White Precipitate from China and Glass

[campboss]

Hello, My name is Bob. I live in SLC, Utah. I am retired and started scrapping electronics about 5 years ago, about the same time I started reading the Forum. About 2 years ago I started recovering PM's from the electronic scrap. Not wanting to raise Harolds ire, I have been hesitant to post. Right as he is about stupid questions from those who won't take the time to study. While reading Hoke and the forum and gaining what little knowledge I have from the likes of Harold, Laser-Steve, Butcher, Noxx and several other learned pros on the Forum, I have had success with fingers, stripped plated whole boards, chips, cpu's and pins. I've made mistakes and researched the answers to correct them in most cases. I wish to thank the members of the Forum for their time and effort, while sharing their knowledge in recovery and refining and trying to keep us all safe, while so doing. I do have a question. I acquired some unmarked china with what looks like gold trim. I broke off a few pieces and put it in HCL. No reaction. I added CL, 4/1 ratio and it reacted instantly. A white precipitate dropped like a rock to the bottom. When I tested the solution with Stannus Cloride it was barren. I have searched the forum for an answer as to what the precipitate may be and found only a few posts alluding to a white mud, when dealing with china and glass, but no definitive answers. I appreciate the service the members of this Forum provide and thank you for any response to my question.
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[solar_plasma]

Respect!

That said, did the solution get a yellow color and how large an areal was golden per liter of solution? I wished, I could help you with the white mud, but I have never had this. If stannous is negative and if the solution didn't get a yellow tint at least, it might have been golden paint without any gold or it has been a really, really small ammount of gold in far too much solution.

 

[Pantherlikher]

Hello campboss

I've done a ton or 2 of gold trimmed glassware.
You put way to much bleach in and raised the Ph and dropped salt...White stuff.

Ton being key to showing anything when tested. 10 whole pieces and you might get a positive test. Remember, there is very little surface area to begin with and it's usually thin.

I use a large enough basin to cove the trim on say a plate with HCL. Then a splash of bleach, maybe 1oz. Just enough to get a fizzing. Then turn the plate as the gold disappears. When done, I move to another basin and squirt water over plate to rinse.

3-4 days of doing this maybe 5 hours a day and I'm guessing a couple few grams out of it. I need to refine the 10 or so I have to be sure.

I wash each piece and rinse and when the reaction slows down, I'll add another splash of bleach and continue. When it reaches a more neutral PH...too much bleach, I start to see the white precipitate(salt). Adding more HCL will redissolve it but the reaction gets really slow. Chlorine gets used up and PH is too high to work fast again so, I'll pour solution off, test, and let sit on a warmer to expel any Chlorine still free. Then add SMB and let sit for a few days until precipitation.

I'd say it is worth the effort if you can get tons for free. Lots of labor because each piece does not have much so bulk is key.

B.S.

 

[Harold_V]

Hey, Bob!
Welcome to the board, and thanks for observing our simple rules of learning the basics before asking questions.
How's things in Utah? Haven't been back there since the year 2000. I lived in the Midvale area before I moved to Washington.

Harold

 

[campboss]

Thank you for the response. I only did a test with 40ml of hcl and 10ml of cl. Too much cl is the reason without a doubt. The amount of material was a few broken chips with a 1/2 in gold looking trim. The solution was yellow. I think I will not waste time on unmarked pieces again. There is little enough gold on the marked pieces. Thanks
again for the help.

Harold, We are having what I think is the warmest winter in the 40 years that I have lived in Utah. I think I used your services in 1983 to have you take the gold out of 2-55 gallon drums of black sands and concentrate from a gold mine I had at that time. Anyway, you did a good job, the gold mine was a bust. Thanks for your help. Bob

 

[Harold_V]

Harold, We are having what I think is the warmest winter in the 40 years that I have lived in Utah. I think I used your services in 1983 to have you take the gold out of 2-55 gallon drums of black sands and concentrate from a gold mine I had at that time. Anyway, you did a good job, the gold mine was a bust. Thanks for your help. Bob

Did you live in Taylorsville at that time? If so, I remember you, but had forgotten your name.

Harold

 

[campboss]

I still live in Taylorsville. Last name Pankow. I wish you were still here. Our only option is Cascade and since they are the only game in town, they make the rules. Competition is always better for the consumer. I learned a lot more about placer mining after that first episode. If gold values were $1,200 an ounce back then I would still be there. As it was $300 gold just couldn't cut it. I realize labor, fuel and equipment costs have risen, but not 4 to 5 times like gold has.