Melting scrap gold with a digital furnace.

[jhop1994]

Hi everyone my name is Jason, I recently took an interest in refinement and have been patiently building up my confidence to work with chemicals. Though first I’ve started using cupellation as a process of refinement. Anyway, I started to melt down these larger 250-300 gram ingots of scrap gold I got on eBay from some Middle East country where it was described as melted down computer pins and such. About a little less than 15 minutes into the melt, the material(won’t even call it gold at this time) starts giving off weird colors followed by fumes, I didn’t even approach. I keep my clear of it by turning off the furnace and letting it cool down a bit before pouring. Like 10 minutes. An still copious amounts of fumes are coming off of it, I pour it into a deep plastic water bucket. Unfortunately I had confidence that the water would cool it down, it did not do it quick enough before melting through and watering my work area. After all is cleaned up I put the rest of the weird scrap gold away. Examining the crucible it was covered in a yellow chalk like powder. Never seen anything like it when melting silver. This was my first attempt at melting scrap gold.
I took some pictures, was hoping someone can offer some guidance on what happened or what was going on.

-Jhop

 

[Palladium]

I know you don't want to hear this, but you got scammed.
Zinc and copper make a nice brass look like gold. What you are seeing is more than likely zinc vaping off because of it's low vapor temperature. Metal fume fever is next if you breath it. The material is worthless.

 

[jhop1994]

I know you don't want to hear this, but you got scammed.
Zinc and copper make a nice brass look like gold. What you are seeing is more than likely zinc vaping off because of it's low vapor temperature. Metal fume fever is next if you breath it. The material is worthless.

There is nothing I was more pleased to have read than your statement Palladium, it was invaluable experience for me. Thank you for that timely response. I remember reading it a few days an didn’t get around to replying cause I felt like when I spoke next it would be for more help. Alas that is what I am here for, switching this thread is not in my power but I have start chemical refinement using a aqua regia of 1 part nitric 3 part Hcl I simply worked with gold etched plates and cups easy stuff just soaked it in the aqua regia. I use urea Prills to lower the ph and when it stops foaming I thought it was okay so I added smb and I get thick clouds of brown vapor and what I was expecting for a quick process turns into this process where the beaker and the solution is getting hotter. Eventually I stop adding smb and switch back to urea, it reacts again. I am starting to think that I didn’t properly use enough urea after reading some posts from others. Though after adding more urea thinking it is good, I switch to smb which finally I get a color change in the aqua regia but soon I have this weird foam that has almost turn solid, it literally has to much weight. Plus there is crystal like specks at the bottom instead of a brown or red mud. I waited patiently for this moment and thought I did everything right but I need more guidance knowledge. If you have any insight I am asking sincerely or if you can direct me to a nice post with similar issues I would appreciate the assistance.

 

[Yggdrasil]

One lesson learned, which is good

But why not read and study before you dive into the
next mess?

First and foremost, do not use AR or other PM dissolving techniques if you are not to dissolve ALL metals.
The PMs will just cement out on the base metals.

Do not use Urea, which you already would know
if you studied the forum.
Use Sulfamic acid which will convert the Nitric to Sulfuric ​acid, simply spoken.

The brown fumes are most likely a little gold redissolving in the excess Nitric the moment it precipitates.

 

[jhop1994]

One lesson learned, which is good

But why not read and study before you dive into the
next mess?

First and foremost, do not use AR or other PM dissolving techniques if you are not to dissolve ALL metals.
The PMs will just cement out on the base metals.

Do not use Urea, which you already would know
if you studied the forum.
Use Sulfamic acid which will convert the Nitric to Sulfuric ​acid, simply spoken.

The brown fumes are most likely a little gold redissolving in the excess Nitric the moment it precipitates.

Hey, I really appreciate this next lesson you had to teach me. Thank you for your help, I actually finally made it to the end game goal this time. Admittedly it wasn’t easy, I used a lot of excess nitric and muriatic acid. I’m the beginning solution, was definitely a dumbass and didn’t read enough. Though I learned what denoxing was and have become familiar with the process of “add only what you need”. Anyway I am so thankful for your help. I wanted to share my small success with you cause of your valuable help in it.

 

[FrugalRefiner]

That's a nice sized piece of gold, and the color looks good. You were close to getting a button. Insulate your melting dish to try to keep the heat in.

Dave

 

[g_axelsson]

Nice gold and nice attitude. You will learn a lot and accomplish more in life with that mindset. Congratulations!

Göran