Sciencemadness Discussion Board

Making ferrosilicon

metalresearcher - 6-12-2015 at 10:19

For iron casting I want to use Ferrosilicon and I made it in small quantities by heating pieces of iron, aluminum and SiO2 sand.

Unfortunately I cannot analyze the result, but it should be 70%Fe and 30%Si.
It is based on the fact that at high temperatures (> 1500 C) Al reacts with SiO2 and makes silicon, which I heated with an electric arc to reach extreme temperatures. I don't know why it is so 'boiling' (3:15). In the result it is to see, beside the chunk of frozen FeSi (5:38) , some dark gray crystals can be seen (silicon ?).

Here a video:

macckone - 7-12-2015 at 05:39

Profesional metalurgist would make the silicon purify it then dissolve it in pure iron under an argon atmosphere. The iron and silicon would be ground for the second reaction.

DeIonizedPlasma - 8-12-2015 at 20:44

I do not know much about alloy making, but is there a reason you did this in one step rather than making silicon and isolating it to the best of your ability, then making the alloy? The sand would seem to add an unnecessary element of possible failure or loss of efficiency.