hey guys, i quartered some gold, and disolved it in nitric, and it completely disolved leaving the gold powder at the bottom, I weighed the gold powder and it yielded what i expected it to. Then I ran an aqua regia over it and it completely dissolved. I let it sit on the heat for a while hoping to neutralize it the best I could. Later I added urea mixed in water until it stopped fizzing, but then when I added the bisulfite it acted like it wasn't neutralized. So I added more urea and it would fiz more, I kept adding it until it completely stopped fizing, and again when I added the bisulfite it acted like it wasn't neutralized. Finally on my third try i managed to completely neutralize it. Then I dropped all the gold out of it, at least it appeared that i did. It wouldn't show any gold on the stannous chloride. After drying my gold I came up about twenty percent short. I have saved all my fluid from the process. Later when I put the fluid on stannous chloride it shows there to be no gold, but after about five minutes It turns black on the paper towel. I've added bisulfite and can't get any gold to drop out. Does anybody have any idea where the gold could have gone? Is it possible the gold is still trapped in the liquid somehow?
lost gold somewhere in the process
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Several possibility's, the gold weighs less because more base metals were removed, in the first refining. Or there could be some gold still in solution with free nitric acid keeping it dissolved, urea is not the best way to De-NOx your solution (I think using urea is just dangerous and a waste of good fertilizer), also the stannous chloride test will not show if there is gold if you still have free oxidizer in solution, the stannous test cannot reduce the gold, too much SMB used can also give a dark brown reaction in a stannous chloride test.
The urea can also add contaminates to your solution, I will not go into deep detail of all of the reasons I say forget using urea it is a bad choice in my opinion.
Look for other methods to deal with the oxidizer next time , and use your urea for fertilizer, you will learn more about this by studying the forum, and Hoke's book:
Using minimum nitric acid to begin with.
using the three time evaporation process, with HCl to wet, and a few drops of sulfuric acid.
Leaving a tad bit of undissolved gold even with heating and concentration.
Using an added gold button to remove free nitric from solution.
Using sulfamic acid to De-NOx.
At this point you could try to denox the solution again through the three evaporation process if free nitric is holding gold in solution, or you can cement it out of solution with copper.
The urea can also add contaminates to your solution, I will not go into deep detail of all of the reasons I say forget using urea it is a bad choice in my opinion.
Look for other methods to deal with the oxidizer next time , and use your urea for fertilizer, you will learn more about this by studying the forum, and Hoke's book:
Using minimum nitric acid to begin with.
using the three time evaporation process, with HCl to wet, and a few drops of sulfuric acid.
Leaving a tad bit of undissolved gold even with heating and concentration.
Using an added gold button to remove free nitric from solution.
Using sulfamic acid to De-NOx.
At this point you could try to denox the solution again through the three evaporation process if free nitric is holding gold in solution, or you can cement it out of solution with copper.
metatp
Well-known member
I like putting a small piece of gold in the solution. It works better than the Urea.
Tom
Tom
