Some problems in my first experience ( Dissolve silver in nitric acid )

xelexo
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Topher_osAUrus said:
Sounds like you should have let it settle and siphoned off the clear solution, only filtering the last bit.
Sometimes thats just the best way to go about it.
Click to expand...
In first experience I don't wash good and don't screen and also I add filter papers and napkins!!!
So I have much residue. I don't Know what are in residue really but I hope They are not silver oxide :?

As palladium said I must don't digest all of my powder so in this way I have considerable residue too. Yesterday I searched in forum and found that decanting is best way but after decanting I must filter to catch any silver powders
A coffee filter can catch all of powders ? like whatman size 4
Buying a coffee filter is easier and cheaper
 
After filtering silver nitrate solution several times with filter paper sheet and coffee filter I see some residue in solution!!!
What's wrong ? I am really confuse and don't want loss my silver.
What are these residue that excess nitric acid can't dissolve them?

My silver nitrate solution is brown and residue is bright brown
http://uupload.ir/files/ijko_vjjmmbkkh.jpg
 
Tap water in the mid east can have 250mg of chloride salts per liter. What converts to silver chloride. To check, just collect some precipitate and add concentrated caustic. If you get nice black, it is silver.
 
Thanks Lino
I add caustic and they convert to black powder immediately. In some steps I used water from well ( My workshop is in the park ) and I thought because it doesn't have Chlorine it is OK I forget it may contain salt. It was my mistake.

Palladium said:
After you wash the batteries in a 5 gallon container with hot water pour the wash water with the powder through a screen to catch any metal fragments.
Click to expand...

Hi Palladium
Do I must wash batteries with distilled water? Can I use tap water in this step? It is very cheaper
Thanks
 
I did what Palladium said but after one day some of gray cements turn to brown :shock:
Is it normal?
I had excess nitric acid but I don't think I did another mistake

http://uupload.ir/files/028k_img_20170923_182554.jpg

http://uupload.ir/files/ajxg_img_20170923_212956.jpg
 
That doesn't look like silver cement to me. How did you cement it? On copper?

I think a lot of your problems comes from the fact that you have zero experience working with silver. Starting with button cell batteries only adds a lot of unknown variables into the mix.

To be frank, you have worked on this project for at least four months now and anyone the least experienced in silver chemistry would know that taking some of your "silver cement", add it in a test tube and a few ml of nitric acid would dissolve it if it was indeed silver cement. Add some HCl or table salt and it would form silver chloride. That test would take less time than it takes for me to write this post.

I suggest that you buy some sterling silver scrap or some scrap silver coins and learn the different reactions of silver. Do the tests that Hoke recommends for silver. You should also test three different methods to recover your silver. Sugar + lye, sulfuric + iron and cementing. This is something you can do in less than a day and it will show you how silver reacts.

Here are the Hoke acquaintance experiments.
http://goldrefiningwiki.com/mediawiki/index.php/Hoke_acquaintance_experiments

Göran
 
@g_axelsson

Thanks but I just dissolve powders after washing and added a copper bar to it in first hour cement was gray but after one day it turns to brown (not all of them) :(
Why add nitric acid to it when I had a transparent solution before cementing ?
And now I have silver cement without solution. Why add hcl to it? (I don't have silver nitrate)

I really don't have time to learning more. I must melt my silver this week and start my business and earn some money! :oops:
 
saadat68 said:
@g_axelsson

Thanks but I just dissolve powders after washing and added a copper bar to it in first hour cement was gray but after one day it turns to brown (not all of them) :(
I really don't have time to learning more. I must melt my silver this week and start my business and earn some money! :oops:
Click to expand...

If you don't have time to learn, you don't have time for business.
At least a successful business.
 
jimdoc said:
saadat68 said:
@g_axelsson

Thanks but I just dissolve powders after washing and added a copper bar to it in first hour cement was gray but after one day it turns to brown (not all of them) :(
I really don't have time to learning more. I must melt my silver this week and start my business and earn some money! :oops:
Click to expand...

If you don't have time to learn, you don't have time for business.
At least a successful business.
Click to expand...
Yes but in future
Now I must earn money because I rent my workshop and remains 5 month of my contract
 
3 months ago I tried to digest some powders with sulfuric acid and H2O2 but after I got silvers again with cementation and add cements to my batteries powders
Is that problem ?

Can I wash it with hcl after drying ?
 
All i can think of is you diluted your solution during cementation and iron precipitated out. Theirs really nothing else in there that could cause brown! Zinc is below copper and will stay in the solution and the hydroxides, if any were left from your water wash would have been killed off by the acid.
 
Thank you
Fortunately brown sludge gone easily with HCl
This is my silver cement. :)

http://uupload.ir/files/c95g_img_20170924_213231.jpg
--------------
I think I added a little water and also added some silver nitrate solution again
But why?
Water raise PH of solution and precipitate iron hydroxide. Right ?
 
Pretty dark for cemented silver.
Maybe some silver chloride has contaminated it and darkened by sunlight.

Id melt with a little bit of soda ash. Just in case
 
Topher_osAUrus said:
Pretty dark for cemented silver.
Maybe some silver chloride has contaminated it and darkened by sunlight.

Id melt with a little bit of soda ash. Just in case
Click to expand...
It was wet and fresh and in my workshop
I thought it is black because it is wet. Today I wash again with a little HCl and tap water. It is a little brighter but not same cements in youtube videos.
Maybe it is better to dissolve again in nitric acid

2 image from wet cement after washing today:
In sunlight:
http://uupload.ir/files/dico_img_20170925_144632.jpg

In workshop:
http://uupload.ir/files/6li7_img_20170925_144729_1.jpg
 
Why HCl? Finely divivded silver cement plus HCl = AgCl.
It should only be in small quantities, unless you heated it or had oxidizer in it. But still, just seems counter intuitive to progress
 
Because I had iron in my solution
http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=50&t=25632#p277475
 
Iron and silver are immiscible.
You could have rinsed very well in hot water and tried to effect separation. Then just dried it and melted whatever didnt get washed away. Iron does not alloy with silver.
Or, you could have used dilute sulfuric, which would have dissolved the iron and left the silver alone.
 
OK
Thanks Topher
I ruined my second experience too :(
It is embarrassing

Today I tried to dissolve them with nitric acid. Most of them didn't dissolve. Residue is purple now and sounds like I make silver chloride. :?
But why purple ? Yes I know UV changes color to purple and I have fluorescent lamps in my lab but I didn't see any white powder. They were black after adding HCl and they were purple after digest in nitric acid
Tomorrow I will try to convert silver chlorides to silver with sugar
 

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