Fortunately, the raw Si is abundantly available from steel industry and only a small part of it is required for the semiconductor industry. Since it is a byproduct from steel industry, it is commonly called Metallurgical Grade Silicon (MGS). MGS is poly crystalline material with a purity of about 99%. It is made by the reduction of SiO2 (quartz sand) with carbon (coal) in huge furnaces lined with carbon, with big graphite electrodes inside (carrying huge amounts of current) at about 2000°C. The reaction is
C (s) + SiO2 (s)
Si (l) + CO (g)