sulphur (symbol S)
Nonmetallic element in group VI of the periodic table
, known since pre-history (the biblical brimstone
). Essential to animal and plant life, it may occur naturally as a free element or in sulphide minerals such as galena
and iron pyrites, or in sulphate minerals such as gypsum
. The main commercial source is native (free) sulphur, extracted by the Frasch process
. It is used in the vulcanization
of rubber and in the manufacture of drugs, matches, dyes, fungicides, insecticides, and fertilizers. Properties: at.no. 16; r.a.m. 32.064; r.d. 2.07; m.p. 112.8°C (235°F); b.p. 444.7°C (832.5°F). Most common isotope S32
Frasch process (fräsh) [for Herman Frasch, the German-American chemist who devised it], process for the extraction of sulfur from subsurface deposits. Three pipes, one inside another, are sunk to the bottom of the sulfur bed. Water heated under pressure to a temperature well above the melting point of the sulfur is conducted down the outer pipe, and air under pressure down through the innermost pipe. The heated water melts the sulfur and the compressed air forces it through the middle pipe to the surface.
Named after the German-born chemist Herman Frasch, the process was first put to practical use in Louisiana
and made the USA independent of imported sulphur.