Silicon / Silicon Carbide
Silicon is a semiconductor and as such an important component of solar cells, sensors and integrated circuits. In addition, it forms the basis for a variety of silicate minerals such as those that make up about 90% of the earth's crust. In the form of SiC, it is popular for use as plain bearings and in the refractory industry.
Element | Product name | Grain sizes | Purity [%] | Apparent density [g/cm3] | Grain form/Manufacturing process | Additional information | |
Silicon (Si) | FAST-Si-100 | d(90): d(50): d(10): | 9.5 µm 4.5 µm 1.2 µm | >99.995 | - | - | |
Silicon Carbide (SiC) | FAST-SiC-100 | ds-3: ds-50: ds-94: | 14.2 μm 6.1 μm 1.9 μm | green SiC | - | - | |
Additional specifications upon request
Silicon is a blue-grey, lustrous metalloid in the 14th group of the periodic table. In combination with oxygen, it forms silicate-tetraeder, which can be assembled in several ways thereby giving rise to a vast range of silicate minerals. In fact, the earth’s crust is built up by approximately 90% of silicate minerals, like feldspar to name the most frequent (50-60 vol.%), but also gemstones like aquamarine and emerald.
In German literature, quartz (SiO2) is not considered a silicate, but an oxide mineral. Nevertheless, quartz in the form of sand and quartzite is the main source for pure silicon in the world.
The applications for silicon are widespread and mostly dependant on its purity. The major part of silicon is used in its unprocessed form, as clays or silica sand for structural compounds or for the production of cement. In the form of ferrosilicon, it is added to molten cast iron, where the silicon allows control over the dissolved carbon content in steel. “Metallurgical grade” silicon (90-95% purity) is mostly used for aluminium-silicon alloys (silumin alloys) for aluminium casting in the automotive industry, where it reduces thermal contraction during solidification and greatly improves hardness and wear-resistance.
Silicon is also a semiconductor. Its conductivity is increased by doping with elements like boron or arsenic. This makes it a widely used element for integrated circuits, sensors and solar cells.
For the solar industry, metallurgical grade silicon is purified to >99.99 %, while for other semiconductor applications silicon with a purity of 99.999 999 9 % (9N) is demanded.
Finally, silicon in is the namesake for the Californian high technology region “Silicon Valley”.
The Acheson process is used to produce α-silicon carbide from silica sand (SiO2) and petroleum coke. High-purity β-SiC powders are produced from chlorine-containing carbosilanes using chemical vapor deposition (CVD). SiC is the most common non-oxide ceramic. Components made of SiC have good mechanical properties, exceptional hardness coupled with very good thermal shock resistance and are chemically inert to acids as well as bases. This makes them suitable for use under the most aggressive conditions. SiC is often used in the refractory industry as construction material and heating elements. Another common application are bearings made of SiC.