How can someone separate two elemental solids, in powder form, that are mixed together?

If I have a powder, and its mass is 60% carbon and 40% sulfur, how do I separate one from another in a high school level laboratory?

  • $\begingroup$ If it's mixture of two powders - pure sulfur and carbon then flotation is suitable method. $\endgroup$
    – Mithoron
    Jul 31 '16 at 16:44

Two possibilities:

  1. Distillation: Sulfur has the comparatively low boiling point of 718 K ​(445 °C). Heating in apparatus not affected by sulfur (which leaves out iron) will leave behind the carbon. This is, after all, how sulfur winds up at volcanic vents, where it is harvested. You might even create a retort out of concrete, which would simulate volcanic rock.

  2. Sulfur is somewhat soluble in toluene and in carbon disulfide, but both are toxic and flammable, with $\ce{CS2}$ being particularly easy to ignite. These are not safe to use without proper training and equipment.

  • $\begingroup$ Thank's a lot for taking the time to reply, Dr Pippik. It seems distilation is the way to go. What materials would withstand that kind of temperature though? I assume glass is out of considerantion, and, as you said, iron, because it would react with sulphur. What do you think would be an appropriate material for the apparatus? $\endgroup$ Jul 31 '16 at 4:08
  • $\begingroup$ You might try making a small retort out of Portland cement, sold in most hardware stores. It would probably fall apart after long use, but might suffice for a demonstration (which I suggest you do outdoors, away from flammable objects, and where breezes will remove the fumes). Borosilicate glass or fused quartz could be used, but be sure the opening is wide and/or heated, so it does not get plugged with solid sulfur. $\endgroup$ Jul 31 '16 at 4:13
  • $\begingroup$ Dr. Pippik, the experiment is not to be actually performed, but computionatilly simulated for the Mojang's game Minecraft. I intend to implement chemistry as a mod in that game (a mod is modification added by users for the enjoyment of other users). Thank you for kindly replying once more. I will be looking at borosilicate glass and fused quartz as the theoretical/modeling materials I will use. This is because portland cement is kind of an issue in another question I made (in that question as a starting point for the making of portland cement, I want to be able to prepare CaO). $\endgroup$ Jul 31 '16 at 4:24
  • $\begingroup$ Good luck with the modification! It sounds interesting. $\endgroup$ Jul 31 '16 at 4:29
  • $\begingroup$ That's very encouraging to read, thank you for sharing your knowledge with me doctor. $\endgroup$ Jul 31 '16 at 4:32

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