Processing transistors

[kjavanb123]

Following my post in type of scrap about processing transistors, here is what I have done so far, it is a very time consuming and attention seeking process,

1- Place transistors as is in a beaker, cover it with 50% nitric acid
2- Place the beaker insdie a tall plastic bucket as it always foams even at room tempreature.
3- Covered the mouth of beaker with a damped mask, it helped a lot during the process to keep the Nox fumes down.
4- Put the beaker on a hot plate, and add the transistors two or three at most,
5- The circular types of transistors are the most violent reaction once dissolving in nitric.

To be continued.

Here are some photos of the process,


And this is after 2 hours of boiling, finally only gold foil remains,


I went to do the whole batch and things got foamed up, but thanks for the bucket it captured all the gold foils,


Main beaker with some filtering, transistors were added to avoid more foaming,


I rinsed the solution to another bucket to collect the foils and this thick iron nitrate I am guessing (rusty color mud),
To be incinerated at the end of process for AR leach,


Regards,
Kevin

 

[yar]

In your fourth picture is that a space heater the beaker is sitting on? Is that what you are using as a hot plate?

 

[kjavanb123]

No that is what I use to dry my gold powder.

As GoldSilverPro suggested better to use stainless steel buckets of 316, and boil them in it.

Regards
Kevin

 

[resabed01]

You have boil overs because you add all of the transistors to your 50/50 nitric at the beginning.
If I can offer some advice, learn to do small, controlled additions of nitric to your batch. This will take more time but will prevent boilovers.
Start by adding some distilled H2O to the transistors. Then add heat to bring the batch to about 80 deg C.
Once hot, add small amounts of 50/50 nitric to the batch and wait for the reaction to complete before adding more.
This will prevent excess nitric in solution when you are done. Once you get a bit of experience doing it this way, you will learn how much nitric to add and when to get the job done quickly and have no boilovers.

 

[yar]

You have boil overs because you add all of the transistors to your 50/50 nitric at the beginning.
If I can offer some advice, learn to do small, controlled additions of nitric to your batch. This will take more time but will prevent boilovers.
Start by adding some distilled H2O to the transistors. Then add heat to bring the batch to about 80 deg C.
Once hot, add small amounts of 50/50 nitric to the batch and wait for the reaction to complete before adding more.
This will prevent excess nitric in solution when you are done. Once you get a bit of experience doing it this way, you will learn how much nitric to add and when to get the job done quickly and have no boilovers.

When you say " add some distilled H2O" does that mean just just add enough to cover the material? I only ask because I have 3 pounds of TO5 resistors that I will eventually process and I am studying to find out the best way to process them.

 

[yar]

No that is what I use to dry my gold powder.

As GoldSilverPro suggested better to use stainless steel buckets of 316, and boil them in it.

Regards
Kevin

It looks like the reaction is taking place on the heater. I was wondering if the fumes were attacking that metal grating or the heating elements themselves. Not trying to stir up a hornets nest but that is what it looks like is happening in the fourth picture.

 

[resabed01]

When you say " add some distilled H2O" does that mean just just add enough to cover the material? I only ask because I have 3 pounds of TO5 resistors that I will eventually process and I am studying to find out the best way to process them.

Yes, you could cover them with water. Water will be needed to complete the reaction. I imagine it will take quite a bit 50/50 nitric to break down 3 pounds of transistors and that 50/50 nitric will have it's own water already.
You don't want your solutions to become so voluminous it doesn't fit in the vessel. More water added means more waste to deal with.

I'm not endorsing using nitric for removing the base metals from T05 transistors as the best way, but it is one way to do it.

If it were me, personally, I would use AP although the process would be very slow.

 

[kurtak]

When you say " add some distilled H2O" does that mean just just add enough to cover the material? I only ask because I have 3 pounds of TO5 resistors that I will eventually process and I am studying to find out the best way to process them.

Yes, you could cover them with water. Water will be needed to complete the reaction. I imagine it will take quite a bit 50/50 nitric to break down 3 pounds of transistors and that 50/50 nitric will have it's own water already.
You don't want your solutions to become so voluminous it doesn't fit in the vessel. More water added means more waste to deal with.

I'm not endorsing using nitric for removing the base metals from T05 transistors as the best way, but it is one way to do it.

If it were me, personally, I would use AP although the process would be very slow.

This is one of those were there's more then one way to skin a cat things --- personally I think I would go with a straight HOT HCl (low simmer type boiling) treatment to get rid of the iron - which would be faster then AP - but not have the problem of a foaming reaction boil over with nitric (though it would be a bit slower then nitric)

So - HOT HCl (low simmer type boiling) would be a trade off between AP & nitric time wise

Kurt

 

[yar]

Thank you Kurt and resabed for the responses. I think I will remove the "top hats" first and process them using the crockpot method. If I did use nitric I know I wiild have have to do them in small lots and not the whole 3 pounds at once.