# i evaporated the nitric then added water,does it look right



## goldpete (Jul 7, 2012)

i have made sure i evaporated all the nitric , i had a dark yellowish syrup , then i added 3 times its volume in hot water.
now its a murky greenish colour as you can see in the pic . does this look normal ?


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## Geo (Jul 7, 2012)

for a dirty solution, its looks about right.test with stannous chloride. does it have any solid metal left in solution? filter it good when it cools. add a small pinch of dry SMB and watch for a reaction. did it fizz like crazy or did it just sputter a little? an energetic reaction means it still has free nitric, a small weak reaction means theres still some but should pose little problems when precipitating. dilute the solution with double the volume of water and let it set undisturbed for a couple of hours. any last bit of silver chloride or lead chloride will precipitate out as a white powder. after waiting, filter again and test with stannous.

you should be ready to precipitate.


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## goldpete (Jul 7, 2012)

Geo said:


> for a dirty solution, its looks about right.test with stannous chloride. does it have any solid metal left in solution? filter it good when it cools. add a small pinch of dry SMB and watch for a reaction. did it fizz like crazy or did it just sputter a little? an energetic reaction means it still has free nitric, a small weak reaction means theres still some but should pose little problems when precipitating. dilute the solution with double the volume of water and let it set undisturbed for a couple of hours. any last bit of silver chloride or lead chloride will precipitate out as a white powder. after waiting, filter again and test with stannous.
> 
> you should be ready to precipitate.


no there was no waste material in the mix , originally it was just clear yellow.
and no there was no reaction when i added the water apart from it changing from a yellow syrup to this green colour.


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## Geo (Jul 7, 2012)

goldpete said:


> Geo said:
> 
> 
> > for a dirty solution, its looks about right.test with stannous chloride. does it have any solid metal left in solution? filter it good when it cools. add a small pinch of dry SMB and watch for a reaction. did it fizz like crazy or did it just sputter a little? an energetic reaction means it still has free nitric, a small weak reaction means theres still some but should pose little problems when precipitating. dilute the solution with double the volume of water and let it set undisturbed for a couple of hours. any last bit of silver chloride or lead chloride will precipitate out as a white powder. after waiting, filter again and test with stannous.
> ...



not water. i was talking about adding a pinch of sodium metabisulfite (SMB) and watching for a reaction. read my reply again.


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## goldpete (Jul 9, 2012)

Geo said:


> goldpete said:
> 
> 
> > Geo said:
> ...



yep sry i misread . i have already put 3 times the volume of water before i took the pic . now it has had a couple of days to settle , i see sediment that looks like silver despite being filtered , so tomorrow ill filter again before i try adding smb.
i dont understand why its that colour tho , shoudnt it be gold in colour ? . it was before when i was evaporating


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## Geo (Jul 9, 2012)

concentrated solutions behave differently than diluted solutions. a concentrated solution can hold a small amount of impurities better than a diluted solution. AR when hot, can hold quite a bit of silver chloride. but when it cools and you dilute it, the silver will precipitate out. other impurities will show up as well. i cant tell you the exact chemistry for this, i can only tell you that it does it. maybe someone with more chemistry knowledge can explain it better than me.


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## butcher (Jul 12, 2012)

The yellow liquid turning green when diluted with water make's me think that iron is in solution, iron can also look like dissolved gold.

What materials did you process and how, does the stannous chloride test show gold in solution?


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## gold4mike (Jul 12, 2012)

Goldpete says he's sure he killed the nitric since he evaporated to a syrup, then added water to dilute. 

Please correct me if I'm wrong but, once you have it to the syrup consistency, you must add HCl to expel the nitric.

Simply evaporating off the water and then adding it right back in again will not eliminate the nitric. You have recreated the same problem.


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## butcher (Jul 13, 2012)

True if all of the nitric was not removed adding back water would just dilute the remaining nitric in solution, and remember the same thing happens when you add too much HCl to solution during the evaporation process, as the HCl is about 70% water, this is why we try to evaporate down as far as possible without creating a crust salt, and only add a small portion of HCl and repeat the evaporation for three times total, to be able to expel all free nitric acid from solution and keep the gold dissolved as gold chloride in solution, as we do not wish to burn the gold solution to salt (in the evaporation process which could also result in a portion of our gold volatizing off in the fumes, or reduce it to metal) , and also we do not wish to dilute the remaining nitric in solution to have to evaporate off a bunch of water again before eliminating the nitric, when we evaporate mostly water comes off first, then mostly nitric then HCl, so adding too much water (or HCl) in the process just means more evaporation to remove those stubborn traces of Nitric in solution, wasting time and acids.

Also I am of the belief that when base metals like copper are in solution they may form nitrate salts in the evaporation process, these copper nitrate salts re-dissolve with the addition of a small amount of HCl addition making back aqua regia in solution, so evaporating again expels a portion of the nitric in proceeding with the evaporation process, if this does happen as I suspect it would, then a dirty gold solution would be harder to remove free nitric from than a solution of pure gold.


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## goldpete (Jul 13, 2012)

gold4mike said:


> Goldpete says he's sure he killed the nitric since he evaporated to a syrup, then added water to dilute.
> 
> Please correct me if I'm wrong but, once you have it to the syrup consistency, you must add HCl to expel the nitric.
> 
> Simply evaporating off the water and then adding it right back in again will not eliminate the nitric. You have recreated the same problem.



yeah but after i had evaporated the nitric i did then add hcl , i then evaporated that down and then added more hcl , it was when that was evaporated that i added hot water


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## jeneje (Jul 13, 2012)

goldpete said:


> gold4mike said:
> 
> 
> > Goldpete says he's sure he killed the nitric since he evaporated to a syrup, then added water to dilute.
> ...


goldpete, at this point i think you would be better served to cement out with copper bus bar and start over using CM hoke process found on page 43 thur 48 it will tell you the proper proess using AR from start to finish. Just a though here.
Ken


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