Pulverized ic chips > Straight AR >>???

[razvanflorin]

Hello ! I'm asking for some advices.

Personally, the most used gold recovery method by me is the ''Straight Aqua regia,, process.
I use 3 parts of hydrochloric, 1 part of nitric and 1 part of water.
The process works more than fine on gold plated pins and common materials.

But now i want to try something different and i think that it would be something wise to ask your advice.

My idea is to pulverize ic chips & bga chips and put them directly in aqua regia after the dissolution i would filter the solution, get rid of the excess nitric and precipitate the gold.

would the organic material(plastic from ic's) affect the dissolving/percipitation process ?

 

[kernels]

Ha, every year or so I try this method again and am always disappointed. Initially I didn't have a vacuum filter, so that part of the process was a disaster, made a huge mess, very difficult to work with. The time I saved by not separating the plastic / carbon from the metal was more than eaten up by the chemistry part taking longer.

The other big problem is that my yield was always lower than expected when doing it this way, usually down around 20 to 30% of expectation. My hypothesis is that Gold is absorbed into the Carbon (I pyrolize before ball mill)

These days I just spend a few hours over the blue-bowl and separate the metals from everything else before starting with the chemistry.

 

[razvanflorin]

Ha, every year or so I try this method again and am always disappointed. Initially I didn't have a vacuum filter, so that part of the process was a disaster, made a huge mess, very difficult to work with. The time I saved by not separating the plastic / carbon from the metal was more than eaten up by the chemistry part taking longer.

The other big problem is that my yield was always lower than expected when doing it this way, usually down around 20 to 30% of expectation. My hypothesis is that Gold is absorbed into the Carbon (I pyrolize before ball mill)

These days I just spend a few hours over the blue-bowl and separate the metals from everything else before starting with the chemistry.

Well.. Thanks you very much for your advice !

That means we have to separate the organic material... um.. not a problem but i really don't like the
water separation table

would a electrostatic separator like this works better than a water separation table ?

 

[canedane]

I will seperate bga and ic chips.
Cut of the green bottom of the bga, AP process the top, pyrolize, incinarate, pan the ash, and then use calculated AR. Not a drop more nitric than needed.
Im not telling this way are the best,it is how i will do it, and if im wrong, please let me know.
Ic chips have Sn, how would you deal with that? You have to get rid of the Sn before you use AR.
Henrik

 

[razvanflorin]

I will seperate bga and ic chips.
Cut of the green bottom of the bga, AP process the top, pyrolize, incinarate, pan the ash, and then use calculated AR. Not a drop more nitric than needed.
Im not telling this way are the best,it is how i will do it, and if im wrong, please let me know.
Ic chips have Sn, how would you deal with that? You have to get rid of the Sn before you use AR.
Henrik

Yeah.. well your method is a little bit complicated.. i'm trying to do it simple, as i want to do this in big quantities.

and dude, you're wrong with the SN.. if you go Straight AquaRegia, the SN(TIN) will not be a problem, it will directly dissolve.

 

[kernels]

I will seperate bga and ic chips.
Cut of the green bottom of the bga, AP process the top, pyrolize, incinarate, pan the ash, and then use calculated AR. Not a drop more nitric than needed.
Im not telling this way are the best,it is how i will do it, and if im wrong, please let me know.
Ic chips have Sn, how would you deal with that? You have to get rid of the Sn before you use AR.
Henrik

No need to AP process the BGA top before pyrolization, it is basically just a plastic blob. I never incinerate after pyrolize since it's easy enough to remove the carbon after the ball-mill stage. It is impossible to pan bond wires from IC material, they are long and spindly, do not settle in a pan like alluvial Gold. I like to wash the worst of the carbon out with a bucket, then blue-bowl what's left to retain mostly Copper and Gold.

When I process small BGA chips where there is a lot of Tin, I will run the washed material in hot HCl until the Tin is dissolved before washing out the acid and then progressing to either HNO3 or AR.

 

[kernels]

As with most processes, the way we process a few kgs of material as a hobby does not scale very well into industrial quantities. If you really have huge amounts of material to process, you probably want to at least investigate how it is done industrially. I expect smelting into anodes and Copper refining would be very common.