Telluride ores

[rookieminer]

I've heard that when tellurium is present in the ore it will pull all of the gold into the cupel, Is this true? Does roasting remove the tellurium? And what other metals when present in the ore will cause simillar problems.
I'm just learning about fire assaying, so I hope you will be patient with my lack of knowledge.

Thanks for any replies,

rookieminer

 

[fireguy]

I've heard that when tellurium is present in the ore it will pull all of the gold into the cupel, Is this true? Does roasting remove the tellurium? And what other metals when present in the ore will cause simillar problems.
I'm just learning about fire assaying, so I hope you will be patient with my lack of knowledge.

Thanks for any replies,

rookieminer

Tellurium can cause a small amount of gold volatilization during cupellation. But most often it is cited as the reason for major or total gold loss by scammers. A low temperature roast will drive off the tellurium and remove any potential problems and associated losses.

You can also analyze the ore for tellurium to determine if it is really present.

 

[rookieminer]

What would be a good method for roasting ore samples before an assay? I mean that doesn't require buying an expensive roaster. Action mining sells one for $13,500, that seems a bit pricey for roasting ore samples.

Thanks for any help

rookieminer

 

[rookieminer]

Can you tell me a good method for roasting ore samples prior to a fire assay?
I bought an electric furnace, and I heard that the gas given off from the roasting will quickly ruin the heating elements. So I would like to do it by some other means.

Thanks for any help,

rookieminer

 

[nickmines]

Us rookie miners gotta stick together.

Tellurium is removed through roasting the ore. Sulphides, arsenides, and I think antimonides as well.

This was my introduction to the chemistry side of prospecting and mining (Geology and crystallography helps but not like chemistry!):

http://www.google.com/search?hl=en&clie ... es&spell=1

Then this will bring you up to full basement chemist status

http://www.archive.org/stream/manualdet ... g_djvu.txt
http://www.archive.org/stream/manualblo ... h_djvu.txt
http://www.archive.org/stream/danasmanu ... h_djvu.txt

 

[fireguy]

I have always roasted in an electric furnace without problem.

If you roast in a gas furnace, you will have to have a separate muffle chamber which does not contain the combustion gasses. The combustion of the gas will comsume all the oxygen and will not oxidize and remove the elements you are tryint to get rid of.

 

[goldriver]

Tellerium is extremely toxic and to be avoided at all costs. Look for a "free gold " vein and forget you ever heard of sulphide ores . . they are a real mess. I heard a 10% sulphuric acid leach will remove tellerium ( turns the pregnent liquor purple). I heard of some guys doing a 4 hour salt roast to 800 f . . to clean up concentrates, but on a commercial basis, that would not be feasible with low grade ore. I bleach everything with great success.