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Having trouble dropping gold from solution

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DelawareDave

Member
Joined
Jan 19, 2025
Messages
7
Location
Delaware
Having some issues with dropping gold out of solution. About 3 months ago I dissolved about 4 grams of gold with AR, that solution sat covered till about a week ago so very little evaporated. Attempted to drop the gold with SMB, put quit a bit in there. On that note my SMB was probably 3-4 years old and a solid lump that I had to break up. Thought maybe the SMB was too old so I ordered some fresh stuff. Added that till it became super saturated and still nothing dropped. For a last ditch I threw some zinc in there just to try and drop everything and start the refining process over again. After 2 days of sitting there is some sediment at the bottom and the whole solution turned brown then settled with a clear liquid. But every time I test the liquid with SnCl the test spot turns mud brown like there is a bunch of gold still in solution (SnCl is fresh, just made it last week)… any help would be great.
 
Having some issues with dropping gold out of solution. About 3 months ago I dissolved about 4 grams of gold with AR, that solution sat covered till about a week ago so very little evaporated. Attempted to drop the gold with SMB, put quit a bit in there. On that note my SMB was probably 3-4 years old and a solid lump that I had to break up. Thought maybe the SMB was too old so I ordered some fresh stuff. Added that till it became super saturated and still nothing dropped. For a last ditch I threw some zinc in there just to try and drop everything and start the refining process over again. After 2 days of sitting there is some sediment at the bottom and the whole solution turned brown then settled with a clear liquid. But every time I test the liquid with SnCl the test spot turns mud brown like there is a bunch of gold still in solution (SnCl is fresh, just made it last week)… any help would be great.
Brown is usually considered false positive.
I think you need to test the pH and then add water to dissolve as much salts as you can.
Then filter well, acidify with HCl and test again with Stannous and pH.

This is how Stannous looks for Gold

1740258002232.png
 
Roughly 4 parts HCL to 1 part HN03
That is way to much Nitric.
Add HCl so it covers what you have and then add Nitric as needed, drop by drop should do here.
In this case between 2-5 mls.
Then you need to deNOx it to remove excess Nitric, if not the Gold will redissolve.
Use Sulfamic acid for this.

Your current problem is that you have way too much SMB added.
So dissolve as much as you can with adding some liquid.
Adding HCl might solve your issues alone.
How much liquid do you have now?
 
That is way to much Nitric.
Add HCl so it covers what you have and then add Nitric as needed, drop by drop should do here.
In this case between 2-5 mls.
Then you need to deNOx it to remove excess Nitric, if not the Gold will redissolve.
Use Sulfamic acid for this.

Your current problem is that you have way too much SMB added.
So dissolve as much as you can with adding some liquid.
Adding HCl might solve your issues alone.
How much liquid do you have now?
I said about 4:1 since that’s the general ratio for AR. I actually Covered with HCL and dripped in HNO3 like you said. Volume wise originally was less then 100 ml, but after the frustration of the gold not dropping, and adding HCL & distilled water to try an dissolve the excess SMB I ended up almost 500 ml
 
I said about 4:1 since that’s the general ratio for AR. I actually Covered with HCL and dripped in HNO3 like you said. Volume wise originally was less then 100 ml, but after the frustration of the gold not dropping, and adding HCL & distilled water to try an dissolve the excess SMB I ended up almost 500 ml
I think the best now will be to dissolve as much as you can of the crystals so all is liquid.
Then add some HCl so it is acidic and put in a slab of Copper to cement it out.
Then you can take the cement and dissolve in HCl/pool chlorine and drop it with SMB.
 

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