simple question

[brjook]

can you just melt silver chloride instead of the NAOH and cayro .i tried it a few times and it came out as a black soup and wasn;t sure if i got al the silver metal out of it.

 

[butcher]

Melting silver chloride without converting it to metal first, will burn a lot of the silver off as fumes or create the black soup you are describing.
You probably lost much of your silver and did not get all of it.

 

[MysticColby]

I tried not converting it at first (never will I want to do it again). But you can't just melt it as-is: as butcher said, a lot of it will burn away into the air.
When I melted silver chloride, I mixed it with a lot of sodium carbonate (I believe 1 part silver chloride to 3 parts sodium carbonate is the recommended amount, but don't quote me on that). I could tell some silver chloride still burned away, as evident by the white smoke, and the resulting flux mix was thicker than the silver. Eventually I scooped off the flux and poured the silver like normal.
I do not recommend this, only state it as better-than-without-it.

you should at least react your silver chloride with sodium hydroxide to convert it to silver oxide. silver oxide will convert to silver and oxygen when heated, the oxygen then being released into the air. I would still mix in a small amount of sodium carbonate for the likeliness that not all the silver chloride was converted.

and of course, the best option of all: full conversion to metallic silver before melting

 

[butcher]

Cement your silver from solution when you can using copper metal buss bar, to convert the silver nitrate to cement silver metal powder, which can be washed and directly melted to silver.

Avoid making silver chloride whenever you can.

 

[samuel-a]

can you just melt silver chloride instead of the NAOH and cayro .i tried it a few times and it came out as a black soup and wasn;t sure if i got al the silver metal out of it.

As mentioned above, AgCl will not decompose upon heating but rather get liquid and/or sublime spontaneously (especially if a torch is used).

The process of smelting AgCl with Na2CO3 (soda ash) is well described here in the forum, and here are the highlights:

For every amount of DRY AgCl you would need to add 36.97% soda ash, would be wise to round it up to 40%. For example, for one lb (453.6g) dry AgCl you would need to add 181.44g soda ash.

You can conclude the above numbers from the redox equation, as you can see, the molar ratio is 1:2 (Na3CO3/AgCl):
Na₂CO₃ + 2 AgCl = 2 Ag + CO₂ + 2 NaCl + 1/2 O₂

The two powders should be very well mixed, preferably in a bell mill or a high speed mixer to ensure physical contact of the two ingredients with each other.
This is very important as the reduction itself occur before the melting point of either. Hence the need for evenly mixed powder.

The heating must be done evenly through the crucible to prevent any vaporization, preferably the smelt will be done in a kiln where you can slowly raise temp' at a rate of about 15-20 degree C per minute until you reach 400C.
Keep the temp' at 400-420C for about 10 minutes and then continue to silver melting point.

The resulting slag should be white with some shades of gray (assuming the AgCl was cleaned and washed properly). Any other colors will indicate either having contaminants in your silver or an incomplete reduction.

Warning, while dealing with dry powdered AgCl a respirator is a must.

 

[MysticColby]

lol, that always happened to me in math. right concept, wrong direction. your calculations show 2.5 g AgCl + 1 g Na2CO3 (close to 3:1, whereas I said 1:3)