Sciencemadness Discussion Board

Using Chemistry to identify metals in solution

kadriver - 2-2-2015 at 08:40

Here is another video, step by step, on how to extract and refine Pure Gold from jewelers polishing sweeps. Part one of three (this video) only shows the prep and removing metals that are soluble in hot dilute nitric acid.

Part two of three shows the tests I perform to see what metals are in solution. It will be posted later today as the filming is complete and all I have to do is edit and post.

http://youtu.be/UZgIDRTJ_bQ

Any critical comments would be appreciated!

Thank you,
kadriver (Kevin)

Magpie - 2-2-2015 at 09:17

The video and text are very well presented. Maybe give the reader a little more time to read the full pages of text - I had to stop the video to read it all.

I'm surprised that Corning casserole dish holds up to the uneven heating on the hotplate and with the torch. Has it ever cracked on you?

I look forward to your remaining videos of this process.

Part 2 of 3 video

kadriver - 2-2-2015 at 13:36

Those pyroceram dishes are very tough. But I would not try to put one on an open flame.

I did break one once. I had about a kilo of wet cement silver in a large one to dry the silver.

I turned the heat up to high on my kitchen stove to get it warmed up and forgot about it.

About five minutes later I heard a sharp crack noise as it broke into many pieces.

Here is part two of three of the video;

http://youtu.be/7Srw0Z3CvN4

kadriver

Zombie - 2-2-2015 at 14:04

Very, very nice Vids.

I am impressed with your process, and looking forward to the third part.
Thank you for sharing this.

kadriver - 6-2-2015 at 13:28

Here is part three:

http://youtu.be/BEsN7Hy3_lw

Thanks for looking

kadriver

Zombie - 6-2-2015 at 19:56

That is absolutely COOL! I was going to ask if there is any profit after energy used, chemicals consumed, and I see at today's price per gram it is a bit above the break even mark.

It's just about the coolest process I have seen applied to a daily life kind of project.

You have a fan sir!

PHILOU Zrealone - 9-2-2015 at 11:35

@Kadriver,

Very cool videos.
I just want to point out that you use oxyacethylen welding blow-torch (flame heat 3000-3100°C) but it would be more convenient to use colder H2/O2 (flame heat 2000°C) or common welding torch (butane-propane/O2: flame heat 1950°C ... or better butane-propane/air: flame heat 1650°C).

Why?

Because you seem very concerned to keep and recover as much of your gold...

1°) Au (Gold) has a melting point of 1064°C and a boiling point of 2856°C --> you are above the boiling point what means some of your Au is lost in fumes.

2°) It is not wel known fact but Au being a noble metal, atomic interactions are relatively weak and it is in fact quite volatile when above the melting point...portions of it sublimes long before the boiling point is reached.
The hotter the heat, the stronger the sublimation is ... with a maximum when heat is at the boiling point. With that aspect Au ressembles Hg...heavy metal but volatile when molten...
So this is a second way to lose some gold from your process.

The best way to avoid this is to be on the cold side when performing the fusion of gold!


[Edited on 10-2-2015 by PHILOU Zrealone]