# Separating Silver from Cadmium H2SO4 + nitrate? HCL precip?



## AztekShine (Feb 12, 2012)

1. Will that work effenctly " poormans nitric acid" I believe.
2. Heated sulfuric will desolve Ag. Is this a good option?
3. So Hoke says precipitate with salt or HCL. 

Will Cd stay in solution?

My only other option would be burning/vaporizing off the Cd. I kno bad idea for newb or anybody.
But I kno I can keep temps between 609 and 1763 but if it's mixed together melting off wouldn't work. Unless it could be separated by something . This last paragraph is just crazy talk . I think acid is the way to go. Just which is best?


----------



## butcher (Feb 12, 2012)

Check out the reactivity series of metals, you will learn much if you understand its principles.

sulfuric would only dissolve silver unless it is very concentrated and hot (VERY DANGEROUS), this would not be my recommendation, too much chance of one mistake disabling you, and about only way to get back the silver would be to convert the silver sulfate to silver chloride (here I see a chance for silver losses).

Burning the dangerous metals off, so you protect yourself from the smoke while using the torch, what happens to these metal fumes in the smoke (they do not just disappear; you probably just have spread that cadmium all over yours and your neighbors yards. 


Nitric acid (not poor-mans), will dissolved the silver (I cannot say but probably cadmium, if not we can separate here), with silver and cadmium in solution, cementing on copper would cement silver and not cadmium (higher in reactivity series of metals than copper).

Homemade nitric would need to be distilled if used.
Sulfuric acid used to make homemade nitric can still be in it and make a silver sulfate (not very soluble salt.

editted word to unless for meaning.
editted my word in sentence, edit above.


----------



## AztekShine (Feb 12, 2012)

So their are losses with converting to AgCl in Nitric acid then also. Am I right? 
So that's why cementing to Cu is the best method?

If I was to repeat the H2SO4 extraction/precipatation i could eventually clean it of all Ag. So it doesn't get thrown out with the acid?


----------



## butcher (Feb 12, 2012)

AztekShine, 
Question: So there are losses with converting to AgCl in Nitric acid then also. Am I right? 
So that's why cementing on Cu is the best method?

My answer (best I know), Maybe a tiny loss depending on work habits but not enough to notice any loss normally(the main loses are not in conversion), but in melting and how well you have converted the silver chloride to silver metal before you melt it, is where you burn up your silver.
Cementing you have cemented silver as silver metal it needs no conversion to metal before melting, so almost no losses at all, it is also easier, less waste generated, and better finished results.



Question: If I was to repeat the H2SO4 extraction/precipitation i could eventually clean it of all Ag. So it doesn't get thrown out with the acid?

my best Answer: forget this method note the warnings do not take these warnings lightly (like you seem to have with melting cadmium above), we are giving you good methods to choose from that will actually work better, forget using the H2SO4 to dissolve silver, way too dangerous and not a good method.
Just for discussion the silver dissolved in the concentrated nitric will need to be diluted (another very dangerous process, if water was poured into acid and you were standing doing this, you may end up in the hospital, or blinded for life, even if you had on safety glasses, and most of your skin hanging from your bloody burnt flesh, you would never want to hear the word silver again), think how much will this silver be worth, do this wrong it would not be enough to pay the hospital bill, I am trying to scare you but I am doing it with the truth...
this dilute silver the silver sulfate would not be very soluble so you would need tons of water (generating tons of waste, then you would need to saturate the tons of water with tons of salt, to get silver chloride powder (not very soluble but you would loose some in all of that water, then you would have to convert to silver metal, doable but not as easy as it sounds, then melt and see how much silver you left as chloride and burn up, like I said forget this idea.

Nitric and cementing on copper, simple clean workable method, but notice I did not say safe, there are many dangers here also, your homework and preparation for doing this process will reveal these.


I am sorry if when I write something I sound like I am whipping you with words, that is not my meaning or intention, it is just how I try and explain things to get you to see the danger, or how this and that does or does not work. If I could explain better with soft words I would but I do not know how.

Now get to that homework we want to see them shinny silver bars. (them Aztec shine silver bars).


----------



## AztekShine (Feb 12, 2012)

10-4 good buddy. Can't thank you enough. It's Aztek with a k by the way 8) lol

I respect acids... I was making mercuric chloride one time and dumped HCL in NaCLO instead of dripping it about 16 yrs ago on mercury.....bad day !

Edit: realization of Cl doesn't symbolize sodium hypochlorite


----------



## AztekShine (Feb 16, 2012)

Now I think about it was the other way around ... Desolve mercury In HCL drip NaClO... Sept I didn't drip the first time!


----------

