There is a process named solar furnace pyrolysis which is used to reduce the oxides of various elements by concentrating solar energy. Oxygen is liberated but an oxide slag is left.

$$\ce{SiO2 ->[pyrolysis] SiO + 1/2O2}$$

How can the element can be extracted from the oxide produced?

I am making a project for NASA on space settlements in solar furnace pyrolysis. Can solar furnace pyrolysis be used for obtaining both metals as well as oxygen from the metal containing oxides left after pyrolysis? Can it be done by electrolysis? If possible, please provide with a link with your answer.


1 Answer 1


The answer appears to be forthcoming in the wikipedia article on silicon monoxide and references therein — to quote:

$\ce{(SiO)_{n}}$ irreversibly disproportionates into $\ce{SiO2}$ and $\ce{Si}$ in a few hours between 400 and 800 °C and very rapidly between 1000 and 1440 °C, although the reaction does not go to completion.

The article implies that $\ce{(SiO)_{n}}$ generates a passivating layer of $\ce{SiO2}$ in contact with dioxygen, so presumably the slag would be encapsulated in a thin layer of that.

Additionally, silicon is not generally considered to be a metal, but rather a semimetal or metalloid.

  • $\begingroup$ what about other metals that may be used in this process Mr. richard? can metal semi oxides be electrolysed the same way as metal oxides? $\endgroup$ Mar 2, 2013 at 8:37
  • $\begingroup$ Housecroft and Sharpe, p. 339 indicates that Si is commonly prepared from SiO2 by smelting with a reducing agent (either carbon or calcium carbide). This is in common with the smelting of metal oxides. Purification of the silicon for use in semiconductor devices would require zone remelting, Czochralski pulling or the like. $\endgroup$ Mar 2, 2013 at 9:04

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