WHAT IS sulphur(sulfur) ?
Sulphur is a non-metallic chemical element in the world and is identified by the letter S. Sulphur is a valuable commodity and integral component of the world economy. It is often used to manufacture numerous products including industry fertilizers, chemicals, paints, rubber products, medicines, fibers, sugar, detergents, plastics, paper and many other products. Sulphur also is a vital nutrient for crops, animals, and people. Sulfur is a solid chemical element with atomic number 16 on the periodic table. It is an abundant non-metal that occurs naturally as an element in its native form. Sulfur also commonly occurs in combined forms as either sulfide or sulfate minerals. Now that we are aware of some of the basics about sulfur, it is time to discuss the processes involved in exporting it. Where does sulphur come from? 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, although this method has declined over the last decade to less than 2% of world production. Most elemental sulphur is obtained as a co-product recovered from oil and gas production. Are there different forms of sulphur? Not really. Sulphur is an element. Sulphur that is mined or recovered from oil and gas production is known as elemental sulphur, or brimstone. Sulphur can be combined with other elements to form various compounds. Sulphur compounds, such as sulphuric acid, also are produced as a by-product of ferrous and non-ferrous metal smelting. Other compounds, such as sulphur dioxide, may be emitted from petroleum products used in cars and coal generating electricity. Plants absorb sulphur from the soil as sulphate. Where is sulphur produced? Elemental sulphur is produced the world over. The largest production occurs where sour gas and oil is processed and refined: United State, Canada, the Former Soviet Union, and West Asia. Sulphur Importing Countries According to the Observatory of Economic Complexity (OEC), the world’s biggest sulfur importers are China (16%), the Democratic Republic of the Congo (15%), South Africa (14%) and Indonesia (13%). The only other two countries over 5% are Australia (6.6%) and Cuba (6.4%). The biggest sulfur importer in South America is Chile (1.9%) and in Europe, it is a tie between Germany and the Czech Republic (1.4%).
How and where is sulphuric acid produced? Well over half of the global sulphuric acid production comes from burning elemental sulphur in special equipment at points of consumption. Most of the remainder is recovered at non-ferrous metals smelters and pyrites mines. East Asia, led by China, is the largest overall acid producer, stemming largely from its rapid economic growth. It is followed by North America, Africa, and Latin America. Is sulphuric acid traded internationally? Yes. Practically all traded acid is from metals smelters. Western Europe is the largest acid trading region, followed by East Asia and North America. What is sulphur used for? Sulphur is the primary source in the production of sulphuric acid, the world’s most widely used chemical. Sulphuric acid is an essential intermediate in many processes in the chemical and manufacturing industries. Sulphuric acid also is used by the fertilizer industry to manufacture primarily phosphates, nitrogen, potassium, and sulphate fertilizers. It is also used in manufacturing other products, 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. Why do plants need sulphur? Following nitrogen, phosphorus, and potassium, sulphur is an essential plant nutrient. 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 amendments, especially for calcareous and saline alkali soils; and 3) it improves the use efficiency of other essential plant nutrients, particularly nitrogen and phosphorus. Sulphur is necessary for plant growth and nutrition. How much sulphur do plants need? Most crops remove 15 to 30 kg for sulphur per hectare (S/ha). Oil crops, legumes, forages, and some vegetables require more sulphur than phosphorus for optimal yield and quality. Plants contain as much sulphur as phosphorus, with an average content of approximately 0.25%. Usual recommendations for correcting deficiency are 15 to 30 kg S/ha for cereal crops and silage grass; and 25 to 50 kg S/ha for oil crops, legume, sugarcane, and some vegetable crops. For more detailed information about sulphur demand for specific crops and regions, please see The Sulphur Institute’s Publications. Why is sulphur deficiency becoming severe in agricultural production in recent years? Factors contributing to increasing sulphur deficiencies include:
- More sulphur is removed from the soil as a result of an increase in agricultural production by increasing fertilizer use, intensifying cropping systems, promoting high-yield crop varieties, and improving irrigation.
- Less sulphur is added to the soil due to the increasing proportions of high-analysis, sulphur-free fertilizers, such as urea, diammonium phosphate (DAP), and potassium chloride; decreasing use of traditional organic manures and sulphur-containing fertilizers, such as single superphosphate and ammonium sulphate, and sulphur-containing pesticides.
- Lower sulphur dioxide emissions are reducing atmospheric availability, one of the important historical sources of sulphur for agriculture around industrial areas. More stringent environmental regulations in Western Europe, North America and increasingly in developing countries have reduced atmospheric sulphur deposition, which leads to sulphur deficiency in agriculture.
What is the role of sulphur fertilizer in crop production? Both the yield and quality of crops grown on sulphur-deficient soils are reduced unless sulphur is included in the fertilizer treatment. Sulphur fertilizer can increase crop yields and quality and result in significant economic returns to producers. Sulphur fertilization also improves overall fertilizer efficiency. What sulphur fertilizers are available? Most sulphur-containing fertilizer materials generally can be divided into two groups: 1) fertilizers containing sulphate, and 2) fertilizers containing elemental sulphur. Sulphate-containing fertilizers provide most of the fertilizer sulphur applied to soils. The most significant and popular sources are ammonium sulphate, single superphosphate (SSP), potassium sulphate, potassium magnesium sulphate, and gypsum. These materials have the advantages of supplying sulphur primarily as a component of multi-nutrient fertilizers in a sulphate form that is immediately available for plant uptake. Elemental sulphur-containing fertilizers are the most concentrated sulphur carriers. However, elemental sulphur has to be oxidized into sulphate form before plant products, such as granular sulphur-bentonite, have improved the effectiveness of elemental sulphur by providing elemental sulphur in an acceptable physical form so that it can be used for direct application and bulk blending with little dust and be converted more readily to sulphate form in the soil. Most manufacturers offer specially formulated sulphur containing nitrogen or nitrogen phosphorus potassium (NPK) fertilizers, such as urea-sulphur, elemental sulphur, modified/enriched monoammonium phosphate (MAP)/diammonium phosphate (DAP)/NPK fertilizers. What is sulphur asphalt (bitumen)? Sulphur asphalt (SA), sometimes referred to as sulphur bitumen or sulphur extended asphalt (SEA), is a viable alternative for asphalt road binder, a process in which sulphur is used to extend asphalt materials as a means of energy conservation by minimizing asphalt demand. Combined with dried and heated stones and sand, either asphalt or SA can be used to make “hot mix” paving materials and build road. For more detailed information about sulphur asphalt and its use as construction materials worldwide, please see TSI’s Publications. What is sulphur concrete? Sulphur concrete is a relatively new corrosion-resistant material that contains stones, sand, mineral filter, and sulphur polymer cement (chemically modified sulphur) binder. Sulphur concrete is mixed and placed at an elevated temperature. It rapidly gains high strength over a few hours of cooling and provides an economic, long-term performance in many harsh environments.