# Help needed in refining silver



## arie_pk (Jan 10, 2009)

Hi to all
I have been following this forum for the last couple of weeks. This has been extremely helpfull and i never saw so much information about the subject concentrated in one place.
Finally i started my first experiment in refining silver. 
I disolved the scrap silver in a solution of 70% nitric acid and equal quantity of water. It disolved fast and the result was a deep blue with a greenish tint liquid (i know for a fact that the silver was was far from pure). After filtering and diluting, I added salt (i saw too late the method of dropping the silver with copper) and the solution turned milky white. Here the problem started. Instead of getting the cottage texture i got an extremely white and extremely FINE result. After waiting for couple of hours to settle i tried to remove the excess liquid - but the white material from the bottom would start to float and go straight trough my filter without hesitation. So i finally managed to get out the top part of the liquid - by pouring it out, then added with water again, and after few hours pouring the water out again and filling again. I did that 3 -4 times without loosing too much of the fine white material. I know the white material is mostly at least silver chloride since it changed color drastically in the light.
Finally I added some Sodium hidroxide and the white milky fine material turned dark black. I am waiting for the last 12 hgours for it to settle - in it barely started to.

What did i do wrong and what do i do to repair?

Thanks to all

Arie


----------



## Juan Manuel Arcos Frank (Jan 10, 2009)

Arie:

Welcome to the Forum!...you have encountered with a big devil....his name is...COLLOIDS...so let us exorcize him.

Colloids never settle down,when you added the salt to the nitrate solution you formed the colloid,probably some organic contamination was present(i.e.,some kind of plastics or gelatine) or very low concentration of silver nitrate.When you added the sodium hydroxide changed the silver chloride colloid into a silver oxide colloid...so it will never settle down.To settle down the black colloid you have three options:

FIRST,heat the solution to boiling for a few minutes....then let settle down.

SECOND,add hydrochloric acid,stirr well and let settle down.

THREE,add nitric acid again,it will dissolve the silver oxide and it will convert it into silver nitrate then repeat the process adding common salt.

Keep me informed about your progress.

Have a nice day

Manuel


----------



## arie_pk (Jan 10, 2009)

Thanx Manuel. Yes the silver was contaminated probably with some plastic material. I started heating it now and will let you know the results.
Thank you again

Arie


----------



## arie_pk (Jan 10, 2009)

Well Manuel it seems you hit the nail on the head. I boiled the solution for about half an hour and let it cool. After 1 hour i checked it, and it did drop nicely. The solution is still dark somewhat, so i guess by morning i will have more silver on the bottom.

Thank you again 

Arie


----------



## arthur kierski (Jan 10, 2009)

in clearing arie-pic doubts you i am sure helped a lot of members of this forum---thanks manuel


----------



## arie_pk (Jan 11, 2009)

Ok to continue the subject - i did get about 2oz of cement - but the color is coal black instead of the grey i saw on the forum videos (after drying). Does it mean it is very unpure?

Thanx


----------



## Juan Manuel Arcos Frank (Jan 11, 2009)

Arthur:

That is what friends are for.It is my pleasure.

Best Regards

Manuel


----------



## Juan Manuel Arcos Frank (Jan 11, 2009)

Arie:

Let us go through the process:

You dissolved silver scrap in nitric acid forming soluble silver nitrate,added common salt to form silver chloride then added sodium hydroxide to form black silver oxide...you have already solved the colloid problem but the refining process is not finished...you have to reduce the silver oxide to get pure silver.So it is normal that you have got the black precipitate of pure silver oxide.

Looking at Steve´s wonderful videos you will reduce the silver oxide to pure silver using Karo syrup.

Regards.

Manuel


----------



## arie_pk (Jan 11, 2009)

Sorry to be so thick, but this is so new for me. In the video that I saw, silver chloride was converted to pure silver by using lye pellets and syrop. I have silver oxide (not silver chloride) so you mean I have to repeat that process on my silver oxide and will get pure silver? If so - is it ok to use sugar saturated water, instead of kar syrop?


----------



## g_axelsson (Jan 11, 2009)

The lye (NaOH) is converting the silver chloride to oxide, the karo syrup (dextrose) turns the oxide into metallic silver. You have already done the first step in this process so the only step left should be to add the syrup.

I did a search and found this : http://goldrefiningforum.com/phpBB3/viewtopic.php?t=120&highlight=silver+oxide+syrup

Steve is doing it in one step in his video and calls the syrup for deflocking agent. But if you read the comments in the above thread it should be clear that it can be done in two steps and that the dextrose is doing the conversion from oxide. Somewhere I read about doing it in two steps and cleaning the oxide between adding lye and syrup.
In that experiment Steve misplaced close to a third of the silver as unconverted silver chloride, it ended up in his melting dish in the flux.

/Goran


----------



## Juan Manuel Arcos Frank (Jan 18, 2009)

Arie:

I will share with you a secret...you can use common sugar instead of Karo syrup.

To your silver oxide black mud add some sodium hydroxide dissolved in water...stirr well and continue stirring hard and add slowly the sugar(the same grams of silver you have)...keep stirring hard and you will see that the solution starts to boiling forming a grey/green precipitate wich is pure silver.Let decant,pour off the liquid,add a little bit of hydrocloric acid (to break the colloid),stirr,pour off the liquid,wash the mud,,dry and melt.

CAUTION If you use more sugar than needed the reaction will proceed very violent and the solution will blow up...exactly like a volcano..so do it in a large container to avoid this risk.

Have a nice day.

Manuel


----------

