Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

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recovery of silver from silver chloride solid (3 replies and 1 comment)

c
zwivhuya
6 years ago
zwivhuya 6 years ago

i would like assist on how i can remove silver metal from an ionic insoluble silver chloride.

M
Mike Rockandel
6 years ago
Mike Rockandel 6 years ago
1 like by David

ammonia

M
inOr
6 years ago

Yes, but there are important safety issues that must be addressed when using ammonia to recover silver. At some concentrations of ammonia in water, explosive silver nitride can be formed. Heating the solution can cause it to explode, and even the solution can explode under the right conditions. Solid Ag3N is a very sensitive contact explosive. Therefore, the ammonia solution should under NO circumstances be allowed to dry, even a little of it, eg. on the sides of vessels or anywhere spills have been allowed to dry, can explode. Keep it in solution and recover the silver from there. I don't know how to do this. Perhaps electrowinning would work.

.999
6 years ago
.999 6 years ago
1 like by David

Is it pure AgCl or is it mixed with something else?

Please describe what materials you are working with and how you got from point a to point b so we may give you the best answer to your situation. The more information you provide about a problem the easier it is to help you.

M
inOr
6 years ago
inOr 6 years ago
1 like by David

Cyanide leaching extracts silver from sulfide ores.  I don't know how well it works on silver chloride, though. If it works, then there are several methods for recovering metallic silver from the cyano complex, including cementation with zinc metal.

I'll throw out some other methods for consideration: 1.) Heat your ore with nitric acid to convert it to silver nitrate + HCl.  Evaporate and water and remaining nitric acid plus hydrochloric acid that the reaction produces. Under mild conditions, this reaction would run in reverse, but if the solution is hot enough, any HCl will be evaporated. When dry silver nitrate is heated above its melting point (i.e. >250 degC), it decomposes into silver metal plus oxygen and nitrogen dioxide.  The latter is a toxic gas, so you must do this under conditions where the NO2 is removed - in modest quantities, a fume hood, or outdoors. 2.) There's an interesting video on You Tube showing how to produce metallic silver from AgCl using lye and sugar.  The lye is added to the AgCl while stirring, keeping the mixture under its boiling temperature (Lye liberates a lot of heat when it dissolves; also the reaction may generate heat.)  When no white silver chloride is visible, sugar is added.  The lye converts the AgCl to silver oxide, Ag2O and the sugar then reduces this to pure silver.  The guy showing the video claims that after rinsing away all the soluble products, the silver remaining is 999 fine.  I don't know what his yield is (metal silver recovered vs. silver content of his AgCl) and he adds his reagents without weighing them.  It's literal 'bucket chemistry', but if your system is small-ish it might work for you.  Search online for www.youtube.com/watch?v=mqYVOT-WybE.  Whichever method you choose, and if you need to absolutely minimize costs, you should do some research to find professional appraisals of the various methods.  

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