Platinum, Silver & Iodine recovery

[vikasn]

I need to recover Platinum, Silver& Iodine from a Spent Silver Iodide stream. Platinum content is about 3-4 %. What is the best way

 

[andu]

Iodine should sublimate fairly easily, no idea how your material looks, then platinum and silver tend to stick togheter, i'm clueless however how you should proceed. You should read "the book" regarding the silver/platinum separation, i'd recommend a electrolitic cell however.

 

[Yggdrasil]

Iodine should sublimate fairly easily, no idea how your material looks, then platinum and silver tend to stick togheter, i'm clueless however how you should proceed. You should read "the book" regarding the silver/platinum separation, i'd recommend a electrolitic cell however.

This a strange approach Andu.
First you say you are clueless and then you make recommendations?

 

[andu]

It's about as far as I could get, it's more than nothing but not close to what i believe is needed to know.

 

[samuel-a]

I need to recover Platinum, Silver& Iodine from a Spent Silver Iodide stream. Platinum content is about 3-4 %. What is the best way

Is it in solution?
Iodine/Iodide? Amount?

 

[vikasn]

Solid Siver Iodide. Platinum content is 3-4%. Remaining 95% is Silver Iodide

 

[samuel-a]

Actually, hot AR might do the trick.
Grind the AgI to fine dust and add nitric slowly.
You should end up with AgCl(s) and Pt(aq).

 

[Lou]

I would reduce with hydrogen at low temperature, 350-400 C.

Then I'd collect HI by condensation with cold trap and water.

Then Pt/Ag separate by digesting the silver in dilute nitric acid. Solution should be colorless.

 

[Alondro]

Silver iodide is a tough one. I don't know if it would react with sodium hydroxide. Iodide is a fairly strong reducing agent,

Most processes I see for reducing silver iodide to silver metal and iodine use an electrochemical process of finely powdered silver iodide suspended in a hydrous potassium iodide solution.

 

[Lino1406]

I would reduce with hydrogen at low temperature, 350-400 C.

Then I'd collect HI by condensation with cold trap and water.

Then Pt/Ag separate by digesting the silver in dilute nitric acid. Solution should be colorless.

I assume silver iodide should be in liquid state, or am I wrong?

 

[justinhcase]

Silver iodide? Have you been involved in cloud seeding?
The compound is normally a bright yellow solid, but samples almost always contain impurities of metallic silver that give a gray coloration.
The silver contamination arises because some samples of AgI can be highly photosensitive.
If it is unstable enough for light to denature it should denature by any of the normal denaturing methods.
https://patents.google.com/patent/US2060539A/en

 

[Lou]

Lino, it would be a solid. It can be done a number of ways. In the quartz tube furnace with hydrogen works well.

AgI, AgBr, AgCl...they all do the same and you get metallic silver from HX which you can scrub or reuse in the case of the more useful heavier reducing acids.

 

[Lou]

Wow Justin, that patent is sure a lot of work!

 

[justinhcase]

Wow Justin, that patent is sure a lot of work!

yes, but I thought it was interesting as it allows you to recover the iodine as well.
Could be useful though not terribly valuable.
No point in wasting it if practical.