It is of prime importance to every sector of the world's industrial and fertilizer complexes. Sulfuric acid consumption has been regarded as one of the best indexes of a nation's industrial development.
Sulfur is one of the few elements that occurs in the native, or elemental, state.
It also occurs combined with iron and base metals and sulfide minerals and with the alkali metals and alkali earths as sulfate minerals. In petroleum, sulfur is found in a variety of complex organic compounds and in natural gas as hydrogen sulfide. Commercial production of sulfur in the United States is accomplished by a variety of methods dictated by the source of the sulfur. The primary source of elemental sulfur is classified as recovered sulfur. It is recovered during the refining of crude oil and the purification of natural gas.