Ashed chips concentrate, TAKE TWO

[VanMarco]

Hello!
I am back. I have incinerated and ashed more chips.
I did the concentrate with water too.
I already had a similar post as the previous time, I used HCl to dissolve base metals.
Now i have some extra nitric, and i would like to try that. But wouldn't adding nitric to the concentrate produce metastannic acid?
the concentrate is technically the heavier fraction, so gold, lead, tin, copper.
If i were to add nitric, base metals would go quick, leaving gold, maybe pt if present.
if i were to add hcl first, maybe tin, along with lead, copper (as it is in oxide form it would become cucl2) and no metastannic acid.
I am undecided.
Any recommendation?

 

[eaglekeeper]

Was your chips a mix of legged chips and BGA's?

BGA chips are a lot easier to deal with because of less base metals. I always separate those two types.

 

[VanMarco]

oh yes sorry i didnt mention it. it's chip from mobile phones, so smaller ones. some have legs, but still, all had tin.

 

[Martijn]

Hello!
I am back. I have incinerated and ashed more chips.
I did the concentrate with water too.
I already had a similar post as the previous time, I used HCl to dissolve base metals.
Now i have some extra nitric, and i would like to try that. But wouldn't adding nitric to the concentrate produce metastannic acid?
the concentrate is technically the heavier fraction, so gold, lead, tin, copper.
If i were to add nitric, base metals would go quick, leaving gold, maybe pt if present.
if i were to add hcl first, maybe tin, along with lead, copper (as it is in oxide form it would become cucl2) and no metastannic acid.
I am undecided.
Any recommendation?

With tin you mean solder, and no bronze?Then go for a HCl leach first to get the lead(why do you expect lead?) and tin.

And do not alloy the concentrate.

Copper can dissolve, if Copper oxide is present as you say, but this will be slowly, and only with the addition of air bubbled through.
This will save on nitric use, and you can leach the solids in AR, skipping the nitric step entirely.

If you want results fast, rinse out the HCl to pH neutral with distilled water before going for the nitric step to get the copper.

I don't expect Pt in Chips, but you never know. Leave that for the stockpot and the used AR filters pot.