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Hello! I've got my hands on 100 Grams of Bismuth(III)Oxide, and as the topic suggests I want to get rid of the oxygen to get some metal bismuth from it to try and get some crystals.Any suggestions?
The standard way of removing oxygen from bismuth oxide is to smelt it: roast it with coke or charcoal. The reaction isBi2O3 + 3 C --> 2 Bi (liquid) + 3 CO (gas, which escapes)Problem: bismuth vapour is very toxic, as are most of its compounds and their dusts. Carbon monoxide is also very toxic.Bismuth metal melts at around 275°C which is quite a low temperature; lead, for example, melts around 325°C.If you really want to smelt bismuth, then my advice would be not to get iron or lead involved in the system. They will give you huge product separation problems. Keep it simple. But I do not think that the smelting operation is something you should be doing outside a properly equipped lab or foundry.To make large bismuth crystals, the best procedure is to prepare them by slow cooling of the molten metal. Once again I am not recommending that you try this because there will be a significant exposure to extremely poisonous bismuth vapour.An alternative water-chemistry procedure for making bismuth metal crystals would probably involve digesting your bismuth oxide in hydrochloric acid solution to convert the oxide to a soluble chloride, and then find a reducing agent that would very slowly reduce the chloride to the metal. A reduction where the reductant and its oxidation product were both water soluble would be ideal, though the system might be hard to find. It is a very long shot, but if ethanol --> acetic acid or formaldehyde --> carbon dioxide were to work over a period of a week or so, that would be ideal. The usual reductants, particularly zinc or nickel powder reacting with excess hydrochloric acid to produce nascent hydrogen, would not work, because the fast reaction would produce bismuth metal in a very fine sludge which would be near impossible to separate from unreacted zinc or nickel.