AgCl to Ag+AlCl3

[kurtak]

I’ve got about 3300 lbs of AgCl to process

Trust me - with that much AgCl you DO NOT want to use the lye/sugar method !!! (you can ask me why & I will be glad to explain why)

Hands down & without question - with that much AgCl - the BEST method (& answer) is to go back to the iron/acid/cement mixer method (though zinc could be used in place of iron)

You need to tell your boss that - though "on paper" aluminum "should" work - so we have tried that - BUT - we have run into problems with that --- so I went in search of why aluminum is giving us problems

In my search the answer to that problem is ------ (so what Lino said)

Aluminum has a major drawback, producing aluminum oxide which is hard to get rid of

you need to further tell your boss that this advice is coming from some LARGE scale refiners that work with this stuff EVERYDAY

Tell him (your boss) that based on advice from these "actual" refiners - we need to go back to the iron/acid/cement mixer method - as the BEST method for that much AgCl

I believe that Lou (who "runs" 4 "large" scale refineries) will back me up on this

Kurt

 

[kurtak]

I’m getting resistance from the boss

(I only have granulated sugar from the break room because I’ve been told to stop but I’m not giving up on it lol)

my boss is a chemist.

You need to tell him - we have two options - we can continue with a process we "think should" work (aluminum) but isn't working --- or - we can follow the advice of refiners that do this every day for a living

go back to the iron/acid/cement mixer method

Kurt

 

[snail]

Search for posts from goldsilverpro. Unfortunately he has passed away, he posted much info on the sodium hydroxide sugar method.

If you search for posts with silver chloride authored by him you will find the best information.

He used at one point a 50 gal drum with a lightning mixer to convert.

Gives amounts per oz of silver.

 

[Shark]

I have never worked on as large scale as Kurt and many others but after playing around a bit I would never recommend the lye/sugar method. Iron and sulfuric is a very good way to go for many reasons of which much has already been posted. Unless you have very clean silver chloride use the iron/sulfuric you will be save a lot of headaches.

 

[galenrog]

Both methods are great choices for converting silver chloride. Each has advantages and disadvantages. All has been covered on this forum many times.

It is to the benefit of any refiner calling himself a professional to be intimately familiar with both. Doing so allows the best choice for circumstances at hand.

Both methods require experience and expertise.

Forget using aluminum. More trouble than it is worth. For experience, however, perform a few small scale experiments to demonstrate the pitfalls.

Enjoy.

Time for more coffee.

 

[silver1]

I do anywhere from 600-800 lbs per month average ...... all sugar processed.

 

[orvi]

When we are talking about 3000lbs of AgCl, most economical method will certainly be Fe/H2SO4, that is for sure.
I don´t know how and where you obtained so much silver chloride, but if made in your facility, I will seriously think about other methods. AgCl making is nice and easy, but converting it back to silver isn´t that straightforward. Purity required is key to answer here - if you will be happy with 98%, stick copper bar to the filtered AgNO3 solution and agitate. You will obtain nicely settling silver cement, which is easy to filter from the junk.
Sticking a iron bar into the filtered solution will recover the copper.
If you are aiming on higher purity, take this silver and electrorefine it.

Lye/sugar method is also cheap to proceed, but it requires vessel with overhead stirrer, or blender-like vessel to stir and break the precipitate simultaneously. I learned when doing this, there is no need to add every reagent at once. You can do it in controlled way to prevent any runaway.
Conversion of AgCl to silver oxide require some heating, but it can be done in few hours, or even less time, if agitation is strong. Then, you will need thermometer to be present in the mixture and adding the syrup (I use crystal sugar) slowly, and watching the temperature rise. If it climbs too high, stop adding syrup and left it cool down for another addition. When temperature stop rising after addition, reaction is done.
I can imagine this to be scaled up to tens of kilograms at once. With proper equipment, of course.

But all big guys are using Fe/H2SO4 or direct smelting methods.

 

[Shark]

I found the post that made me think the way I do but don’t know how to link it from my phone. I will try again when I get home this evening. I will say galenrog is right about knowing both methods. The way he said it is more along the lines of what I was thinking. Basically if you have a “dirty” silver chloride use the iron/ sulfuric method but if your working with a fairly clean silver chloride use the lye/sugar method.

 

[Alondro]

I’m taking it really slow while adding sugar (I only have granulated sugar from the break room because I’ve been told to stop but I’m not giving up on it lol) and I am starting to see the silver in the bottom. Would you happen to have a good starting ratio so when I try a larger batch next time I’m a little closer to my goal? I’m also using caustic soda because I don’t have any dry lye, will that make any difference?

I actually use a concentrated liquid lye/caustic soda since I warm and mix the silver oxide to make sure all the chloride is converted.

I've made 6 ounces of silver, one ounce at a time, adjusting the method to get the best result.

You can overload it with sugar. Basically, you can't add too much. You just end up wasting sugar once the silver is reduced, that's all.

 

[Alondro]

When we are talking about 3000lbs of AgCl, most economical method will certainly be Fe/H2SO4, that is for sure.
I don´t know how and where you obtained so much silver chloride, but if made in your facility, I will seriously think about other methods. AgCl making is nice and easy, but converting it back to silver isn´t that straightforward. Purity required is key to answer here - if you will be happy with 98%, stick copper bar to the filtered AgNO3 solution and agitate. You will obtain nicely settling silver cement, which is easy to filter from the junk.
Sticking a iron bar into the filtered solution will recover the copper.
If you are aiming on higher purity, take this silver and electrorefine it.

Lye/sugar method is also cheap to proceed, but it requires vessel with overhead stirrer, or blender-like vessel to stir and break the precipitate simultaneously. I learned when doing this, there is no need to add every reagent at once. You can do it in controlled way to prevent any runaway.
Conversion of AgCl to silver oxide require some heating, but it can be done in few hours, or even less time, if agitation is strong. Then, you will need thermometer to be present in the mixture and adding the syrup (I use crystal sugar) slowly, and watching the temperature rise. If it climbs too high, stop adding syrup and left it cool down for another addition. When temperature stop rising after addition, reaction is done.
I can imagine this to be scaled up to tens of kilograms at once. With proper equipment, of course.

But all big guys are using Fe/H2SO4 or direct smelting methods.

I've seen a couple people directly smelt silver chloride. Does that actually work well? I had thought it would melt and some would vaporize before reducing, leading to loss. Does a carbon source need to be added?

 

[Shark]

Anyone remember the old E.F. Hutton commercials? Here is all it took for me to decide to go a certain way....

https://goldrefiningforum.com/threads/converted-silver-chloride.27615/post-291402