Can't get gold to dissolve

[jeneje]

Ken using your weights and allowing the material to be 1/2k under assay you should be looking for 22 grams plus,

nick, that is what i'm really thinking is about 22 grams anything less should be in the pot. I saved everything so it not far away. :lol:

Thad after doctor visit this morning i am going to start the re-refinement and hope for the best. Still strugling about which methord to use - HCL/Cl or AR. leaning towards AR, just hate to denox :roll: we will see! :lol:

Ken

 

[tek4g63]

Ken,
If you work slow and add the nitric in very small increments allowing much time to pass before adding more and stirring several times between additions. You can avoid the denox process. Of course it takes some practice to be able to tell when to add more and not add too much.

That's how I do it and after the last addition, when all gold is dissolved, I always keep a previously refined button on hand ( known weight ) and I drop it in the solution. leave it on heat for and hour or two stirring occasionally, then remove the button rinse and dry then weigh the button to see if it lost any mass.

It took me many trays not to lose any mass from the button, but its an awesome feeling the first time you see that your button is still all there.

 

[jeneje]

Ken,
If you work slow and add the nitric in very small increments allowing much time to pass before adding more and stirring several times between additions. You can avoid the denox process. Of course it takes some practice to be able to tell when to add more and not add too much.

That's how I do it and after the last addition, when all gold is dissolved, I always keep a previously refined button on hand ( known weight ) and I drop it in the solution. leave it on heat for and hour or two stirring occasionally, then remove the button rinse and dry then weigh the button to see if it lost any mass.

It took me many trays not to lose any mass from the button, but its an awesome feeling the first time you see that your button is still all there.

Thad i am using AR to do this refinement. I started with 200ml HCL and added 1/2 eye dropper HNO3 on very low heat with watch glass. It doing great so far - now starts the waiting game. I figure a few hours and it should be dissolved.

I don't have any melted buttons...but i do have 12grams of double refined gold in powder form i can use, if that will work. If not its to the denox stage.
Ken

 

[tek4g63]

Ken,
That would work. The problem is whatever gold powder didn't dissolve would have to be filtered out or otherwise reclaimed. And that would be troublesome.

Is there anyway that you could melt that gold into a button?

Just take it easy on the nitric additions and when there is almost no powder in the vessel, but you can still see a little gold powder, stop there and raise the heat a bit. Do not boil! Just make it steam, add nothing and see if the last powder dissolves. If it does not, then your solution is free of nitric and maybe you can add that tiny bit of powder to the next batch? This is provably not the best way and I'm sure others will be more than happy to correct me if I'm wrong.

I wish you the best! Can't wait to see the next pictures.

 

[jeneje]

The re-refine is going slow i am about half way - should be done tommorow. After addition of HNO3 i wait untill it completly quicks reacting, even with mild heat it is still slow but it will be worth the wait :mrgreen: The color is a golden orange and stannous test are very dark purple, almost black in color.

Ken

 

[jeneje]

Well i have completed the dissolution of the gold for the second time. As Thad recommended i left some powder in the AR and will catch it - and add it to the next batch. Here is a pic of the golden orange color. Tomorrow i will try to drop with SO2 gas.

Ken

 

[butcher]

You have come a long way, looking good.

 

[tek4g63]

Looking great!

I love it when the solution is so saturated with gold that it's orange.

 

[jeneje]

Looking great!

I love it when the solution is so saturated with gold that it's orange.

Yeah it looked good. I just dropped the gold by adding SMB, We will know after while what is there. Hoping for alot but will take what it gives :mrgreen:

Ken

edited for pic, 30minutes after addition of SMB.

 

[jeneje]

You have come a long way, looking good.

Thank you Butcher, its all due to members like you who are willing to help others in their search for learning.
Ken

 

[jeneje]

Just weighted the finial amount, it came to 21.5 grams after washing and drying. Still have some in stock pot and filters.

Ken :mrgreen:

 

[glondor]

Excellent job. The powder looks good. Study up on the melting process and show us the button.