Melting silver oxide, orange flame?

[Hartbar]

When melting silver oxide in glazed fused silica dish, with a torch, I pour into graphite 2oz molds.
The flame on torch turns orange after first batch, any idea why this happens?

 

[CrystAG]

I would suspect your are burning sodium.

 

[Yggdrasil]

When melting silver oxide in glazed fused silica dish, with a torch, I pour into graphite 2oz molds.
The flame on torch turns orange after first batch, any idea why this happens?

I suspect CrystAG is correct.
How did you get the Silver Oxide?
Conversion with NaOH?
Maybe some of the NaOH is still in there?

 

[Hartbar]

Original material is sterling. I cemented off copper, thorough rinsing with distilled water.
After about 30 rinses, waste water was neutral PH, no copper present when checking with ammonia.
The resulting silver round from ingot is .9999 Silver on sigma machine. Orange flame just confuses me.

 

[Hartbar]

Where did sodium come from?

 

[Yggdrasil]

Original material is sterling. I cemented off copper, thorough rinsing with distilled water.
After about 30 rinses, waste water was neutral PH, no copper present when checking with ammonia.
The resulting silver round from ingot is .9999 Silver on sigma machine. Orange flame just confuses me.

Then it is Silver not Silver Oxide.
Silver Oxide forms when Silver Chloride reacts with NaOH to a black powder, Silver Oxide.

 

[Hartbar]

Any idea on orange flame though?

 

[Yggdrasil]

Any idea on orange flame though?

What kind of gas is it?
Usually a reducing flame is orange and a oxidizing flame is blue.

 

[Hartbar]

I use a hoke torch with propane and oxygen, backed up with two Mapp torches.

 

[Yggdrasil]

I use a hoke torch with propane and oxygen, backed up with two Mapp torches.

And you are not running low on Oxygen?

 

[Hartbar]

And you are not running low on Oxygen?

YES!
Thank you, noticed ox tank was low yesterday.
Appreciate all the input.
What a great forum this is.

 

[sinnegam]

Did you use Borax as flux, or to glaze the crucible? It is sodium tetraborate (sodium, boron and oxygen). If you got some on the torch tip, that may be your culprit.

 

[Hartbar]

I do you use borax to glaze crucibles yes. Is there an alternative?

 

[Hartbar]

I think YGDD nailed it though with low oxygen tank level. I recall issue before with odd flame when tank was low.

 

[orvi]

Did you use Borax as flux, or to glaze the crucible? It is sodium tetraborate (sodium, boron and oxygen). If you got some on the torch tip, that may be your culprit.

Yup. That can be it. And also impurities in gas or oxygen. Or low oxygen - if this is the case, flame will probably soot or refuse to melt the metal - low efficacy of combustion.