Non-Chemical Looking for consult (Paid) over skype.

[pinwheel]

Looking for consult (Paid) over skype. Can send $ through paypal.

I am looking for a one hour consultation regarding obtaining Au from milspec pins via a typical plated jewelry type recovery process. Especially pertaining to zinc and the troubles this can cause. PM me if you have a lot of experience with pins and professional level recovery processes. I will try to make it short and painless.

 

[Palladium]

You could just ask here and save the money.
If you're doing large volumes their is only two ways i can think of to do it efficiently. One would be cyanide and the other would be a sulfuric stripping cell. The first with cyanide i'm not sure of because you mention zinc. I've never used cyanide, but i do have a question for those that have. I know it doesn't attack the copper, but if you have an alloy high in zinc as the base metal would it cause the gold to precipitate on the surface like it does in ar or is that a function that can be regulated with the cyanide?

 

[ericrm]

there is a lot of ways to do it lol, the thing is that pins a kind of the easy part... it is like paying somone to teach you how to put windshield washer in your car because you want to start taking care of it yourself.....

anyway maybe you have question other than pins and use that occasion to ask it...

edit:trying to make my post usefull...
you can
use sulfuric acid cell
salt cell
javel cell (dont know if that one realy worked but i had read it somewhere)
ap
ar
pyrania solution
sulfuric and nitric
nitric acid alone
cyanide leach
iodine leach
even pass them in a ball mill to abrade the gold at some extend (it seem to have worked for some silver plated item)
theyr is probably way that i dont think of righ now...like vinegar or ....

my question for you would be how much pins are your treating how much often and where....

 

[pinwheel]

We have continuous material flow and can currently run about 1 pound per hour of clean pins.

we were doing small test lots at a jewelry refinery and the results from 5 gram samples of various milspec pins were coming back at 1.6% of the gross pre-melt weight which is exactly what we want to see. But then I upped the test to 150 grams of mixed pins and the refinery said that the zinc content was sputtering all over the place and fell out of the crucible and was burning a hole in the cement floor. Basically he said it ruined any chance of recovery.

So why would a larger lot of the same pins cause such an event?

My basic question is this:

Is there a way to adjust his technique so that we can deal with the zinc base metals that pop up on occasion? I do not know why, but he says zinc is a problem metal for them.

Has anyone done pins with a furnace and got good continuous results?

 

[ericrm]

you will need some knowledgable member to answer that one but for myself i have melted brass and it didnt splutered on the floor.... i did got some very bright reaction while melting white metal but still didnt splutered all around...
edit: i use a propane furnace maybe theyr furnace is different...

 

[pinwheel]

He stated that he thinks its when zinc goes over 10%, but was not really sure. He showed me a photo and it looked like a white firework exploding on the floor. The results by xrf were 81.3 Cu, 13.7 Zn, 1.4 Ni, 1.1 Pb

He can't get a gold reading, yet I know for certain its there in the sample somewhere.

 

[Lou]

Run mil-spec (all grades) frequently. We just melt them, sample, add more copper and plate.
I find it to give better yields over any strip operation.

Zinc burns blue FYI.
Unless you have a particular love for refining them, I'd be a buyer.

 

[pinwheel]

This is the button. Looks like gold to me.

 

[Lou]

Looks like brass that may have gold in it to me

 

[pinwheel]

makes sense I guess. I am quickly figuring out that xrf is not the best solution here.