Silicon (Si)

Silicon is a metalloid with symbol Si. It was first isolated as a pure element at the beginning of XIV Century, and its name was created from the Latin “silex” (hard stone). Over 90% of the Earth’s crust is composed of silicate minerals, making this metal the second most abundant element in the Earth’s crust (about 28%). It is mostly used commercially without being separated, and often with little processing of the natural minerals. Elemental Silicon also has a large impact on the modern world economy. It is in fact used in the Steel refining, Aluminium casting, solar, electronics and chemical industries. Almost 70% of the world’s Silicon is produced in China. Other large producers are Russia, Norway, Brazil and USA.

PROPERTIES & USE

Aluminium-Silicon alloys (called Silumin Alloys) are heavily used in the Aluminium alloy casting industry, where Si is the most important additive to Aluminium improving its casting properties. Since Aluminium castings are widely used in the automobile industry, this application is thus the largest industrial use (about 55% of the total) of “metallurgical grade” pure Silicon. Its importance in Aluminium casting is given by its significant presence (about 10%) inside Aluminium alloys and its power to improve such properties as hardness, flexibility, thermal resistance, etc.