The history of silicon (Si) began shortly after 1800 when Davy concluded that silica was a compound, not an element. Silicon is second only to oxygen in occurrence in nature. It constitutes 27.6% of the Earth’s crust. Man knows more than 200 different varieties of silicon: quartz, quartzite, chalcedony, rock crystal, opal, sand and many others. Silicon is a strong deoxidizer; this property determines basically its use in metallurgy. Commercially, pure silicon is used for the production of semiconductor, silicon bronzes, etc. It is used as a deoxidizer, in the forms of ferroalloy, in the production of all kind of steels. High amounts of ferrosilicon in the form of powder are used as a slag deoxidizer; it is also used for the reduction of various oxides in ferroalloy production.