What happened with this gold foils?

[cosminlala]

Hi. I've just melted some foils recovered from fingerboards. Why did it come out like this? Maybe i added too much borax?... I have to mention that i didn't refined the foils and i melted it in a graphite crucible in a home built furnace with MAPP gas torch

 

[glorycloud]

Well, I am not sure why you might have decided to go straight to melting your gold foils. The process to
turn the foils into Auric Cloride using HCL / CL is much discussed here as is the process to drop
the gold from the solution using SMB. As is the process to "clean" the gold powder after the drop,
dry it and THEN melt it in a crucible with borax.

I hope that someone here can help you as it surely looks like a mess to me. :shock:

 

[yar]

Looks like you had a lot of foreign materials mixed in with the foils. I have never used a graphite crucible but I do not believe you use borax or any flux when using graphite. Maybe those with more knowledge will give their opinions.

 

[heliman4141]

Hi. I've just melted some foils recovered from fingerboards. Why did it come out like this? Maybe i added too much borax?... I have to mention that i didn't refined the foils and i melted it in a graphite crucible in a home built furnace with MAPP gas torch

I hope you are more informed about safety then refining or recovery of PMs from what im seeing.
glorycloud told you the correct path ....................but, that is hindsite now.
My advice is set it aside & start reading everything you can right here on this website. Download Hokes book & begin at pg.1 and read it all..............in the meantime use the searchbar here also.
I do not know if you can salvage all the PM in that crustmess, maybe it can be crushed to a powder then reclaimed using hcl/cl & filtered a few times.
Im stressing reading the safety section here first before you even consider recovering anything at this point.
This is a deadly serious craft/hobby, one mistake can cost you your eyes or lungs or worse. As an example read what will happen when hcl, bleach, & ammonia is combined, there are a thousand ways to mix incompatable simple chemicals. And these 3 seemingly safe chemicals are used all the time in PM recovery....... just never ever combined. One of many examples that one needs to know about before refining anything.
You need more education about everything you touch, heat, mix, whatever.. before proceeding so you will already know the outcome well in advance.
Ive learned a mountian of information here & can now refine my Gold but the most importaint thing I learned here was all the safety info. No Gold is worth injury & from what im seeing with the lack of the knowlege of very simple recovery/refining technics not being used shows me a lack of safety knowlege as well. I don't mean to sound harsh, just am pushing the safety aspect to you for your own well being.
Look up lazersteves videos here, he has a great one on glazing new crucibles you can view, so you know how much Borax to apply etc...in the future.

Dave

 

[Harold_V]

It's pretty simple. You didn't melt the foils, although you did melt them somewhat. What I'm seeing is that you melted the foils where they were not in intimate contact with the carbon, but once they were, you didn't have enough heat to melt them further. You could have avoided that problem by melting with an oxy torch, even with natural gas, or by switching to a melting dish made of a refractory material. It won't dissipate the required heat as quickly.

Do as you've been advised. Get educated in regards to processing, and learn that melting requires adequate heat. When you try to melt on a carbon substance, it conducts heat away so quickly that you most likely can not achieve your goal.

Harold

 

[joekbit]

I agree with Harold on this one. I was going to say that your foils were still in suspension. Harold on the other had hit it with the correct words. They did not melt all the way. With the Borax bubbling away they simply wrapped themselves around the gas bubbles within the borax. Hence my words "still in suspension" . Keep it, your gold is still there. You will have to crush it, pulverize it.

Then step back to the use of hydrochloric and Nitric acid to dissolve the gold. Filter and rinse. and reprocess the material from the filter again. If you want to ensure you have recovered all the gold you will need to do this until your unfiltered solution test negative for gold.

Lesson hard learned, I've been there. At this time I'm not even going to drop my gold from my solution. It can stay there until I have the proper equipment to melt it down. Having said that I'm going to attach something I am presently studying. It will also be placed in the equipment forum. Its how to select your crucible based on what your using it for and the type of furnace or melting equipment you have.

 

[bswartzwelder]

I'll bet Harold will sleep better tonight.