Doing AuCl+SMB Precipitation in a Crucible

[Photobacterium]

I have just siphoned off the clear liquid and now there is a beautiful brown deposit on the bottom of the glass container I used for the precipitation.

Now that I am faced with the task of melting that brown deposit, which is hopefully gold ... this is on the tail end of the AP/ Acid-Clorox method, from LaserSteve's video ... I realize how convenient it would be to just have that brown deposit on a crucible, then to put it in my kiln and melt it.

As it is, I'm not sure how to transfer the brown powder to a crucible or melting dish... besides VERY CAREFULLY :shock:

This batch started with 200 grams of gold-plated fingers from PCB's. Estimated 1/2 gram to 1 gram of Gold bead, which may not be pure.


I was thinking about putting some Gorilla Duct Tape (really good duct tape) around the glass cup with the (hopefully) gold (I used a Pyrex type measuring cup, 1 quart, to do the SMB Precipitation) ... reinforcing it with the Gorilla Tape (in case it breaks) ... then putting it on a hot plate for a pre-heat ==> then using my oxygen-propane mini-torch to melt the brown stuff into beads.


When you're dealing with a small amount of finished gold powder, how do you normally transfer it to a melting cup ?

 

[Geo]

never try to melt in glass of any kind. after washing and rinsing your powder in the Pyrex container just evaporate the water until the powder is dry and moves freely.do you have a melting dish? if not, put everything away until you get one. lazersteve is a good place to get one, just order one or two or in a case like mine 5 at a time. :shock: :lol: prepare your dish as instructed from the forum and melt your button with the assurance that you are doing the right thing.

 

[qst42know]

Because you used a Pyrex measuring cup to do this is don't heat it from below on a hot plate in will break.

GSP mentioned using a light bulb to dry filters in a filter funnel once a long time ago. I think you might have some luck rigging the same in your measuring cup. Just don't let it touch the sides or anything else while on. The radiant heat might be slow but less likely to break your cup.

 

[Photobacterium]

I have been drying it above the fireplace.

After drying it the first time, there was a small amount of salt. I chased that around with a spray bottle to a location away from the gold, then dabbed at it with a wad of toilet paper & threw that paper in with the filters (the possible "future recycling" pile.)

It seems like the brown powder wants to stick to the glass of the measuring cup.

 

[samuel-a]

glass + torch = bad idea.
Unless you are using a fused silica type of glass, i can't see how in the world you'd pull this off.

After drying it the first time, there was a small amount of salt. I chased that around with a spray bottle to a location away from the gold, then dabbed at it with a wad of toilet paper & threw that paper in with the filters (the possible "future recycling" pile.)

It seems like the brown powder wants to stick to the glass of the measuring cup.

You should do your final water washes with distilled water to prevent that from happning.
It is very well explained both here on the forum and in all of my video.

 

[Oz]

Sweep it out of your glass carefully with an artists paint brush.

 

[qst42know]

I keep a brush in a bag for just such occasions. :mrgreen:

 

[butcher]

How I handle my washed powders,
After washing well in my reaction vessel.

The powders are transferred to small clean glass jar (amount of powder determines size with extra room for more washing solution) (the jar is weighed dry, weight written on lid for later reference when weighing dry powder).

The wet gold powder is transferred using a spray bottle from the reaction pot to this small clean jar.

This small jar is set on coffee mug warmer (small heating plate warmer), here I can do some more washing, of the powders, decanting solutions (after settling) with a pipette (small eye dropper), after I am satisfied with washing, I pipette out water till only very small amount remains this will evaporate on heating,

Before powders completely dry I will pick up small jar in one hand and bang it against the palm heel of my other hand, this will make gold form balls (may need to be done a couple of times during drying process), (this will also collect what gold that would may stick to jar normally).

When balls are dry they can be transferred easily to melting dish (or can be crushed to powder if I prefer another refining).

 

[lazersteve]

Here's an old post that gives step-by-step details:

Getting Gold powder out of a glass beaker

Steve

 

[Photobacterium]

Thanks everyone for the Education & Coaching !

I got it (the tiny bead, 0.3 grams) in my pocket now.


I was thinking about using wax (paraffin) to "scoop up" the gold in the measuring cup. Then putting the wax in the crucible & burning off the wax, but hopefully the small amounts of gold powder would stay in the crucible.

Good idea/ bad idea ?\


This time, I used a stick about 1/8" diameter to coax all the powder into one pile, in the measuring cup I used for precipitation, and then dumped it onto a piece of aluminum foil - I was looking for a material that wouldn't grab onto the tiny pieces of gold powder.

Then folded the alum. foil & let gravity assist me in transferring it to the melting crucible.

Then that went into the kiln.


I did use distilled water, but I probably used to much SMB. I saved the fluid I siphoned off. I found some 96% tin solder (Tin-Antimony) locally, I thought I would use that to make my Stannous Chloride to test that fluid. $6 vs. $30 shipped for 100 grams of tin powder from Sigma Aldrich.

Or is the pure tin a better deal in the long run ?

 

[Dr. Poe]

How I handle my washed powders,
After washing well in my reaction vessel.

The powders are transferred to small clean glass jar (amount of powder determines size with extra room for more washing solution) (the jar is weighed dry, weight written on lid for later reference when weighing dry powder).

The wet gold powder is transferred using a spray bottle from the reaction pot to this small clean jar.

This small jar is set on coffee mug warmer (small heating plate warmer), here I can do some more washing, of the powders, decanting solutions (after settling) with a pipette (small eye dropper), after I am satisfied with washing, I pipette out water till only very small amount remains this will evaporate on heating,

Before powders completely dry I will pick up small jar in one hand and bang it against the palm heel of my other hand, this will make gold form balls (may need to be done a couple of times during drying process), (this will also collect what gold that would may stick to jar normally).

When balls are dry they can be transferred easily to melting dish (or can be crushed to powder if I prefer another refining).

Thanks Butcher, I grabbed this post for my home PC files. I'm labeling it "Butcher's Balls". I used to call it "making gold dust bunnies". Your's is better.
Dr. Poe

 

[butcher]

Dr Poe, :lol: I like my little gold balls, they shine when heated.

Photobacterium, nice lil pretty button, I would keep other metals (like aluminum foil) from the gold, your going to a lot of trouble to get rid of metals, you do not want to add them back at last stages of the game.

 

[Harold_V]

Photobacterium, nice lil pretty button, I would keep other metals (like aluminum foil) from the gold, your going to a lot of trouble to get rid of metals, you do not want to add them back at last stages of the game.

What butcher said.
Learn to keep metals away from one another. It's well documented that atoms of gold migrate to other metals when in contact. Read The Metallurgy of Gold, Sir T.K. Rose

Harold