Problem resolution best method

Hi Everyone,

How I got to this point is not to relevant it was just a mistake.

Where I am at now is I have silver chloride mixed into a gold drop. I can think of 2 ways to resolve the problem myself and wanted to know which was better or if there is a better way I am unaware of.

My first thought is to convert the silver chloride to silver metal using lye and sugar. Then dissolve the silver out from the gold

My 2nd thought would be to dissolve the gold from the mix and then convert the silver.
With this method I am concerned that the silver chloride will just hold the dissolved gold since it is so light and fluffy which I would think has many small pockets to hold the gold.

I am well aware either method will require much rinsing and such I was just shortening to the basic process.

Obviously I am trying to find the best way. I have never been in this situation before and would think someone may have experience with this in the past.

Any thoughts would be appreciated.

Thanx
MrCrusher

A third option would be to dissolve the silver chloride with ammonia or thiosulfate. Decant the solution off the remaining gold, and add HCl to drop clean silver chloride which can be converted by the method of your choice. The gold can then be dissolved and dropped, again by your choice of methods.

Safety Note: If you choose ammonia to dissolve the silver chloride, be sure to reacidify it promptly.

Dave

Dave,

Thank you for the quick response.

I have limited knowledge in these processes. And had thought silver chloride was insoluble.

Please correct me if my understood process below is correct.

First is to rinse my current mix to a PH of 7 to remove all other elements before I start this procedure.
Then add ammonia to dissolve the silver chloride. This is a small amount of material my estimate is 14 grams of silver and 4-5 grams of gold. I would assume to add the ammonia in small amounts until the silver chloride dissolves as to not have an abundance of ammonia left in solution. Should this process be done cold or use some heat? I would think the 140 - 160 deg F would be reasonable. Then decant the dissolved silver and rinse the gold until clean. At this point I can add HCL to the ammonia/silver solution to convert back into silver chloride. Also when re-dissolving the gold If there is any trace amounts of ammonia left will that cause any issues in that process?

My main questions are what kind of reaction can I expect when adding HCL to the ammonia/silver solution. I have never used ammonia in any of my processes before. Also you said Safety Note: If you choose ammonia to dissolve the silver chloride, be sure to reacidify it promptly. What issues would a delay cause?

Thanx
MrCrusher

MrCrusher said:

First is to rinse my current mix to a PH of 7 to remove all other elements before I start this procedure.
Then add ammonia to dissolve the silver chloride. This is a small amount of material my estimate is 14 grams of silver and 4-5 grams of gold. I would assume to add the ammonia in small amounts until the silver chloride dissolves as to not have an abundance of ammonia left in solution. Should this process be done cold or use some heat? I would think the 140 - 160 deg F would be reasonable. Then decant the dissolved silver and rinse the gold until clean. At this point I can add HCL to the ammonia/silver solution to convert back into silver chloride. Also when re-dissolving the gold If there is any trace amounts of ammonia left will that cause any issues in that process?

Click to expand...

You probably won't need to add heat. When you decant the silver bearing solution and rinse the gold, add the rinses to the silver bearing solution. Since it's just gold remaining, traces of ammonia should not cause any problems, but do rinse it well. If you had PGMs in the mix, the ammonia can cause problems because it will form stable complexes with them, complicating recovery.

My main questions are what kind of reaction can I expect when adding HCL to the ammonia/silver solution. I have never used ammonia in any of my processes before.

Click to expand...

You're adding an acid to a base, so expect heat and fizzing. As you said, add the reagents slowly with plenty of stirring to avoid boil overs. Leave plenty of headspace in your reaction vessels.

Also you said Safety Note: If you choose ammonia to dissolve the silver chloride, be sure to reacidify it promptly. What issues would a delay cause?

Click to expand...

It can go boom. :shock: Ammonia and dissolved precious metals like silver and gold can create explosive compounds. Don't allow the ammoniacal solutions to sit around for too long, and NEVER let them dry out.

Thiosulfate accomplishes the same thing, and is generally safer.

Dave

Dave,

Thank you very much. I will give it a go and let you know how it all works out. This is strictly a hobby so it will be a few days or so.

Thanx
MrCrusher