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chemical of the month Sulfur
Beiiaire High School Beiiaire, TX 77401
Sulfur, a yellow, hritlle solid in its elemental form, is considered to he one of the five basic raw materials of the chemical industry. 11s old name was "brimstone". Historv Widely distributed over the earth, sulfur was one of the first chemicals found by the caveman; witch doctors burned it to drive away evil spirits; and i t s inflammability symbolized destruction and terror fur the wicked in the Bible. Alchemists, who believed matter could be resolved into three elementary principles-sulfur (heat), salt (solidity), and mercury (lib quidity)-used the name sulfur to designate all combustible substances. By the end of the eighteenth century, Davy described sulfur as a resinous material which contained hydrogen and oxygen as essential ingredients. Gay-Lussac firmly established its elementary nature in 1809.
468
Journal of Chemical Education
The Cuiver Academies Cuiver, Indiana 4651 1
Production Until the beginning of the twentieth century, most of the world's sulfur production came from the shaft mines of Sicily where the brimstone was mined by methods similar to those used in coal mines and then heated in furnaces to separate the sulfur from the rock. The development of the Frasch Process in 1894 greatly increased production. This method consists of forcing superheated water (170°C and 100 lb/in2) into a sulfur deposit to melt the solid. Compressed air mixes with the melted sulfur forming a foam which flows to the surface, where the emulsified sulfur forms a solid of high purity (99.5-99.8% S). Nonelemental sulfur is recovered as SO2 from metal smelting operations and pyrite sources by roasting ores in furnaces.
Alice C. Johnsen
Occurrence Sulfur exists in the earth both as the free element and in a variety of combined forms. It has been identified in moon rocks and in a ring encircling the planet Jupiter. while limited amounts of the elementary form are found in volcanic regions (Japan and Mexico), the most economically important deposits are assuciated with gypsum and limestone sedimentary rock formations (Sicily, Poland, Iraq, Texas, and sulfur include ~ ~ ~ ~i ~ iiwhich ~ contain ~~ ~ ) ~ , ~ ~ sulfides of iron, zinc, lead, and copper, and sulfates of sodium, magnesium, calcium, and harium. A third important source is the oil industry where commercial sulfur is produced by the purifications of "sour" refinery gases.
DARRELL H. BEACH
The intent of this monthly feature is to put more descriptive chemistry back on the scene in our modern chemistry courses. This editor sees this feature as sewing several purposes far the busy chemistry teacher: ( I ) increasing the knowledge of andlor reviewing descriptive chemistry for his or her awn background; (2) assianina written andlor oral student reports on
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Damell H. Beach brings with him to Ue JWRNAL, numerous awards. citation% and 24 years of secondary school teaching. He received his B.A. in Chemistry from Central Michigan University in 1957, his M.A. from the University of Michigan in 1963, and hisEd.0. fromthe University of Sarosota(f0rmeriy LauUniversity) in ,973. Dr. Beach is presently a Master Instructor of Chemistry and the Eugene C. Eppley Chairholder of Chemistry at the Cuiver Academies. He was the 1977 recipient of the Outstanding Chemistry Teacher from the Purdue ACS Section ~ and was the 1979 regional MCA Award winner. He has also been an NSF and GE Fellow. ~ r Beach . has authored three books and has over two dozen other publications. He has served on the ACS-NSTA Level ii Examination Comminee since 1968 and has been chairman of the group since 1974.
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may becomk a eart of thk course syl-
1) Hydrogen
Hz + S
Physical Properties
2) Metals
Fe Fe
A variety of nllofropic states of rlcmrnrary sulfur have h e n identified. %,lid cryst;dline sulfur exists either as rings of 6 12 sulfur atoms (cyclohexasulfur, Ss; cyclooctasulfur. Ca; etc.) or as chains of sulfur atoms (catenasulfur. S,). Cvclooctasulfur. Ss, the most common ring form, has three principal allotropes:
3) Nonmetals
Tons of sulfur are recovered daily a t oil refineries by:
11 Orrhorhmnhe
