Separating Silver Chloride from Alluminium Chloride

[Imran]

Hello,
I have just started with recovering silver and other precious metals from old electronics and I have encountered a problem.
I have some AlCl3 and some AgCl mixed together. Does anybody know how to separate them. Your help will be appreciated.

Ps: I dont speak English very well, so excuse me if there are any mistakes in text above.

 

[Harold_V]

If my understanding of chemistry was as good as your command of the English language, I'd be able to tell you in exact terms what to do. Sadly, that is not the case.

I gather that you have dissolved aluminum, and it is combined with silver chloride?

That being the case, wash the silver chloride with hot water and more HCl. That should keep the aluminum in solution, and allow the silver chloride to settle well. You may find that the solution takes on a color that resembles finely divided silver chloride. In my experiences, that is nothing more than aluminum in solution. It won't settle quickly, but the silver chloride will. When the solids are settled, siphon the solution off, then rinse again with hot water. Repeat this process several times, until the rinse water is relatively clear.

Alternately, you can simply add aluminum in excess, along with some HCl (about 10%), and allow the aluminum to reduce the silver chloride to elemental silver. That requires that you stir the material frequently, so all of the silver chloride will contact the aluminum, which slowly dissolves in the process. When all of the silver chloride has been converted, the solids will be a gray color. Any remaining aluminum will continue to dissolve, and will give off bubbles, making it easy to recover the pieces. Remove them when you consider the silver chloride fully converted.

At that point, rinse the silver with tap water and allow it to settle. Siphon off the solution and repeat several times, until the solution nears being clear of color. At that point you can filter the silver to remove excess water. Attempting to filter before doing several rinses will be a very frustrating experience. The cloudy solution doesn't filter well, if at all.

Harold

 

[Imran]

Thank you very much for your help.

I gather that you have dissolved aluminum, and it is combined with silver chloride? That is correct.

If I use Iron instead of Alluminium,that will also replace silver,wont it?

 

[patnor1011]

Why iron? Aluminum is easy available. Heatsinks in computers, soda and beer cans..................................................

 

[Harold_V]

If I use Iron instead of Alluminium,that will also replace silver,wont it?

Yes, iron (steel) will work equally as well, although I do not speak from experience. I used aluminum because I had it at my disposal (I operated a commercial machine shop). I suggest you avoid using cast iron, which has a large amount of free carbon. Shapes such as angle iron, U channel and other fabrication materials are generally low carbon steel, usually containing no harmful elements, and only a trace of carbon.

Using steel may have an advantage in that it won't yield the same kinds of problems with filtration. Might be a good idea to run a small sample to see how it behaves. The aluminum that is already in solution shouldn't be a problem, although it will be where filtration is concerned. You can avoid that by siphoning, as I suggested before.

Might be a good idea to post your results, so others can benefit. I'd be interested in hearing how it goes, too.

Harold

 

[Imran]

Thank you very much Harold. I will post the results as soon as I try this.

Imran

 

[Imran]

I put steel plate inside glass container, where was AgCl and AlCl3 partly dissolved in water, and silver slowly started to cement. In the evening there was quite a bit of silver on the bottom of glass jar, but I didnt harvested it. I waited until next morning,for the process to finish. In the morning ther was no silver on the bottom of the jar. Does anybody suspect what happened???

 

[Harold_V]

I put steel plate inside glass container, where was AgCl and AlCl3 partly dissolved in water, and silver slowly started to cement. In the evening there was quite a bit of silver on the bottom of glass jar, but I didnt harvested it. I waited until next morning,for the process to finish. In the morning ther was no silver on the bottom of the jar. Does anybody suspect what happened???

It's a little dangerous putting steel in glass containers----for fear of breaking the glass. I suggest you use plastic for such occasions.

What you've described doesn't make a lot of sense. Unless you have free nitric present, and all of the steel is gone, silver should remain. There has to be more going on than you know and/or understand.

Do you have sulfuric acid in solution? Can you provide a picture of what remains? Can you describe the color of the solution, if not?

Harold

 

[Palladium]

It's not making sense to me either.

 

[Imran]

First thank you for your fast reply. The collour of the sollution is yellow.
There is no nitric acid in the sollution(I am 100% sure), but maybe there is a little HCl, and that might be a problem.
As long as I know silver doesnt react with HCl, but then I found this http://www.sciencedirect.com/science/article/pii/S0021979706006710
I dont have nanoparticles, but what else could happened. I cant think of something else.

 

[Imran]

Oh...And there is no H2SO4 in the sollution

 

[Harold_V]

HCl, at worst, converts silver to silver chloride. Unheated, it simply cleans silver. If your solution now contains no solids, it wasn't silver in the beginning.

Harold

 

[chandler_P]

Silver doesn't react with HCl.. HCl would not give up any H+ ions when it encounters Ag.