“Sulfur” has superseded “sulphur” as the accepted spelling (also sulfate, sulphite sulfide etc.) patent searchers will have to take account of both.
Elemental sulfur is extracted by the Frasch process: Heating Frasch Sulphur Mine Water Using Waste Heat (1977).
Sulfur is used in the vulcanisation of black rubber (Improvement in India Rubber Fabrics (1844)), as a fungicide and in black gunpowder.
Most sulfur is, however, used in the production of sulfuric acid. which is perhaps the most important chemical manufactured by western civilisations.
The Leathers’ Chemical plant in Seaton Carew UK produced H2SO4 by the lead chamber Process: Improvements In Or Relating To The Manufacture Of Sulphuric Acid By The Lead-Chamber Process Or By The Tower Process (1931). Nowadays sulfuric acid is produced by the contact process: http://tinyurl.com/y3hdyanu.
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All patent information has been obtained from Espacenet (European Patent Office).