Sulfur is an element of the periodic table, a typical non-metal, yellow substance, consisting of small brittle crystals. Sulfur is widely distributed in nature in its pure form, in ores, in oil, natural waters, gases, coal, and shale. It plays an important role in human metabolism, chemosynthesis, and bacterial photosynthesis of plants. It is a component of proteins and vitamins.
In an interview to CentralAsia.news, a scientific observer and a well-known Turkmen scientist Allaberdi Ilyasov spoke about the areas of use of the highly profitable substance «sulfur» and the possibilities of Turkmenistan in organizing the commercial production of this universal chemical element.
History facts
Sulfur in its native state, as well as in the form of sulfur compounds, has been known since ancient times. People probably first felt the smell of burning sulfur, the suffocating effect of sulfur dioxide, and the disgusting smell of hydrogen sulfide in prehistoric times. The sulfur was used by priests as part of sacred incense during religious rites. Sulfur was considered the product of superhuman beings from the world of spirits or underground gods. A very long time ago, sulfur started to be used as part of various combustible mixtures for military purposes.
Around the 8th century, the Chinese began to use it in pyrotechnic mixtures, in particular, in mixtures such as gunpowder. The combustibility of sulfur, the ease with which it combines with metals to form sulfides, for example, on the surface of pieces of metal, explains why it was considered the «principle of combustibility» and an indispensable constituent of metal ores. During the period of Arabic alchemy, the mercury-sulfur theory of the composition of metals arose, according to which sulfur was considered an obligatory constituent of the «father» of all metals.
The elementary nature of sulfur was established by the French naturalist, the founder of modern chemistry, Antoine Laurent Lavoisier in his experiments on combustion. With the advent of gunpowder in Europe, the development of the extraction of natural sulfur, as well as the development of a method for obtaining it from pyrites started. Thus, the exact time of the discovery of sulfur has not been established, but this element has been used since before our era, which means it has been familiar to people since ancient times.
Component of production
Sulfur and its compounds play an important role in the production of macromolecular products, but in most cases, they are auxiliary, and not the main components. In the industry of polymeric materials, sulfur or its compounds are mainly used in the vulcanization of rubbers, as well as in the production of chlorosulfonated polyethylene, polysulfide synthetic rubbers, and cation exchangers.
In many countries of the world, research aimed at creating new structures and building materials, primarily floor and road surfaces, has been widely developed. In these compositions, sulfur plays the role of a polymer binder; therefore, such materials are called polymer-sulfur concrete and sulfur plastics.
In the new type of concrete, modified sulfur and cake are used as a binder instead of cement. These are waste products from the production of sulfuric acid. Sand, gravel, and other fillers are also added there.
Polymer concrete has a set of positive properties. First of all, these include a rapid set of strength, associated only with the period of cooling of the gray-concrete mixture; high wear resistance and strength; stability in acidic aggressive environments; low water absorption, and high frost resistance. A feature of sulfur concrete is the possibility of reusing defective structures by crushing, remelting, and molding.
«Sulfur» mountain of Turkmenistan
Large accumulations of native sulfur are not so common. More often it is present in some ores. Native sulfur ore is a rock interspersed with pure sulfur.
In Turkmenistan, a large sulfur deposit is located near Magdanly in Lebap province, until 2002 it was called Govurdak. The old name of the city is translated as the sulfur mountain («govur» — sulfur, «dag» — mountain). By the way, a large deposit of celestite was discovered in Magdanly. In addition to Turkmenistan, this mineral is mined only in nine countries of the world.
A large industrial sulfur deposit at the end of the 20th century was worked out by quarries and by the underground sulfur smelting method. The first geological description of the Turkmen deposit was made in 1927 by the geologist Alexander Danov. From 1929–to 1935, a significant amount of exploration work was carried out.
The formation of the deposit is associated with biochemical processes in lagoon-type sediments during the deposition of gypsum, anhydrite, halite, marl, and limestone. Sulfur was formed by the reduction of sulfate with the participation of anaerobic bacteria activated in the presence of hydrocarbons. This biological process led to the formation of hydrogen sulfide, which was then oxidized under near-surface conditions with the release of native sulfur, which settled to the bottom in the form of thin layers and scattered dissemination.
Ore mining and sulfur smelting at this spring began in 1934. From depths of more than 100 meters, sulfur was mined by the borehole method. Hot steam (165ºС) was supplied to the reservoir, after which the molten sulfur was pumped to the surface. The sulfur-bearing deposit is located at depths of 40-600 meters, the ore bodies are in the form of layers and sheet-like deposits, as well as stratified lenses and pockets.
However, all this does not mean that the Govurdak native sulfur has been forgotten. It is quite realistic and possible that soon it will again acquire industrial significance.
Areas of use
The areas of application of sulfur in industrial production and everyday life are very diverse. It is widely used in the chemical industry. According to various sources, about half of the use of sulfur falls on the production of sulfuric acid. Sulfuric acid salts are widely used in industry, agriculture, and everyday life.
Many salts of sulfuric acid contain water of crystallization. They are used as antiseptics for spraying plants and seed dressing in the fight against agricultural pests. In addition, sulfuric acid is used in the production of synthetic fibers, detergents, plastics, and explosives, it is also used to refine oil, sugar, vegetable oils, and fats, to obtain other acids and various chemicals. A large amount of sulfuric acid is used to pickle ferrous metals in the electrochemical industry.
Sulfur and its compounds are traditionally used in the pulp and paper industry to produce cellulose. A significant amount of sulfur is used in the production of matches and pyrotechnics.
Recently, sulfur has been increasingly used in the development of flooring and paving technologies. Sulfur concrete, containing up to 15 percent sulfur, is distinguished by corrosion and mechanical resistance. The high cost of concrete is offset by its durability. A technology for sulfur concrete and products made of it, in particular bricks and roofing tiles has been developed. Construction sulfur-containing mortar is used for repair, as well as for decorative work since its hardened form resembles granite.
Among other things, sulfur compounds serve as medicines. Sulfur is the basis of an ointment for the treatment of fungal skin diseases, to combat scabies. Sodium thiosulfate is used to combat scabies. Iron sulfate is used for anemia. Barium salt is used in x-ray examinations of the stomach and intestines. Potassium alum is used as a hemostatic agent for cuts. Sulfur is part of antibiotics, its compounds are used as radioprotective agents.
«Sulphur» pavement
The high mechanical strength and thermal stability of sulfur-based materials open up wide opportunities for their use as road surfaces. The technology for obtaining such materials is being developed in France, the USA, and Canada. In the US, sulfur-based pavements have been tested commercially.
The use of this coating showed that the new material is better than pure asphalt coatings in terms of its properties, as it can withstand high temperatures and heavy loads. It can be assumed that in the future such road surfaces will successfully compete with asphalt ones.
Sulfur as an additive is very relevant in reducing bitumen consumption. And a decrease in the bitumen content in sulfur-bitumen binders due to the addition of this chemical element, which is cheaper and available in significant quantities, reduces the cost of pavement installation.
The use of sulfur-bitumen binders makes it possible to widely use local sandy soils, weak stone materials, ash, and slag in road construction, which also provides a significant economic effect.
Highly profitable product of the world market
Sulfur is one of the important and large-tonnage types of chemical raw materials. It is widely used in the synthesis of many products — sulfuric acid, dyes, carbon disulfide, and the production of various substances and materials, such as rubber, cellulose, fertilizers, and oil additives.
Valuable specific properties of sulfur — hydrophobicity, bactericidal and binding properties, low toxicity — make it a highly profitable product on world markets.
