium, isn't it used for bonding ceramics?

 

[patnor1011]

Probably not. What I have seen was AgPd alloy used for bonding in some IC packages. As far as I remember they were called Rabbit but I do not remember exact type. Like these - with pins on all 4 sides.
http://www.datasheetdir.com/package-TFBGA

 

[MarcoP]

Thanks Pat. After a quick search I found palladium it's used in frames in place of lead and in other applications palladium-ceramic it's used to hold heat, in the latter would off course not be good for processors lids.

 

[g_axelsson]

Just to clarify for those that reads this thread. When they are talking about lead frames, it's the metal strip with punched out leads that they mount the die on and connect the bond wires to. It's not the metal lead.
After the die is brazed to the lead frame and the bond wires bonded the whole package is molded in plastic and the legs cut off from the metal strip. Then the chip is ready for soldering.

Göran

 

[MarcoP]

Just to clarify for those that reads this thread. When they are talking about lead frames, it's the metal strip with punched out leads that they mount the die on and connect the bond wires to. It's not the metal lead.
After the die is brazed to the lead frame and the bond wires bonded the whole package is molded in plastic and the legs cut off from the metal strip. Then the chip is ready for soldering.

Göran

Thank you Göran for the great explanation, the following is the quote of the text where I've found that information. I still can't understand how a plating can replace a welding. I haven't searched more and will probably have more time in the next few days.

Lead frames are used to connect integrated circuits to other electronic devices. Some manufacturers use palladium to plate the frames as an environmentally preferable alternative to tin-lead solder.

Marco

 

[g_axelsson]

Just to clarify for those that reads this thread. When they are talking about lead frames, it's the metal strip with punched out leads that they mount the die on and connect the bond wires to. It's not the metal lead.
After the die is brazed to the lead frame and the bond wires bonded the whole package is molded in plastic and the legs cut off from the metal strip. Then the chip is ready for soldering.

Göran

Thank you Göran for the great explanation, the following is the quote of the text where I've found that information. I still can't understand how a plating can replace a welding. I haven't searched more and will probably have more time in the next few days.

Lead frames are used to connect integrated circuits to other electronic devices. Some manufacturers use palladium to plate the frames as an environmentally preferable alternative to tin-lead solder.

Marco

There is no welding in that quote. (welding = melting the base metal, brazing = high temperature soldering, soldering = connecting two object by another melted metal but the base isn't melted.)
The tin-lead solder mentioned is the plating on the legs of the chip. By substituting it against palladium plating the base metal is still protected from oxidation and can still be soldered without problems.

Göran

 

[MarcoP]

Now that make sense, thank you! I just realized that in english welding and soldering refer to two different techniques while in my mother language there is only one word for it. Now I can start paying attention to those differences. Thanks to you I've just improved my english

Marco

 

[g_axelsson]

My pleasure! 8)

Göran