How much water to add before dropping with smb?

[bhilton]

Hello,

I believe I have seen some discussion on the forum about adding water before dropping with smb - 2 or 3 times the acid volume?

E.g. If I started with 250ML of HCL 61.45% and added 5ML of nitric acid 58%, should I add water to bring the total volume up to 510ML (255ML * 2)?

And I'm also curious, what is the purpose of adding all that water?


Thank you!
Bill

 

[FrugalRefiner]

Goldsilverpro (may he rest in peace) was a refiner for decades and took a very scientific approach. He found through experimentation that diluting to three times the volume was optimal.

The purpose of dilution is that concentrated AR can hold a bit of silver in solution, even though silver chloride is generally considered insoluble. But in a solution with a high chloride content, some of the silver can form a complex and stay in solution. When you dilute the solution, you lower the chloride content, and the silver chloride will precipitate out of solution. Filter till the solution is crystal clear and you should be able to eliminate silver as a contaminant in your gold.

Where do you find HCl that is 61.45%? And if you only need 5ml of nitric, do you really need 250ml of HCl? If your HCl is truly 61.45%, you may need to dilute further.

Dave

 

[Yggdrasil]

Hello,

I believe I have seen some discussion on the forum about adding water before dropping with smb - 2 or 3 times the acid volume?

E.g. If I started with 250ML of HCL 61.45% and added 5ML of nitric acid 58%, should I add water to bring the total volume up to 510ML (255ML * 2)?

And I'm also curious, what is the purpose of adding all that water?


Thank you!
Bill

The purpose is to get out as much Silver Chloride as possible.
If there is no Silver in your feed stock it don't matter.
I have not done this but deals solely in E-waste.

If you put in a few good chunks of ice and filter it while really cold it is no problem.

Are you sure your HCl is not 31.45%

 

[bhilton]

Goldsilverpro (may he rest in peace) was a refiner for decades and took a very scientific approach. He found through experimentation that diluting to three times the volume was optimal.

The purpose of dilution is that concentrated AR can hold a bit of silver in solution, even though silver chloride is generally considered insoluble. But in a solution with a high chloride content, some of the silver can form a complex and stay in solution. When you dilute the solution, you lower the chloride content, and the silver chloride will precipitate out of solution. Filter till the solution is crystal clear and you should be able to eliminate silver as a contaminant in your gold.

Where do you find HCl that is 61.45%? And if you only need 5ml of nitric, do you really need 250ml of HCl? If your HCl is truly 61.45%, you may need to dilute further.

Dave

Sorry Dave, correction, my HCL is 31.45%.

Thank you for help.

And if I don't add water and for my 1st dirty drop I don't care about a small amount of silver content, will the lack of water cause any issues dropping gold with smb?

The reason I did 250ML is because I had burnt up a bunch of napkins, floor sweeps, a little sand paper, etc. and I chose to go directly to AR right in my 8" x 8" Corningware dish. It helped cover the surface area of the bottom of the dish to use 250ML.

 

[Yggdrasil]

Sorry Dave, correction, my HCL is 31.45%.

Thank you for help.

And if I don't add water and for my 1st dirty drop I don't care about a small amount of silver content, will the lack of water cause any issues dropping gold with smb?

The reason I did 250ML is because I had burnt up a bunch of napkins, floor sweeps, a little sand paper, etc. and I chose to go directly to AR right in my 8" x 8" Corningware dish. It helped cover the surface area of the bottom of the dish to use 250ML.

If you don't mind for a bit of Silver contamination, just go straight to SMB after filtering cold.