Silver from ore

[kjavanb123]

All,

I have a few kg of an ore that I did fire assay and made 1grams from 100grams of the sample. Is there any chemical ways of producing silver from the ore?

Thanks
Kev

 

[martyn111]

The method I am planning to employ is to crush the galena to powder, dissolve in 35% nitric acid, cement with copper and part with an electrolytic cell. If any of the experienced silver refiners can comment on this possible process I would appreciate your thoughts.

 

[Harold_V]

I see you're talking about galena. While I've never attempted what you suggested, I expect that you're going to have more than enough problems with the lead that's present.

It's pretty commonly accepted that you don't recover values from ores using acids. Even if it works, you don't get selective recovery, so you may create huge problems in succeeding steps.

If you're hell bent on trying this process, I suggest you do so with a small amount to make a determination if it works as you hope, and to determine if you create problems you'd prefer not to face.

Harold

 

[martyn111]

Thanks for your wisdom Harold, The intention was, as Hoke and yourself suggest, to sample before trying any large scale work. I thought as kjavanb123 had asked the question I would throw my intention into the forum for further discussion.
My chemistry knowledge isn't fantastic, I only really started to take an interest in it since finding this forum. Maybe one of the chemists on the forum could possibly answer the question of how to remove the PROBABLE contamination of the silver with lead, I have read and understood that lead can be removed from the dissolved gold in AR using sulphuric acid to produce lead sulphide, would this addition of sulphuric acid to silver nitrate have the same effect on the lead in solution?
Or would creating silver chloride from the dissolved galena and processing by Lasersteves method using dilute sulphuric and iron bar be an overall better proposition?

 

[Harold_V]

Heh! You and I are in the same boat where chemistry is concerned. I am unable to answer questions like that, although I do share your interest in learning. Maybe we can corner Lou on this one. He tends to be our resident authority where chemistry is concerned.

Harold

 

[martyn111]

I found this on another thread with regard to refining silver, hopefully this is the answer to removing the lead from the silver nitrate.

Refining silver with chloride can carry lead chloride through the process.

A few drops of sulfuric acid in your silver nitrate should drop the lead to be filtered out.

I'm not doubting you qst42know but, can anyone confirm that this will work effectively in this context?

 

[qst42know]

Hoke mentions it to remove traces of lead from precious metal refining. I have no idea what it would accomplish with mass quantities of lead.

Please disreguard my comment to use sulfuric acid in silver nitrate solutions it is just plain wrong. I did not intend to mislead anyone just made an error.

 

[martyn111]

Thanks for your reply qst42know, I was aware that it was possible with gold and lead in solution, I was erring on the side of caution, wondering if the sulphuric acid would have any effect on the silver in solution in the silver nitrate.
Experimentation appears to be the order of the day then.
I will be carrying out some sampling towards the end of the week when I recieve the galena.
I will of course update the forum with the results that I achieve.
Thanks to all that have contributed so far to this thread.

 

[Shecker]

Just as a thought I would suggest using a 15% solution of Nitric Acid at ambient temperature and pressure over a period of several days. Recover of the silver would be precipitating the silver as silver chloride, washing out any lead chloride with lots of hot water (+180 degrees F), and converting the silver to metal using a clean source of iron.

When iron reacts with silver chloride silver metal is produced with by product ferrous chloride. This is easy to wash out with lots of hot water.

Another approach (and this is an ancient one) is to use salt and strong acetic acid. The reaction produces silver chloride very slowly. The Chinese use to use this by mixing it in jars with hand cobbed silver ore and burying it in the ground for 6 months. It works but it is slow. It also makes lead chloride. Recovery of the silver would be by the above mentioned process.

A third method and one I used for a long time is ferric sulfate and sulfuric acid. This would be 15% ferric sulfate and 5% sulfuric acid. This will generate sulfates of silver and lead. I use to recover the silver on steel wool and would that this would regenerate the solution slightly.

Randy in Gunnison

 

[butcher]

I would study mining galena, and parkes process, sounds like you are in the lead business, and silver is the gravy.