Thanks a ton!
Silver chloride conversion issues
- Thread starter icejj
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Thank you for your help. I'm not sure if I'm understanding everything correctly though, did you mean nitric when you mentioned nitrogen?? What is the "vinaigrette"?
No, this is the metallic silver that was poured out of the crucible into cold water, this is the melted silver that was in the crucible that contained both melted silver and the unmelted crumbled pieces. The crumbled pieces (which contain small pieces of melted silver buttons) was taken out of the crucible and placed on the left of the graphite mold in the corningware, while the melted silver was poured into cold water. To add clarity, the pictures do not contain any silver chloride prior to the lye/sugar conversion, everything in the pics is after the lye/sugar conversion. I probably should have stated this beforehand.
I think the Nitrogen is a typo.
Vinaigrette is Vinegar in French and since it is within hyphens I assume it is used in a transfered meaning.
Just as I thought.
And this seems to give a stronger indication that the conversion was incomplete.
I guess you cleaned the AgCl thorughly before adding the Lye?
Can you share how you did it?
Approximately amounts and so on?
in this case, the vinaigrette is in a figurative sense
original name means :
Vinegret (Russian: винегрет[1]) or Russian vinaigrette is a salad in Russian cuisine which is also popular in other post-Soviet states. This type of food includes diced cooked vegetables (red beets, potatoes, carrots), chopped onions, as well as sauerkraut and/or brined pickles.[2][3][4][5] Other ingredients, such as green peas or beans, are sometimes also added
You also have a salad of chlorides, oxides, metallic silver..
nitrogen - nitric acid
I performed several water rinses on the silver chloride until the rinse water was clear.
Then it would be safe to assume that it is mostly AgCl.
What was the origin of the AgCl?
Also worth noting. If you think you have contaminated chloride. AgCI2 is sensitivetp UV light. You can test it to visually see if it turns to an oxide.
Once’s the silver is converted to elemental silver (Ag+).
This will be light grey/light brownish in color depending on how much sugar you add.
Light Grey = 99.9%
Dark Grey = Other base metals 95%+
Less sugar = light grey in color and easier to wash. I usually just add handfuls at a time in large batches.
If you see the photo below. I created molasses with the silver oxide. That’s why it’s brown.
The lye/sugar solution can be neutralized with baking soda. Then simply discarded safely. If you don’t wash the additional sugar and lye it will also cause slag. Just wash the oxide powder and test with ph strip till it’s neutral. Then smelt away!
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kurtak
Well-known member
He answered that here ------
Note; - the following is being post to help icejj figure out his problem - as well as help other members - & is not directed to anyone in particular
Gold filled can be over almost any metal including over sterling silver & in fact gold filled over sterling is quite common
So after the nitric digestion (leach) the nitric should always be checked/tested for silver - which icejj did by adding salt to the nitrate solution to see if a chloride formed
However I would have tested the nitrate solution for silver different then testing with salt (or HCl) and here is why
As I said - gold filled can be over almost any other metal - & that includes lead - though it (gold filled) is rarely if ever put "directly" over lead
Rather - the lead will be used to give weight to a gold filled object - such as a pendent hung on a chain (necklace) & the lead will be used as a core/filler of the object with the shell of the object being made of a "thin" base metal (SS or copper/brass) which then has the gold filled over that thin base metal shell - &/or gold filled object are often made with tin/lead solders - this (lead) is not uncommon with gold filled
Lead dissolves in nitric - therefore it is entirely possible to end up with lead dissolved in your nitric when doing a batch of gold filled & salt or HCl will precipitate lead chloride - which looks just like silver chloride
But - lead chloride does not convert to actual lead with lye/sugar - like silver (chloride) does - so if you have both lead & silver in solution - the salt/HCl will precipitate both as chlorides - but only the silver will convert with the lye/sugar
Therefore - when processing gold filled - you are better served to test (& recover) any dissolved silver in the nitrate with copper which will cement out the silver & will leave the dissolved lead in the nitrate solution
Though (at this time) I don't know for sure - I "suspect" that icejj is likely dealing with both lead & silver chloride
Ways of testing for lead (which should always be done when processing gold filled) -----------
1) you can first test the solution to see if lead is dissolved by taking a small sample of the solution (a few ml) put it in a 50 ml beaker & add "a bit" of sulfuric acid - the sulfuric acid will precipitate lead sulfate - give it a bit of time for the lead sulfate to settle as if it is a small amount of lead you may not see the sulfate if you don't give it some time to settle
2) if you don't do the above test (to first test for lead) but instead go direct to precipitate with salt/HCl you can then test to see if what precipitated is - lead chloride - or silver chloride - or a combination of the two - by exposing the precipitated chloride to light (exposure to direct sun light is best)
Silver chloride - when exposed to light does what it called "photo greying" which causes the white silver chloride to darken (or grey)
How much &/or how fast it "greys" depends on the light it is exposed to - under artificial lighting (normal lighting in a room) it will take a fair amount of time before it starts to "grey" whereas with direct sun light it will happen "almost" instantly --- which is why I recommend exposing the chloride to direct sun light
How it greys - at first it will shift from white to brown or brownish grey - then to a more bluish grey - then a darker purple grey & finally to a black/grey & or even black
ALL silver compounds photo grey which is why it works for developing black & white photos (usually as silver sulfates) but even silver nitrate will photo grey - if you put a drop of silver nitrate on a paper towel & set it out in the sun it will go though the above color changes of the above photo greying process --- in direct sun light it will go from brown to black fairly quick under artificial light it may not go past brown &/or bluish grey
All that said - on the other hand - lead chloride does NOT photo grey - it remains white even if exposed to direct sun light
So exposure to sun light is the test to determine if salt/HCl has precipitated silver chloride - or lead chloride - or combination of silver/lead chloride
If you precipitated both silver & lead chloride the silver chloride will photo grey but the lead chloride will not - so you will end up with "white spots" mixed in the silver chloride that has photo greys - the white lead chloride spots will not go away no matter how long you leave it exposed to the sun
How to get rid of the lead chloride if you precipitated both silver & lead chloride with salt/HCl
Silver chloride does not dissolve in water - not even HOT water
Lead chloride does NOT dissolve well in cold water - BUT - it dissolves very well in HOT water - so if you dissolve the lead chloride with HOT water & then let that water cool back down - the lead chloride will precipitate back out of the water
So - if the photo grey test shows white spots of lead chloride mixed in with silver chloride you need to wash it (the chlorides) with HOT water (boiling hot preferred - you don't need to boil the chloride - just boil the water & then us it for washing)
You can test for when all of the lead chloride is washed out by simply letting the wash water cool back down - you know the lead chloride is washed out when no white cloud of lead chloride forms after cooling down
You can speed up the cooling down test by taking a small sample of the wash water (50 ml beaker or test tube) & putting it in a bowel of ice water - rather then waiting for a large volume of wash water to cool down
For what it is worth
Kurt
