Silicon does not exist on its own in nature. Most of it is bound with oxygen
in materials like sand and quartzite and granite rock. The silicon-oxygen bond
in quartz is so stable it can only be broken by white heat!
Silicon producers reduce high-grade quartz sand to elemental silicon via a
carbo-thermic smelting process:
This reaction occurs in an electric furnace at <1,400°C
The carbon monoxide gas (g) leaves the furnace so the silicon cannot react
with the carbon monoxide in a reverse reaction to form silicon dioxide.
The molten elemental silicon, which is about 99 percent pure, is then
cooled and broken into lumps.
When used in silicone production, the silicon is ground into a fine powder
to increase the surface area available for reactions.
Did you know ... most silicon smelting plants run on renewable
hydroelectric power rather than fossil fuels!