AR solutions

[Jimbriese]

Hello all so just a quick question as of right now I keep all my waste separate until after I cement with copper. Then they get combined to cement with iron and adjust PH.
So my question is I have a batch of AP waste that my gold went into solution copper would not cement out so I added nitric to dissolve all gold and then dropped with copperas. Went good until I went to boil in hcl to clean gold and some went back into solution not big deal made AR and this time I dropped with SMB. So can I just combine the two waste or will the copperas and SMB combine and cause other issues? My thought was if there was still some gold in the very dirty ap batch the extra SMB in the second waste stream might help it to come out of solution before cementing with copper.

And yes the gold was confirmed with stannous test in ap.

 

[Geo]

SMB and copperas together does not cause adverse reaction. As a matter of fact, I often use the two together if I am having a difficult drop. I use SMB first. Any small amount of excess nitric acid slows the drop or delays it. I add a small amount of ferrous sulfate and pretty much forces the drop.

 

[Jimbriese]

Thanks i know enough about chemistry to not mix anything until I know what the results are.

 

[dpgold]

I wonder what is the purpose of adding water after AR reaction is complete, how much water has to be added and when? Should it be distilled or regular tap?

 

[butcher]

A high concentration of chlorides can keep some of the silver in the solution as AgCl2, diluting a concentrated solution with three parts of water the silver in the dilute chloride solution can then precipitate as AgCl.
Allowing the solution to settle overnight and the solution becomes clear before carefully decanting (pouring off) the solution from undissolved silver chloride and filtering the liquid.
Ice can also be useful as the colder solution helps and as the ice dilutes the solution.
A few drops of sulfuric acid can help to remove lead from the solution.
Tap water is normally not a problem for solutions containing chlorides.

 

[dpgold]

A high concentration of chlorides can keep some of the silver in the solution as AgCl2, diluting a concentrated solution with three parts of water the silver in the dilute chloride solution can then precipitate as AgCl.
Allowing the solution to settle overnight and the solution becomes clear before carefully decanting (pouring off) the solution from undissolved silver chloride and filtering the liquid.
Ice can also be useful as the colder solution helps and as the ice dilutes the solution.
A few drops of sulfuric acid can help to remove lead from the solution.
Tap water is normally not a problem for solutions containing chlorides.

Thank you, the addition of water should be done before denoxing? It should be done in this order? :
First I filter the AR, use water to wash the filter and further dilute up to three parts.
Decant and filter the silver chloride
Add a bit of sulfuric to precipitate any lead and filter
Denox and precipitate

 

[4metals]

Often if you are carefully adding Nitric Acid only as needed, you will have little excess when everything dissolves. If that is the case, as Chris (Goldsilverpro) often said, the 3x dilution with water is all that is needed. You can skip the urea.

So…..assuming you didn’t over add nitric, chill the solution, because the ice will limit the solubility of the Silver Chloride, then add a few ml of sulfuric, then filter once. Then add enough water to equal a 3x dilution and drop the gold.

Any small amount of nitric remaining will re-dissolve gold as it drops and soon be exhausted, allowing complete precipitation.

The trick to doing it this way is not to add too much nitric to begin with.

 

[dpgold]

Often if you are carefully adding Nitric Acid only as needed, you will have little excess when everything dissolves. If that is the case, as Chris (Goldsilverpro) often said, the 3x dilution with water is all that is needed. You can skip the urea.

So…..assuming you didn’t over add nitric, chill the solution, because the ice will limit the solubility of the Silver Chloride, then add a few ml of sulfuric, then filter once. Then add enough water to equal a 3x dilution and drop the gold.

Any small amount of nitric remaining will re-dissolve gold as it drops and soon be exhausted, allowing complete precipitation.

The trick to doing it this way is not to add too much nitric to begin with.

I always tried to add as little nitric as needed and if I was not sure I tried to add some more material to see if AR still has power left or it is consumed. It is both HCL and nitric which gets "consumed"?

 

[cejohnsonsr1]

It’s the nitric that gets consumed. You can add a few drops of sulfuric during the dissolving of the gold. It will precipitate lead in the same step. Urea doesn’t denox the solution. But as has been mentioned, if you use incremental additions of nitric there won’t be much excess nitric. Then SMB will consume what little there is before it begins to precipitate the gold.