How to make an alloy of Bi and Sb under vacuum?

[restrepoarango]

Hi everyone,

How would you suggest to make an alloy of Bismuth and Antimony under vacuum? Would it be appropriate to use a heavy wall Schlenk flask and hard vacuum conditions?

Thank you,
Andres

[Pyrine]

I'm not sure how your set up is, but you would need to heat the antimony up to melting point before adding the bismuth or you'll end up burning it. I'd recommend doing it in either a ceramic or graphite crucible and making the bullion from that.

[John Cuthber]

I'm not sure how your set up is, but you would need to heat the antimony up to melting point before adding the bismuth or you'll end up burning it. I'd recommend doing it in either a ceramic or graphite crucible and making the bullion from that.

Did you read the bit about a vacuum?

 

The first ref. I found says the melting point of BiSb is 475C which is a bit high for glassware to stand.

[Pyrine]

Ceramic crucibles have heat tolerances, as long as he preheats the crucible before adding the antimony to melt he should be fine. We use them to melt platinum in, which has a significantly higher melting point than antimony. If you'd like I can provide several places where you can purchase them from, they'll contain anything up to about platinum, but no higher, past that you must use graphite or a special plaster of Paris investment mix for ultra high temperatures, course with the mix you gotta make your own crucible, but it isn't impossible to do.