DESCRIPTION
Antimony is a semi-metallic chemical element (Z = 51) located in the group 15 of the periodic table of elements. Its
name and symbol (Sb) derives from the Latin Stibium.
Antimony is not an abundant element in nature and is barely found as a metal in natural state. Antimony appears in two forms: yellow and grey. The yellow form is metastable and is composed by Sb4 molecules; the grey form is metallicand crystallizes in layers forming a rhombohedral structure. It is mainly used in metal alloys and some of its compounds, as the trioxide, to provide fire resistance in tissues, also used in paints, ceramics, enamels, rubber vulcanization, and fireworks.
Antimony is mainly found in nature as Sb2S3 (stibnite, antimonite), the Sb2O3 (valentinite) is a decomposition product of stibnite . Antimony is usually found in the copper, silver and lead ores. Metal antimonides NiSb (breithaupite), NiSbS (ulmanite) and Ag2Sb (dicrasite) are also found in nature.
Antimony is obtained by its direct reduction with iron sulphide, or by roasting of it to Sb2O3 subsequently reduced with carbon. High purity antimony is produced afterwards by electrolytic refining.
PROPERTIES
Elementary Antimony is a crystalline, meltable, breakable, silvered white coloured and with a low electrical and thermal conductivity. It evaporates down to low temperatures. This semi-metallic element resembles a metal in its appearance and physical properties, but it behaves chemically like a non metal. It can also be attacked by oxidizing acids and
halogens.
It reacts violently with strong oxidants (halogens, alkali permanganates and nitrates) causing fire and explosion risks. In acid medium it reacts with nascent hydrogen producing very toxic gas (stibine). Antimony metal is neither classified as hazardous substance by the EU legislation nor as dangerous goods for transport.
APPLICATIONS
- Alloying agent for Lead.
- Friction proof metal.
- Fire retardant agent manufacturing.
- Electrical applications.
