Keywords: Sulfur, Sulfuric acid, Sulfur market.

Sulfur has been known as an element with abundant useful properties since the earliest times and has become, through its conversion to sulfuric acid, the most important inorganic material in the chemical industry today. It is basically a large volume/low value commodity which has periodically been in short or 'tight' supply; this has resulted in substantial price fluctuations which consequently affected the economics of the chemical industry worldwide. During the periods of higher prices from the traditional or conventional sources of supply, alternative sulfur supply sources or different process routes have been developed and commercialised.

This paper reviews the recent developments which have led to the situation now facing the chemical industry, and more importantly the fertilizer industry (which is responsible for the consumption of over 50% of sulfur-in-all-forms on a world basis) where the tightness in the supply of sulfur has resulted in an average annual price increase of 18% over the last six years. The economics of sulfur production either in elemental form or as sulfuric acid, from the current major supply sources are compared, i.e. recovery from sour gas deposits. Frasch mining, non-ferrous metal smelter off-gases and pyrites roasting.

Future developments of sulfur supply and demand are reviewed to the end of the century and the consequent effect on prices assessed. It is clear that alternative sources or new processes for sulfur supply will be required to meet the increasing demand for sulfur before the end of the century. The economic viability of the most likely alternatives for additional sulfur supply are assessed on a present day basis and conclusions drawn as to which are most likely to reach commercial realisation.

Dr R Boyd, B.Sc., Ph.D. and T D Phillips, B.Sc., C.Chem., M.R.S.C., M.A.I.Ch.E., M.A.Cost.E., British Sulfur Corporation Ltd, London.

41 Pages, 13 Figures, 12 Tables, 8 References.