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View Full Version : How do You Transfer a Small Amount of Precipitant to a Melting Dish ?



gunDriller
4th December 2011, 05:55 PM
I have a cupful of brown in the bottom of the measuring cup I used to do a precipitation.

The brown is gold, from gold plating on PCB's.


But now that I want to melt it into a bead - I need to transfer it to a melting dish or a crucible. I have watched the LazerSteve videos 3 to 5 times each. I'm done with the siphoning, now I want to melt.

But to do that, I have to transfer the precipitant to a melting dish or crucible.


It is sitting on top of the fireplace at about 100 degrees F, drying out after siphoning. Then there was some salt I chased around using a spray bottle with distilled water, then I used a square of TP to remove that.

http://oi42.tinypic.com/mkgklu.jpg

There's not a whole bunch of it (the brown deposit). Normally, I would just invert the measuring cup, tap out the substance onto a piece of paper, crease the paper, and slide it into the crucible with the help of gravity.


But I have a feeling that if I do that with this, I will lose a bunch of the precipitant, a treasured brown powder.

I was thinking of reinforcing the glass cup on the sides with Gorilla tape, a special kind of duct tape. Then if the cup breaks when it's heated, it's position will hopefully not change much.

Anyway, I was thinking of putting the glass cup on a hot plate for a pre-heat, and then using a torch to hopefully apply some 2000 F to the precipitant to get it to melt. I know this might break it, but if I get some decent small gold beads out of it, I could live with that.


It seems logical to do the precipitation in a container than is suitable for both the precipitation & siphoning AND the melting of the precipitant.

beefsteak
4th December 2011, 06:33 PM
You transfer it with a sable paintbrush dedicated to such tasks. Then you rinse out your container if you fear you've missed any, into your filter, and keep accumulating in your filter for however long you think you can maintain the integrity of your filter media fibers. Harold calls such filters, his savings account...

Fervently hope you don't use any glass vessel in the manner you are describing.

E. Haney
5th December 2011, 11:56 AM
You absolutely cannot melt that gold in the cup, even Pyrex, while it won't shatter, it will probably break if heated too quickly or unevenly, because Pyrex melts at ~400F below gold's MP, the gold will adhere to the glass.

Wipe the cup out with a small section of paper towel, place in the melting dish, wet with denatured alcohol, light, add flux, melt.
And buy a magnifying glass, because that gold bead is going to be tiny, itty bitty. It won't even cover the cost to replace the measuring cup.

gunDriller
5th December 2011, 05:13 PM
http://oi44.tinypic.com/w15h6w.jpg

i ended up using a round stick with a pointy end to coax the powder into a pile, in the measuring cup.

then dumped it onto a sheet of aluminum foil, which i partially folded, to slide the powder into the melting cup.

it ended up measuring 0.3 grams. There was a small amount of salt going in, perhaps that is the dark crap that sort of glued the bead to the ceramic melting cup.

Dogman
5th December 2011, 05:16 PM
Well done!

beefsteak
5th December 2011, 10:08 PM
Gunny, That your first one? Nice job, even with the non-gold residue visible.

Oh, and did your Boron Silicate Glass measuring cup cost you $16.50-ish? That's what a 2-9s fine YG bead weighing 0.3 grams is worth.;D

You might consider shopping other than where Haney buys his housewares...You do know HE shops at Abercrombie and Fitch Flagship Store in NewYork, don't you?

horseshoe3
6th December 2011, 02:53 PM
So now that you know how to do it, are you going to be able to scale up and make it profitable? Or at least cover your time?

gunDriller
6th December 2011, 03:15 PM
Gunny, That your first one? Nice job, even with the non-gold residue visible.

Oh, and did your Boron Silicate Glass measuring cup cost you $16.50-ish? That's what a 2-9s fine YG bead weighing 0.3 grams is worth.;D

Yes, that's my very first one. I put it in a small plastic Ziploc & carry it in my pocket.

I made about 1 cent per hour. totally worth it !

I got the impression from Steve that the reaction is reminiscent of those "snow cube" paper-weight things, except black snow instead of white snow.

But in my case it was more like "minor snow flurries" (Steve's result being a blizzard). The gold precipitate first showed up as minor wisps of dark colored smoke, barely visible.

It's good to learn that even that can result in worthwhile results.

I guess Mother Nature sometimes works her gold processes over millions of years, so who am I to hurry the process ? ;)



So now that you know how to do it, are you going to be able to scale up and make it profitable? Or at least cover your time?

Not exactly my goal, but, perhaps if I am patient. I am happy just to learn the process.


EDIT ~ OK ... all right ... I do confess to having one gold-collecting related fantasy: I'd like to have a one cubic inch piece of gold. Because of gold's density it would be about 10 Troy Ounces. That would be cool ;)