Video discussion. Gold recovery from 14kg of CPU by using the lead bath method.

[Martijn]

SS cage works as long as its not fine mesh. Too fine of a mesh and the "pores" gets clogged by the solidified litharge.

This is the latest lead bath I did:

Great feed back and great video showing some mistakes and learning points! Those are the best imo letting people learn from your mistakes.

 

[Martijn]

@Owltech ;
How do you experience the lead fumes, if any? Are there a lot fumes or is it a negligible? Do you wear a mask?
Do you reduce the lead oxide back into metal after cupelling?

 

[Martijn]

I just saw you wear a mask in the video. So something to keep in mind when I start experimenting.
I was wondering if the button with silver and gold can be put in the silver cell after cupelling.

 

[Owltech]

@Owltech ;
How do you experience the lead fumes, if any? Are there a lot fumes or is it a negligible? Do you wear a mask?
Do you reduce the lead oxide back into metal after cupelling?

Lead fumes are a nasty thing, use common sence and a mask rated for welding fumes, change your clothes before and after work, wash yourself after work with plenty of soap, position yourself so the wind is at your back, don't exceed the needed temperature. A mobile weldig fume extractor should be more than enough to deal with the fumes from small batches like mine. I never experienced any health problems, but it's never too late. I drink 2 liters of milk every day, but thats because I'm loving it, some old folks say it helps for heavy metal poisoning.

Yes, reduction of litharge to lead easily done with a source of carbon

 

[offtrailhiker]

In a back yard, a respirator on a windy night!

 

[4metals]

(I read somewhere that they started adding silver to solders to inhibit the solubility of gold, which is the opposite of what I'm trying to achieve).

Many years ago I worked in a connector factory and learned one of the major reasons for failure of solder joints was the formation of gold stannate in the solder joint which was brittle and often suffered from stress fractures. The solder was tin lead. The solution was to switch to a silver based solder that did not form the brittle alloy as there was no tin in the solder. I think that is what the reference to gold solubility was about, not solubility as much as not forming brittle joints prone to stress cracking.

I like throwing the Silver in while stripping the gold as it is actually a refining step if the Silver you add is sterling Silver. Either way it is a good way to process these chips. On a large scale the lead would cause environmental and health issues though.

 

[Yggdrasil]

If one ramped up the exhaust system.
Could this be suitable for running chips directly?
Maybe just pyrolyzing?
The Carbon is useful for the Lead Oxides after all.

 

[4metals]

In the US the dangers of lead exposure seem to make its use guarded. However they never give assayers a hard time. And for years millions of cars, hundreds of millions of cars, burned leaded gasoline spraying the tetraethyl lead all over the roads.
Lead fume condenses out of the air quickly and is easily caught in a bag house or a welders fume hood.

 

[Yggdrasil]

In the US the dangers of lead exposure seem to make its use guarded. However they never give assayers a hard time. And for years millions of cars, hundreds of millions of cars, burned leaded gasoline spraying the tetraethyl lead all over the roads.
Lead fume condenses out of the air quickly and is easily caught in a bag house or a welders fume hood.

I was thinking on the VOCs from burning chips directly.
The Lead must be handled correctly of course, but that should not complicate things much.

 

[4metals]

VOC’s are easily handled with an afterburner with a 2 second dwell time. Lead may be harder to be permitted for. Lead recyclers get tons of grief.

 

[Owltech]

If one ramped up the exhaust system.
Could this be suitable for running chips directly?
Maybe just pyrolyzing?
The Carbon is useful for the Lead Oxides after all.

I haven't tried it directly, but after burning and crushing it works great.

 

[Owltech]

I like throwing the Silver in while stripping the gold as it is actually a refining step if the Silver you add is sterling Silver.

I use silver contacts as a source of silver (silver content about 85%), which is refined during cupellation.

 

[Ayham Hafez]

I wonder if copper bath can do the same work as lead bath in collecting PM's.

Since I use copper refining cell, and always I have E-waste that been smelted to make copper anodes, may I soak the high grade materials such as ceramic CPU's or high grade ic chips into the molten copper before cast the anode? Will it do the same work of lead or lead have better collecting ability for PM's?

 

[Yggdrasil]

I wonder if copper bath can do the same work as lead bath in collecting PM's.

Since I use copper refining cell, and always I have E-waste that been smelted to make copper anodes, may I soak the high grade materials such as ceramic CPU's or high grade ic chips into the molten copper before cast the anode? Will it do the same work of lead or lead have better collecting ability for PM's?

With Lead it can be done a significantly lower temperatures.

 

[Ayham Hafez]

With Lead it can be done a significantly lower temperatures.

I understand, but temperature is not an issue since I already melting the anode.

 

[Yggdrasil]

I understand, but temperature is not an issue since I already melting the anode.

Just do an ordinary smelting with the proper flux.

 

[Ayham Hafez]

Just do an ordinary smelting with the proper flux.

Ceramic CPU'S are very rare now a day's unlike other materials, for example now I have about 1 KG of ceramic CPU'S, my crusher, rod mill, crucible, mold, and other stuff are too big to process only 1 Kg of CPU'S, and I'm afraid to loose some of their value if I mixed them with other E-waste material, so I think the proper way to get their high value is to process them using scorification or lead bath, in this way you can see the value of them very easy going throw the molted lead, but I wonder if I can use copper instead of lead without loosing any of their yield.

 

[Yggdrasil]

Ceramic CPU'S are very rare now a day's unlike other materials, for example now I have about 1 KG of ceramic CPU'S, my crusher, rod mill, crucible, mold, and other stuff are too big to process only 1 Kg of CPU'S, and I'm afraid to loose some of their value if I mixed them with other E-waste material, so I think the proper way to get their high value is to process them using scorification or lead bath, in this way you can see the value of them very easy going throw the molted lead, but I wonder if I can use copper instead of lead without loosing any of their yield.

I'd guess, but the increased temperature may mean more issues in the stirring and separation stages.
I think they do not need fine crushing just coarse and then add them along the rest of what you smelt.
The values will be there, so where you extract them should not mean much right.
The after processing will be identical will it not?

Unless you get in batches that need separate processing due to accountability.
Then I'd go for Lead anyway.