Having a melting issue..

[Fettigconstruction1@gmail]

Trying to figure out what happened with this melt. Propane furnace, clay graphite crucible, 2400 deg.F. never had one not pour out. Had almost 1/4 thinner. Why the weird colors. Had 15 Oz of gold silver mix almost clean with maybe an Oz. Of black sands. I am stumped.

 

[Yggdrasil]

Trying to figure out what happened with this melt. Propane furnace, clay graphite crucible, 2400 deg.F. never had one not pour out. Had almost 1/4 thinner. Why the weird colors. Had 15 Oz of gold silver mix almost clean with maybe an Oz. Of black sands. I am stumped.View attachment 64480

How did you get a "clean" Gold Silver mix?
And then you are talking about black sands in the same mix, this needs some more explanation.
What do you mean with 1/4 thinner?
Was the Flux one fourth of thinner (Cryolite or similar?)

 

[Fettigconstruction1@gmail]

How did you get a "clean" Gold Silver mix?
And then you are talking about black sands in the same mix, this needs some more explanation.
What do you mean with 1/4 thinner?
Was the Flux one fourth of thinner (Cryolite or similar?)

I ran it across a gold table several times and it was almost pure gold and silver like I said. Maybe pgms too. And 1/4 of 15 Oz to start so 3 5 Oz of thinner. Used silica sand as an oxidizer.

 

[Yggdrasil]

I ran it across a gold table several times and it was almost pure gold and silver like I said. Maybe pgms too. And 1/4 of 15 Oz to start so 3 5 Oz of thinner. Used silica sand as an oxidizer.

What is your thinner?
How do you make up your flux?

 

[goldshark]

It looks to me like it is a matte (containing some Sulphides ). Sulphides will have a golden metallic luster, resembling Au, even under a microscope, when freshly ground, and concentrated by gravity. Try re smelting using either some nitrates to oxidize it, or simply put some steel nails or rebar in the soup. Remove the iron prior to pouring. Silica is not a great choice for an oxidizer. It is usually used in combination with Soda Ash (basic side of flux ), to keep from prematurely eroding your crucible, leading to a melt through. Are you using a collector metal? More info on ores and fluxes will give better answers.

 

[Fettigconstruction1@gmail]

It looks to me like it is a matte (containing some Sulphides ). Sulphides will have a golden metallic luster, resembling Au, even under a microscope, when freshly ground, and concentrated by gravity. Try re smelting using either some nitrates to oxidize it, or simply put some steel nails or rebar in the soup. Remove the iron prior to pouring. Silica is not a great choice for an oxidizer. It is usually used in combination with Soda Ash (basic side of flux ), to keep from prematurely eroding your crucible, leading to a melt through. Are you using a collector metal? More info on ores and fluxes will give better answers.

I used the black sand flux thinner and

What is your thinner?
How do you make up your flux?

I bought some black sand flux and flourospar. Usually just use equal parts borax to material then a teaspoon or two of flourospar. But this o e was frothing horrible so figured needed an oxidizer so put sand in. It did burn a hole in my crucible. And all the gold and silver pour out in the borax flux. Don't understand why it wasn't in the bottom of the crucible?

 

[Barstool miner]

It looks to me like it is a matte (containing some Sulphides ). Sulphides will have a golden metallic luster, resembling Au, even under a microscope, when freshly ground, and concentrated by gravity. Try re smelting using either some nitrates to oxidize it, or simply put some steel nails or rebar in the soup. Remove the iron prior to pouring. Silica is not a great choice for an oxidizer. It is usually used in combination with Soda Ash (basic side of flux ), to keep from prematurely eroding your crucible, leading to a melt through. Are you using a collector metal? More info on ores and fluxes will give better answers.

I agree with Goldshark, Did you use Pure Silica sand or was it Regular sand?