What in God's green earth did I do now?

Gold Refining Forum

Help Support Gold Refining Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
So the color could be colloidal gold or tin. The tin could have come from a repair or resizing and the use of low grade solder/braze material. Any idea what would put the gold into solution as a colloid with known good chemicals? Does tin have a property that could put some gold into solution?
 
I did stannous tests on it and it was negative for gold but how is it possible that the first 2 washes I did were completely fine but the rinses after were infected with whatever it was? Is it possible that it was a delayed reaction? Or that it took more nitric to get out after dissolving the copper and silver? I mean my bar came out looking good with no signs of contamination though.
 
I don't think stannous will test right for gold as a colloid. I know SMB won't drop it.
 
anachronism said:
It's fine. Honestly don't worry or panic. 8) 8) 8)

I don't think of it as worrying so much as was it avoidable. Honestly, for me, I would be at the point of "let's start the next batch". But, curiosity is always there.
 
Shark said:
anachronism said:
It's fine. Honestly don't worry or panic. 8) 8) 8)

I don't think of it as worrying so much as was it avoidable. Honestly, for me, I would be at the point of "let's start the next batch". But, curiosity is always there.

Aye but given the title of the OP - I would suggest worry was there mate haha
 
Shark said:
anachronism said:
It's fine. Honestly don't worry or panic. 8) 8) 8)

I don't think of it as worrying so much as was it avoidable. Honestly, for me, I would be at the point of "let's start the next batch". But, curiosity is always there.

I'll be doing another batch in a week or so, so I guess we'll see if it was a janky batch or it was the water 🤷‍♂️
 
There is a chance that Tin can go into solution in heavily chlorinated town water from the Tin based Solder used on water pipes. Whether its enough to turn a solution purple is another question.
Your solution looks pretty though, whatever its from :lol:

Cheers Wal

Edit.. I reread the post, since you used distilled water this doesn't apply
 
How well do you wash your beakers before each reaction? Is it possible your nitric source got contaminated? What I suspect is like fish said a cheap repair solder containing tin was used somewhere in the repair or alloy itself. I could possibly been in the gold alloy as well. The beaker or your nitric source contained HCL or some other contaminate that would create AR. When digesting the inquart, stannous and gold chloride were created. Voila, purple solution.

There would have only needed to be a very small amount of tin present to do that. In fact I would say an extremely small amount to get that pretty purple color you got and not a super dark nearly black hue. Think about what would happen if you put one drop of stannous in a beaker of gold chloride. This would also explain why there was no contamination in the bar. It would have been cool if you had filtered the particulate and roasted it.
 
goldenchild said:
How well do you wash your beakers before each reaction? Is it possible your nitric source got contaminated? What I suspect is like fish said a cheap repair solder containing tin was used somewhere in the repair or alloy itself. I could possibly been in the gold alloy as well. The beaker or your nitric source contained HCL or some other contaminate that would create AR. When digesting the inquart, stannous and gold chloride were created. Voila, purple solution.

There would have only needed to be a very small amount of tin present to do that. In fact I would say an extremely small amount to get that pretty purple color you got and not a super dark nearly black hue. Think about what would happen if you put one drop of stannous in a beaker of gold chloride. This would also explain why there was no contamination in the bar. It would have been cool if you had filtered the particulate and roasted it.

I clean the everything throughly with soap and water then rinse with distilled water every time I'm done with them. It was very interesting though, hopefully none of my chemicals are contaminated
 
One way contamination can travel from one beaker to another is when you have HCl and nitric in beakers beside each other. Both acids can easily go up in the air and be absorbed by nearby solutions. I've seen beakers with silver nitrate getting cloudy at the surface from silver chloride forming at the surface.

Silver chloride with an acidic silver nitrate solution (ie free nitric acid) shouldn't turn purple from light (sunlight) because the purple color is metallic silver, the free nitric acid should dissolve it immediately and turn into white silver chloride or colorless silver nitrate again.

I don't have a good explanation of the color change. But when I saw the pictures I thought that the acid was quite cloudy, almost as there were silver chloride or tin suspended in the solution.

Göran
 
g_axelsson said:
One way contamination can travel from one beaker to another is when you have HCl and nitric in beakers beside each other.

When I was in high school, I worked as a chemistry assistant in the back room mixing all the solutions other students would use in class. We learned to work very accurately and cleanly. We referred to nitric acid as a "creeping" acid. Even when poured cleanly into a beaker, with no splashes or drips, if we picked the beaker up later we could end up with yellow fingers. I didn't understand the mechanism then, so we just thought of the acid as being able to creep up and over the edge of the beaker.

Dave
 
FrugalRefiner said:
g_axelsson said:
One way contamination can travel from one beaker to another is when you have HCl and nitric in beakers beside each other.

When I was in high school, I worked as a chemistry assistant in the back room mixing all the solutions other students would use in class. We learned to work very accurately and cleanly. We referred to nitric acid as a "creeping" acid. Even when poured cleanly into a beaker, with no splashes or drips, if we picked the beaker up later we could end up with yellow fingers. I didn't understand the mechanism then, so we just thought of the acid as being able to creep up and over the edge of the beaker.

Dave

I always end up with yellow stains on my gloves no matter how hard I try to be careful. I completely understand lol
 
FrugalRefiner said:
g_axelsson said:
One way contamination can travel from one beaker to another is when you have HCl and nitric in beakers beside each other.

When I was in high school, I worked as a chemistry assistant in the back room mixing all the solutions other students would use in class. We learned to work very accurately and cleanly. We referred to nitric acid as a "creeping" acid. Even when poured cleanly into a beaker, with no splashes or drips, if we picked the beaker up later we could end up with yellow fingers. I didn't understand the mechanism then, so we just thought of the acid as being able to creep up and over the edge of the beaker.

Dave
I have experienced this early on thinking a beaker I used to measure out Nitric Acid was OK to handle without gloves one I carefully poured out without spilling.

Now I never handle a beaker without gloves until it is washed and dry and I am putting it away at getting it out for reuse.



Sent from my SM-G950U using Tapatalk

 
Back
Top