Where did I go wrong?

[Alabama938]

So I used poor man’s AR to dissolve about 20 CPU chips. My source of nitrate was potassium nitrate, it took nearly 80 g to dissolve all of the metal into solution. I filtered it and it was dark, with yellow bubbles and fairly clear on transillumination. The amount of solution after washing the chips and filter thoroughly with distilled water overwhelmed a single beaker so I split it between two…

I added a small amount of SMB and there was a quick evolution of some reddish bubbles, which made me concerned there was a significant amount of nitrates… I added half a teaspoon of sulfamic acid powder, to a slightly less than half full 2 L beaker and it immediately overflowed into my catch basin, ugh

After cleaning everything up the next spoonful had a much more mild reaction and the third had virtually no reaction, still sulfamic. So I stirred everything well and when I went back an hour later everything looked the same still testing positive for gold with Stan chloride solution.

Because of the overflow issue before I decided against adding more liquid and added SMB as a powder and just continued to get red bubbles after four or 5 spoons nothing had happened anything like the NileRed or sreetips video examples

Instead of adding a bunch of extra things or pounding it with SMB I figured I would just add some copper wire to cement everything out right? I did not dilute the dirty chloroaurate acid solution, I realized that could have been one of my mistakes. Also I’m concerned that my potassium nitrate was used in excess even though I tried to be very stingy.

Honestly felt pretty embarrassing to have a foam over and the gold not drop despite trying to follow all the steps and conditions appropriately. I let everything settle overnight and this morning there was still a positive stannous, pretty strongly positive but also it did not turn positive immediately it took about seven or eight seconds in a white spoon, which seems different than I have seen on a lot of videos showing the process.

I guess I would like to know your opinions on what I could have done differently or better, or if there’s a save besides cementation.

Roll Tide

 

[Alabama938]

So I just got home from work and checked on everything and these beakers now reek of sulfur dioxide, gold test still looks positive, image attached. It’s really hard to tell if there’s anything settled out at the bottom, I do have some more SMB will adding an over abundance of that screw up the cementation if I go that route I’m in no rush

 

[butcher]

That does not look like a positive test for gold, that looks like reduced copper ions in a stannate solution (often called a false-positive reaction).

Brown color with no purple = No gold ions dissolved in solution.

Gold will give a purple or violet color, very concentrated the dark violet may appear black (diluting it will then show the pretty purple color of metal gold in a stannic chloride solution.

You can also use copperas to see how your solution reacts to that test, and compare that with your stannous chloride test.

If you still think you may have gold in the solution, you can always use a clean bar of copper, and gold will show up as the gold clings to the copper and is reduced from the solution as it cements out.

 

[FrugalRefiner]

I was just starting a response, but saw that butcher already posted. I agree with butcher.

Dave

 

[Alabama938]

That same test allowed to sit it looks like this, is that still a false positive, Or is that the black you’re talking about. Couldn’t find Copperas At the local hardware store so I’m gonna have to order that. Thanks again

 

[butcher]

A bit hard for me to distinguish the color from looking at the picture, You have a better view, if it is purple then it is positive for gold.

White salt of silver can turn a violet to a black color after exposure to UV sunlight, you may see this when you filter a chloride solution and wash the white salts of free acid, you should not see this in a test for gold using stannous chloride (remember silver ions become insoluble in a chloride solution) although silver chloride is very fluffy and hard to settle which can take some time (sometimes up to overnight, so if you did not let the silver chloride settle before taking your chloride sample to test it for gold then there may be a possibility of picking up some of the silver chloride salt in the sample...

It could also be colloidal gold (violet color) showing late.
which is very likely.

What does the test look like with a crystal of copperas in a white spoon (do you get a brown ring of precipitated gold?

I cannot tell much from the picture at this point, someone else may see what I cannot.

 

[Alabama938]

Yeah it’s definitely hard to tell comparing what I can see, because it it dries out it’s really obviously a violet color on the filter paper from last evening, but the test after precipitation have this more black look… I went ahead and filtered the solution to start cementing it and the results looked pretty promising. You can see my shiny copper waiting in the wing. This picture was before any water or HCL washings through the funnel.

I’m thinking I might redissolve this filter paper and material in real AR as opposed to trying to torch it.

Thx

 

[butcher]

You may also consider using HCl and sodium hypochlorite (bleach) as an option, easier than aqua regia.

With the poorman's aqua regia, you may also consider the filter paper could have captured a nitrate salt.

Torching the filter paper could be a mistake, if it held chloride salts you could put some of your gold into the air with the fumes or smoke if it is gold you surely want to re-refine the dirty gold, to high purity and not leave the job half done...

I do not know if its the picture or my eyes but if that is gold it must have come from a dirty soup, or my eyes are worse than I thought, looks like a filter from a gold recovery operation (from a dirty solution loaded with base metals than a gold refining operation.

 

[Alabama938]

So I dissolved the filter paper in real AR, took 9ish mL 68% to visually stop reacting with a small gold bead in there for an hour. Cooled in ice bath (cause I was excited), filtered, tried a small spoon SMB and now it finally looked like it was supposed too, right down to the violet stannous test going colorless after a little over 80g SMB.
That was so fulfilling, I’ll post a picture of the washings tomorrow and hopefully a bead, some seriously cool stuff gentlemen