Unable to precipitate gold

[Martijn]

So after heating for about 3 hours and letting it settle overnight this is now what I am left with.

Should be good to give it another try.
Measure if pH is still one. Then chill and filter until crystal clear and add then some predissolved SMB.
This will first disappear, turn from yellow to clear, and then into brow. In time it will fall as a thin layer on the bottom.
Expect about 0.2 or 0.1 grams of gold from 100 grams of fingers. Very little.

 

[Israel2]

Hi all, I am new to this forum so hello . I am hoping that someone will be able to help me. I have followed the instructions from this post Gold Recovery Correctly exactly. I tested the gold solution as described, which instantly turned black. When it came to adding the sodium bisulfite there was no reaction, the liquid remained yellow, I continued to add sodium bisulfite hoping for a reaction however this didn’t happen and I overloaded it . I ended up with roughly a 1 cm layer of sodium bisulfite, not knowing what to do I added more hydrochloric acid. I now have roughly 4cm of crystals in the liquid. The solution still tests positive for gold but I don’t know how to extract the gold.

Any suggestions/help would be greatly appreciated!

Thanks,
Malc

Hi I am new here i think I have the same problem I have added sodium metabisulfite, but it didn't resolve. It turns black and then back to yellow, I have added too much sodium metabisulfite and its now sitting under the beaker. Its still reacting when I add it In the reaction, what should I do please

 

[FrugalRefiner]

It sounds like you used too much oxidizer (nitric acid?). So, when the metabisulfite reduces the gold to metal (that's when it turns black), the excess oxidizer dissolves it back into solution again.

See When In Doubt, Cement It Out.

Dave

 

[Yggdrasil]

Hi I am new here i think I have the same problem I have added sodium metabisulfite, but it didn't resolve. It turns black and then back to yellow, I have added too much sodium metabisulfite and its now sitting under the beaker. Its still reacting when I add it In the reaction, what should I do please

I will ask one question more.
How did you make your AR?

 

[Shark]

Did it look like this? This was an experiment by me to see the results of to much bleach in hydrochloric so I would be able to actually see it as it happened.

 

[goldshark]

Hi I am new here i think I have the same problem I have added sodium metabisulfite, but it didn't resolve. It turns black and then back to yellow, I have added too much sodium metabisulfite and its now sitting under the beaker. Its still reacting when I add it In the reaction, what should I do please

Did you use AP, or AR? Sounds like you over dosed the Nitric, if you went the AR route. Boil to syrup, or use Sulfamic to DeNOX. If you boil to syrup, you will need to rehydrate it with HCL. This s covered many times on GFR. Research before you attempt the procedure.

 

[FrugalRefiner]

Did you use AP, or AR? Sounds like you over dosed the Nitric, if you went the AR route. Boil to syrup, or use Sulfamic to DeNOX. If you boil to syrup, you will need to rehydrate it with HCL. This s covered many times on GFR. Research before you attempt the procedure.

You do not want to boil to a syrup, you want to evaporate to a syrup. Boiling will cause losses. As the bubbles from boiling pop at the surface, they will cause tiny droplets of solution to be ejected from the container. Evaporate at a temperature below boiling.

Dave

 

[Shark]

Try using a filter paper over your AR solution while reducing it with heat. Add a drop of stannous chloride to the filter paper after your done. The results may surprise you.

 

[goldshark]

You do not want to boil to a syrup, you want to evaporate to a syrup. Boiling will cause losses. As the bubbles from boiling pop at the surface, they will cause tiny droplets of solution to be ejected from the container. Evaporate at a temperature below boiling.

Dave

In my rush to respond, I meant to say evaporate, but boil was a faster response. Yes, evaporate, not boil, sorry.

 

[FrugalRefiner]

No worries. Even Hoke used the word boil incorrectly a couple of times when it should have been evaporate.

Dave

 

[anthonyulo8]

Hi I am new here i think I have the same problem I have added sodium metabisulfite, but it didn't resolve. It turns black and then back to yellow, I have added too much sodium metabisulfite and its now sitting under the beaker. Its still reacting when I add it In the reaction, what should I do please

Hi,

I currently work in a gold refining company and we use sodium metabisulfite. From my experience, we use urea before treating it with sodium metabisulfite. Without urea, we couldn't precipitate the gold. Also, you have to let it react properly (by stirring or agitation) with sodium metabisulfite. We add metabisulfite slowly while letting it stir. Then again, like what others are saying, you need to review the AR you are using. Make sure that it is fully dissolved in AR with enough reaction time.

Note: This is the process that we are using. There may be other ways to use sodium metabisulfite that I am not aware of so correct me if I'm wrong.

 

[Yggdrasil]

Hi,

I currently work in a gold refining company and we use sodium metabisulfite. From my experience, we use urea before treating it with sodium metabisulfite. Without urea, we couldn't precipitate the gold. Also, you have to let it react properly (by stirring or agitation) with sodium metabisulfite. We add metabisulfite slowly while letting it stir. Then again, like what others are saying, you need to review the AR you are using. Make sure that it is fully dissolved in AR with enough reaction time.

Note: This is the process that we are using. There may be other ways to use sodium metabisulfite that I am not aware of so correct me if I'm wrong.

We are not very fond of using Urea, since it is not fully decomposing the Nitrates and NOx.
And Urea can under some conditions form explosive compounds.
The best is not use too much Nitric, next best is to use Sulfamic acid.
The reason for the problems of precipitating is that the excess oxidizer makes the Gold redissolve immediately.