about sulphur

An Introduction to Sulphur

Sulphur is a non-metallic chemical element identified by the letter S. For a list of sulphur's chemical properties, please click here. Sulphur is a valuable commodity and integral component of the world economy used to manufacture numerous products including fertilizers and other chemicals. For a list of sulphur uses click here. Sulphur also is a vital nutrient for crops, animals and people.

Sulphur occurs naturally in the environment and is the thirteenth most abundant element in the earth's crust. It can be mined in its elemental form, though this production has reduced significantly in recent years. Since early in the 20th Century, the Frasch process has been used as a method to extract sulphur from underground deposits, when it displaced traditional mining principally in Sicily. Most of the world's sulphur was obtained this way until the late 20th century, when sulphur's recovery from petroleum and gas sources (recovered sulphur) became more commonplace. As of 2011, the only operating Frasch mines worldwide are in Poland and since 2010 in Mexico. The last mine operating in the United States closed in 2000. A Frasch mine in Iraq closed in 2003.

Sulphur that is mined or recovered from oil and gas production is known as brimstone, or elemental sulphur. Sulphur produced as a by-product of ferrous and non-ferrous metal smelting is produced in the form of sulphuric acid. A smaller volume is produced as sulphur dioxide, which is also emitted from petroleum products used in vehicles and at some power plants. Plants absorb sulphur from the soil in sulphate form.

Elemental sulphur is produced all over the world. Largest production occurs where sour (meaning sulphur-rich) gas and oil is processed and refined: United States, Canada, the Former Soviet Union, and West Asia.

Over half of elemental sulphur production is traded internationally. China is the world's largest importer, followed by Morocco and the United States. Canada is the largest exporter, followed by Russia and Saudi Arabia.

Well over half of global sulphuric acid production comes from burning elemental sulphur at points of consumption, with most of the remainder produced at non-ferrous metals smelters and pyrites mines. East Asia, led by China, is the largest overall acid producer, stemming largely from rapid growth. It is followed by North America, Africa, and Latin America. Practically all traded acid is from smelters. Western Europe is the largest acid trading region, followed by East Asia and North America.

Sulphur is the primary source to produce sulphuric acid, the world's most used chemical and a versatile mineral acid used as an essential intermediate in many processes in the chemical and manufacturing industries. Sulphuric acid is used by the fertilizer industry to manufacture primarily phosphates, and also nitrogen, potassium, and sulphate fertilizers. Sulphur is also used in many other industries including non-ferrous metals, pigments, fibers, hydrofluoric acid, carbon disulphide, pharmaceuticals, agricultural pesticides, personal care products, cosmetics, synthetic rubber vulcanization, water treatment, and steel pickling.

Like nitrogen, phosphorus and potassium, sulphur is one of the essential plant nutrients. It contributes to an increase in crop yields in three different ways: 1) it provides a direct nutritive value, 2) it provides indirect nutritive value as soil amendment, especially for calcareous and saline alkali soils, and 3) it improves the use efficiency of other essential plant nutrients, particularly nitrogen and phosphorus. In general, sulphur has similar functions in plant growth and nutrition as nitrogen.

The incidence of soil sulphur deficiency has rapidly increased in recent years. Three major factors are responsible for increased sulphur deficiency: a) intensified cropping systems worldwide demand higher sulphur nutrient availability; b) increased use of high-analysis, sulphur-free fertilizers, and c) reduction of sulphur dioxide emissions, particularly in developed regions, reduces atmospheric sulphur deposition, a "natural" sulphur source. For more information on sulphur fertilizers, please see TSI's Publications.

Sulphur asphalt (SA), sometimes referred to as sulphur bitumen, sulphur extended asphalt or SEA, is a viable alternative for asphalt road binder. Sulphur's unique properties to improve the characteristics of asphalt have been known for more than a century. For more information on sulphur asphalt, please see TSI's Publications.