Flux Recipe Assistance

[Journey's End]

Hi everyone, new guy here. Can anyone tell me how to determine the best flux recipe based on the results of an XRF scan? Attached are the results from Hazen. Please let me know if I'm doing something wrong or missed something in the So you think your rocks are valuable thread.

 

[goldshark]

Are you trying to smelt the raw rock, or did you concentrate it for the heavies? What kind of rock is it- Carbonate base, porphyry, granite, pegmatite, sedimentary, schist, sandstone, etc. It is a lot easier if you know some basic rock chemistry, rather than trying to decipher an XRF readout. The read out could be for a number of rock types, just easier if you know the minerals in the rock.

 

[Yggdrasil]

Hi everyone, new guy here. Can anyone tell me how to determine the best flux recipe based on the results of an XRF scan? Attached are the results from Hazen. Please let me know if I'm doing something wrong or missed something in the So you think your rocks are valuable thread.

Welcome to us.

 

[Journey's End]

Are you trying to smelt the raw rock, or did you concentrate it for the heavies? What kind of rock is it- Carbonate base, porphyry, granite, pegmatite, sedimentary, schist, sandstone, etc. It is a lot easier if you know some basic rock chemistry, rather than trying to decipher an XRF readout. The read out could be for a number of rock types, just easier if you know the minerals in the rock.

Yes, smelting the raw material. It is all quartz.

 

[Journey's End]

Welcome to us.

Thanks!

 

[Yggdrasil]

Yes, smelting the raw material. It is all quartz.

It is not customary to smelt the whole rock body of ores.
Bad economy in that, if at all possible.
One need to concentrate first.

 

[nickvc]

Unless I’m treading your printout wrong you have very small amounts of values there and the possibility of some fairly toxic elements.
I think you need to crush your ore and produce a concentrate before attempting to smelt it.

 

[goldshark]

Since there are many variations to Silica rocks, you would be better off reading Bugbee's book on assaying, located in the library section of the forum. As Nickvc states, smelting general run of mine ore is not economical. It is better to smelt the concentrates, as smelting is a high unit cost per pound enterprise. It is ok if you are smelting some rocks for an assay. We do repeat- there are potentially some very toxic fumes released during smelting.

 

[Ismael123]

Hi everyone, new guy here. Can anyone tell me how to determine the best flux recipe based on the results of an XRF scan? Attached are the results from Hazen. Please let me know if I'm doing something wrong or missed something in the So you think your rocks are valuable thread.

It's strange , no iron is present?

 

[Journey's End]

It's strange , no iron is present?

Left column, fourth from the bottom. Iron 0.6

 

[Ismael123]

Left column, fourth from the bottom. Iron 0.6

Yes my mistake.
Flux can be determined by acidic or basic nature of ore, that usually people ignore.
A general flux is good to start to find suitable flux.
In your case, low grades of PGE, as everyone mention you, concentration is only mathod that can make it benificialer on some scale. That's another series of test required.
Otherwise it's too low to work. And yes if someone can guide you on direct leach , (if you have matric tons to work in ready stock)

 

[Journey's End]

Thanks everyone. Thus far I've tried 400g each of ore, Chapman flux, and litharge. Unfortunately the bead was less than my scale could measure. This is just a hobby and I would like to learn how to create the flux recipe for any given ore. All the books I have read haven't really explained that part of the process in a way that has made sense to me. Is there no better way than experience / trial & error? I think I have everything else figured out pretty well. If I use lead instead of litharge, do I need to use the same amount? Is there a way to keep the smelt from foaming so much? Would heating more slowly help? How do I determine when the reactions are completed and it's time to pour into the cone?

 

[Yggdrasil]

Thanks everyone. Thus far I've tried 400g each of ore, Chapman flux, and litharge. Unfortunately the bead was less than my scale could measure. This is just a hobby and I would like to learn how to create the flux recipe for any given ore. All the books I have read haven't really explained that part of the process in a way that has made sense to me. I think I have everything else figured out pretty well. If I use lead instead of litharge, do I need to use the same amount? Is there a way to keep the smelt from foaming so much? Would heating more slowly help? How do I determine when the reactions are completed and it's time to pour into the cone?

Read Bugbee, it is well described there.
What kind of Borax do you use?
If you use other than anhydrous it will foam significantly.
The Litharge in addition to a Carbon source will create droplets of Lead all over in the melt so it can grab the values.
Bugbe stresses that the slag/flux have to be thin and watery so the values sink and estimated a time of 1-2 hours before pouring.

 

[nickvc]

I appreciate it’s a hobby but invest in a small crushing unit and a pan , I believe you even get some that run off drills , that will help to produce a concentrate and thus making smelting easier and almost certainly safer.

 

[Ismael123]

Litharge (lead oxide) is a good collecter. As it is finely divided. As heat rises,this act as bombardment of fine sprinkles to collect the metals.

For gold, when litharge convert to metal, it absorb gold,
So chemistry happens inside crucible and you have to understand that.

Here is math, if I am wrong, experts can correct. Litharge(pbo) is actually 92.8 percent of pb.
FFurther you can read
https://goldrefiningforum.com/threads/lead-or-lead-oxide-for-collector-metal.31705/

By the way, you iron in ore can also work as collecter if it's not oxidise to slag.

Edit for some more answers

Foaming is normal in smelt. Try to use flourspar, thinning agent, little hard on crucibles. Check the quantity of litharge. Avoid excess use of litharge than required.

There is no such indication that shows you that melt is complete.
When melt is liquidy, stire to check it if there is anything solid present. Also check on stirer rod tip if melt is liqued or still drops are falling like oil drops. 1 to 2 hours are good time after whole stuff melted.

A good stirring occasionally, is worth

 

[Yggdrasil]

Litharge (lead oxide) is a good collecter. As it is finely divided. As heat rises,this act as bombardment of fine sprinkles to collect the metals.

For gold, when litharge convert to metal, it absorb gold,
So chemistry happens inside crucible and you have to understand that.

Here is math, if I am wrong, experts can correct. Litharge(pbo) is actually 92.8 percent of pb.
FFurther you can read
https://goldrefiningforum.com/threads/lead-or-lead-oxide-for-collector-metal.31705/

By the way, you iron in ore can also work as collecter if it's not oxidise to slag.

I do not think 0.6% Iron is enough for that.

 

[Ismael123]

I do not think 0.6% Iron is enough for that.

Oops. Again my mistake. I thought it's 6 wt%
Thanks for correction

 

[Journey's End]

Read Bugbee, it is well described there.
What kind of Borax do you use?
If you use other than anhydrous it will foam significantly.
The Litharge in addition to a Carbon source will create droplets of Lead all over in the melt so it can grab the values.
Bugbe stresses that the slag/flux have to be thin and watery so the values sink and estimated a time of 1-2 hours before pouring.

For the record, the book you referenced is not easily found in the library section. However I did find a link to it in another thread. Turns out that it is one of the six books I already had downloaded but only read four so far. Reading Bugbee today.
To date, I have only used Chapman flux. So whatever type of borax comes in the premix.

 

[Journey's End]

I appreciate it’s a hobby but invest in a small crushing unit and a pan , I believe you even get some that run off drills , that will help to produce a concentrate and thus making smelting easier and almost certainly safer.

Thank you! I have already crushed to a fine powder. I didn't think I should try heating entire rocks. I will pan some concentrates the next time we get a day above freezing.

 

[Journey's End]

Litharge (lead oxide) is a good collecter. As it is finely divided. As heat rises,this act as bombardment of fine sprinkles to collect the metals.

For gold, when litharge convert to metal, it absorb gold,
So chemistry happens inside crucible and you have to understand that.

Here is math, if I am wrong, experts can correct. Litharge(pbo) is actually 92.8 percent of pb.
FFurther you can read
https://goldrefiningforum.com/threads/lead-or-lead-oxide-for-collector-metal.31705/

By the way, you iron in ore can also work as collecter if it's not oxidise to slag.

Edit for some more answers

Foaming is normal in smelt. Try to use flourspar, thinning agent, little hard on crucibles. Check the quantity of litharge. Avoid excess use of litharge than required.

There is no such indication that shows you that melt is complete.
When melt is liquidy, stire to check it if there is anything solid present. Also check on stirer rod tip if melt is liqued or still drops are falling like oil drops. 1 to 2 hours are good time after whole stuff melted.

A good stirring occasionally, is worth

Thank you! I used a long piece of rebar to stir and poured when it seemed pretty thin but I don't think it was anywhere near an hour after everything melted.