Helium: how it is mined and where it is used
Helium is an inert gas, colorless and odorless, chemical element included in the periodic table. The first mention of helium dates back to 1868. Then the researchers Pierre Jules Jansen and Joseph Norman Lockyer observed the solar eclipse and carried out spectroscopy of the rays. When dividing the solar best into elements of different colors, they noticed a light yellow element, previously unknown to physicists. Later it turned out that it was helium.
Despite the fact that helium is the second most abundant in the universe after hydrogen, it is rarely found on Earth. Only in 1895, scientists from Scotland managed to isolate this substance from cleveite, a natural mineral.
Helium deposits
Today, helium is mined in the bowels of the earth, separating it from natural gas. In Russia, it is produced by a gas processing plant in Orenburg. The natural gas used at the plant contains only 0.055% helium, which is considered very low. Helium-rich gases are gases in which its content is at least 0.5%. If natural gas contains 0.1 to 0.5% helium, it is called a generic helium field.
In total, there are more than 40 billion cubic meters of helium on Earth. China, Russia, the USA, Algeria, and Qatar are the richest in helium. About 175 million cubic meters of helium are produced annually around the world. Russian deposits produce only 5 million cubic meters. Rich deposits of this gas have been discovered in Siberia and the Far East, but today its production has not been established there.
How is helium produced from natural gas?
The helium production process consists of two stages. First, natural gas is cooled, after which condensation occurs and helium concentrate is released - a substance that consists of 80% helium. After that, the resulting substance is purified from impurities (hydrogen, argon, methane, nitrogen). Various methods are used for purification.
Where is helium used?
This inert gas is an excellent conductor of electricity and heat, therefore it is widely used in many areas - in rocket science, aviation, the nuclear industry, and medicine. It is much lighter than air, so it is also used in aeronautics and scuba diving.
This gas is part of respiratory mixtures - it is not toxic, it can be inhaled without harm to health.
More recently, scientists have discovered another area of application for helium - in the nuclear industry. Helium is used as a heat conductor for nuclear reactors. In metallurgy, this gas is used as a protective agent during welding.
Helium reserves on Earth
According to experts, to meet such a large demand for helium, by 2030, 238-312 million cubic meters will be required annually. By this time, production will increase to only 213-238 million cubic meters per year, so some shortage of helium in production areas is expected. There is only one way out of this situation - to increase the amount of helium produced. In Russia, new enterprises for its production are already being built, mainly in the regions of Siberia.
Helium is the second ordinal element of D. I. Mendeleev's periodic system of chemical elements, with atomic number 2. It is located in the main subgroup of the eighth group, the first period of the periodic system. Heads the group of inert gases in the periodic table. It is designated by the symbol He (lat. Helium). The simple substance helium (CAS number: 7440-59-7) is an inert monatomic gas without color, taste or smell. Helium is one of the most abundant elements in the universe, second only to hydrogen. Helium is also the second lightest (after hydrogen) chemical element. Helium is extracted from natural gas by a low-temperature separation process - the so-called fractional distillation
On August 18, 1868, the French scientist Pierre Jansen, while in full solar eclipse in the Indian city of Guntur, first explored the chromosphere of the Sun. Jansen managed to adjust the spectroscope in such a way that the spectrum of the solar corona could be observed not only during an eclipse, but also on ordinary days. The very next day, spectroscopy of solar prominences, along with hydrogen lines - blue, green-blue and red - revealed a very bright yellow line, initially taken by Jansen and other astronomers who observed it for the sodium D line. Jansen immediately wrote about this to the French Academy of Sciences. Subsequently, it was found that the bright yellow line in the solar spectrum does not coincide with the sodium line and does not belong to any of the previously known chemical elements.
Two months later, on October 20, the English astronomer Norman Lockyer, not knowing about the developments of his French colleague, also conducted research on the solar spectrum. Having discovered an unknown yellow line with a wavelength of 588 nm (more precisely 587.56 nm), he designated it D3, since it was very close to the Fraunhofer lines D 1 (589.59 nm) and D 2 (588.99 nm) sodium. Two years later, Lockyer, together with the English chemist Edward Frankland, in collaboration with whom he worked, proposed giving the new element the name "helium" (from other Greek ἥλιος - "sun").
Interestingly, the letters of Jansen and Lockyer arrived at the French Academy of Sciences on the same day - October 24, 1868, but Lockyer's letter, written four days earlier, arrived several hours earlier. The next day, both letters were read at a meeting of the Academy. In honor of the new method for studying prominences, the French Academy decided to mint a medal. On one side of the medal, portraits of Jansen and Lockyer were carved over crossed laurel branches, and on the other, an image of the mythical sun god Apollo, ruling in a chariot with four horses galloping at full speed.
In 1881, the Italian Luigi Palmieri published a report on the discovery of helium in volcanic gases (fumaroles). He examined a light yellow oily substance that settled from gas jets on the edges of the crater of Vesuvius. Palmieri calcined this volcanic product in the flame of a Bunsen burner and observed the spectrum of gases released during this. The scientific community greeted this message with disbelief, since Palmieri described his experience vaguely. Many years later, small amounts of helium and argon were indeed found in the fumaroles.
Only 27 years after its initial discovery, helium was discovered on Earth - in 1895, the Scottish chemist William Ramsay, examining a sample of gas obtained from the decomposition of the mineral cleveite, found in its spectrum the same bright yellow line found earlier in the solar spectrum. The sample was sent for additional study to the famous English spectroscopy scientist William Crookes, who confirmed that the yellow line observed in the spectrum of the sample coincides with the D3 line of helium. On March 23, 1895, Ramsay sent a message about his discovery of helium on Earth to the Royal Society of London, as well as to the French Academy, through the famous chemist Marcelin Berthelot.
In 1896, Heinrich Kaiser, Siegbert Friedländer, and two years later Edward Bailey finally proved the presence of helium in the atmosphere.
Even before Ramsay, helium was also isolated by the American chemist Francis Hillebrand, but he mistakenly believed that he had received nitrogen and in a letter to Ramsay recognized him as the discovery priority.
Exploring various substances and minerals, Ramsay discovered that helium in them accompanies uranium and thorium. But only much later, in 1906, Rutherford and Royds established that the alpha particles of radioactive elements are helium nuclei. These studies initiated modern theory the structure of the atom.
Only in 1908, the Dutch physicist Heike Kamerling-Onnes managed to obtain liquid helium by throttling (see the Joule-Thomson effect), after the gas was pre-cooled in liquid hydrogen boiling under vacuum. Attempts to obtain solid helium remained unsuccessful for a long time even at a temperature of 0.71 K, which was achieved by the student of Kamerling-Onnes, the German physicist Willem Hendrik Keesom. Only in 1926, by applying pressure above 35 atm and cooling compressed helium in liquid helium boiling under rarefaction, did he succeed in isolating crystals.
In 1932, Keesom investigated the nature of the change in the heat capacity of liquid helium with temperature. He found that around 2.19 K, the slow and smooth rise in heat capacity is replaced by a sharp drop and the heat capacity curve takes the form of the Greek letter λ (lambda). Hence, the temperature at which the jump in heat capacity occurs is given the conditional name "λ-point". A more accurate temperature value at this point, established later, is 2.172 K. At the λ-point, deep and abrupt changes in the fundamental properties of liquid helium occur - one phase of liquid helium is replaced at this point by another, and without release of latent heat; a phase transition of the second order takes place. Above the temperature of the λ-point there is the so-called helium-I, and below it - helium-II.
In 1938, the Soviet physicist Pyotr Leonidovich Kapitsa discovered the phenomenon of superfluidity of liquid helium-II, which consists in a sharp decrease in the viscosity coefficient, as a result of which helium flows almost without friction. Here is what he wrote in one of his reports about the discovery of this phenomenon.
origin of name
From Greek. ἥλιος - "Sun" (see Helios). Curious is the fact that in the name of the element, the ending “-iy”, characteristic of metals, was used (in Latin “-um” - “Helium”), since Lockyer assumed that the element he discovered was a metal. By analogy with other noble gases, it would be logical to give it the name "Helion" ("Helion"). IN modern science The name "helion" was assigned to the nucleus of the light isotope of helium - helium-3.
Prevalence
In the Universe
Helium is the second most abundant in the Universe after hydrogen - about 23% by mass. However, helium is rare on Earth. Almost all the helium in the universe was formed in the first few minutes after the Big Bang, during the primary nucleosynthesis. In the modern Universe, almost all new helium is formed as a result of thermonuclear fusion from hydrogen in the interiors of stars (see proton-proton cycle, carbon-nitrogen cycle). On Earth, it is formed as a result of alpha decay of heavy elements (alpha particles emitted during alpha decay are helium-4 nuclei). Part of the helium that arose during alpha decay and seeps through the rocks of the earth's crust is captured by natural gas, the concentration of helium in which can reach 7% of the volume and above.
Earth's crust
Within the framework of the eighth group, helium ranks second in terms of content in the earth's crust (after argon). The helium content in the atmosphere (formed as a result of the decay of Ac, Th, U) is 5.27×10−4% by volume, 7.24×10−5% by mass. Helium reserves in the atmosphere, lithosphere and hydrosphere are estimated at 5×1014 m³. Helium-bearing natural gases usually contain up to 2% helium by volume. Extremely rare are accumulations of gases, the helium content of which reaches 8 - 16%. The average content of helium in the terrestrial matter is 3 g/t. The highest concentration of helium is observed in minerals containing uranium, thorium and samarium: kleveite, fergusonite, samarskite, gadolinite, monazite (monazite sands in India and Brazil), thorianite. The helium content in these minerals is 0.8 - 3.5 l/kg, and in thorianite it reaches 10.5 l/kg
Definition
Qualitatively, helium is determined by analyzing emission spectra (characteristic lines at 587.56 nm and 388.86 nm), quantitatively by mass spectrometric and chromatographic methods of analysis, as well as methods based on measuring physical properties(density, thermal conductivity, etc.)
Chemical properties
Helium is the least chemically active element of the eighth group of the periodic table (inert gases). Many helium compounds exist only in the gas phase in the form of so-called excimer molecules, in which excited electronic states are stable and the ground state is unstable. Helium forms diatomic molecules He 2 +, fluoride HeF, chloride HeCl (excimer molecules are formed by the action of an electric discharge or ultraviolet radiation on a mixture of helium with fluorine or chlorine). Known chemical compound helium LiHe (possibly, the connection LiHe 7
Receipt
In industry, helium is obtained from helium-containing natural gases (at present, deposits containing > 0.1% helium are mainly exploited). Helium is separated from other gases by deep cooling, using the fact that it is more difficult to liquefy than all other gases. Cooling is carried out by throttling in several stages, cleaning it from CO 2 and hydrocarbons. The result is a mixture of helium, neon and hydrogen. This mixture, the so-called. raw helium, (He - 70-90% vol.) is purified from hydrogen (4-5%) with CuO at 650-800 K. Final purification is achieved by cooling the remaining mixture with N2 boiling under vacuum and adsorption of impurities on active carbon in adsorbers, also cooled by liquid N2. They produce helium of technical purity (99.80% by volume helium) and high purity (99.985%). In Russia, gaseous helium is obtained from natural and petroleum gases. Currently, helium is extracted at the helium plant of OOO Gazprom dobycha Orenburg in Orenburg from gas with low content helium (up to 0.055% vol.), so Russian helium has a high cost. An urgent problem is the development and complex processing of natural gases from large deposits of Eastern Siberia with a high content of helium (0.15-1% vol.), which will significantly reduce its cost. The United States leads in helium production (140 million m³ per year), followed by Algeria (16 million m³). Russia ranks third in the world - 6 million m³ per year. The world reserves of helium amount to 45.6 billion m³.
Helium is a chemical element with atomic number 2 in the Periodic Table of Chemical Elements D.I. Mendeleev. Chemical formula He. Helium is an inert gas, colorless and odorless.
Helium is very common in the universe. It ranks second after hydrogen. But there is little helium on Earth.
Helium does not react with any chemical element. Its atoms do not even connect with each other. Helium does not burn.
Discovery of helium
Helium was discovered in 1868 during a solar eclipse. Moreover, this discovery was made simultaneously by two astronomers - the Frenchman Pierre Jules Jansen and the Englishman Joseph Norman Lockyer. In the spectrum of the solar corona, both independently discovered a yellow line that did not belong to any of the elements known at that time. Lockyer suggested in 1871 that a new chemical element is present on the Sun. And in 1895 Scottish chemist William Ramsay first isolated the gas from the radioactive mineral cleveite. Exactly the same yellow line was present in the spectrum of this gas. The new element was given a name Helios is the sun.
Getting helium
Helium is obtained from natural helium-bearing gases by deep cooling. Helium extraction is carried out in two stages. The first stage is the production of helium concentrate by condensation at low temperature. And the second stage is the purification of the helium concentrate from methane, hydrogen, nitrogen, neon, argon.
All major world helium reserves are located in Algeria, Qatar, the USA and Russia. largest manufacturer helium - USA. Little helium is produced in Russia, since its main deposits are located in the little-developed fields of the Far East and Eastern Siberia.
Helium application
Helium has high electrical and thermal conductivity. In addition, it has a very low boiling point, minus 268.94 o C.
The scope of helium is very wide.
A mixture of gaseous helium with oxygen is used to relieve asthma attacks. Helium is much less soluble in blood than nitrogen. Therefore, it is used in breathing mixtures supplied to divers during deep-sea diving to create an artificial atmosphere for spacecraft and stations.
Many technological processes in production, it is impossible to carry out in an air environment due to the possibility of reacting with air gases of the feedstock or the resulting product. And here gaseous helium comes to the rescue, with the help of which special protective environments are created.
Separate stages of obtaining nuclear fuel take place in a helium protective environment. Fuel elements of nuclear reactors are also transported and stored in containers filled with gel. Helium is used to detect leaks in nuclear reactors. Helium is used in gas thermometers, high voltage switches, neutron counters, and for gas lubrication of bearings.
As an inert medium, helium is used in arc welding.
Airships and balloons are filled with helium.
Helium is non-toxic. And inhaling a small amount of helium along with the air is harmless.
Helium (He) has the second abundance in the universe after hydrogen. Thanks to the excellent properties helium technical Today it is used in many areas of our life.
Gas properties
Despite the wide distribution outside our planet, this chemical element is not so common directly on Earth. Its highest concentration is in natural gas, from where, in fact, technical helium is extracted.
Under normal conditions, it is an inert gas with the lowest boiling point of all substances. Like most industrial gases, it is colorless, tasteless and odorless. In this regard, it is close in properties to argon, but differs from another gas - acetylene, which has a bright smell, and is also explosive. By the way, you can read about acetylene in the article: dissolved acetylene for cutting and welding metals.
He is mined by deep cooling from helium-containing natural gases. The process is carried out in several stages. First, carbon dioxide and other hydrocarbons are separated, resulting in the so-called crude helium with impurities of hydrogen and neon. The final purification takes place with the use of liquid nitrogen and adsorption of the remaining impurities on activated carbon.
The figure shows a diagram of a device for the production of helium from natural gas
Where is technical helium used?
Today, many industries cannot do without this gas. It is used in magnetic tomographs, microelectronics, science, medicine, for cooling nuclear reactors, filling balloons and in many other areas. Since helium is absolutely safe due to its incombustibility, it is filled with aeronautical vessels, such as balloons and airships.
This is what the weld seam looks like when helium is used as the shielding gas
Main brands
There are several grades of technical He, which differ in the volume fraction of this element and the scope.
- Gaseous technical(99.8%). A share of 0.2% is occupied by impurities of nitrogen, hydrogen, oxygen and argon. Most commonly used in the entertainment industry when filling balloons.
- Mark B(99.990%). Contains a small amount of impurities of hydrogen, oxygen, argon, nitrogen and neon. It is used to fill cryogenic devices and systems.
- Grade A(99.995%). Used to fill the fuel components of nuclear reactors to ensure optimal heat removal.
- Brand 4.6(99.996). Designed to meet laser manufacturer's gas purity requirements.
- Brand 5.5(99.9995%). Ultra-pure He has gained popularity in areas where the complete absence of air impurities is necessary, since they can negatively affect technological processes.
- Mark 6.0(99.9999%). It is used in laser technologies, chromatography, that is, where the absence of any impurities is critical.
- Mark 7.0(99.999990%). The volume fraction of impurities is no more than 0.00001%, which allows it to be used in ultra-precise and gas purity-demanding developments.
- Liquid. This substance in a liquid state has found application in the field of high technology. This is due to the fact that at the temperature of liquid He, superconductors conduct electricity without additional heating, creating powerful magnetic fields. Used in nuclear magnetic resonance research.
Transport and storage
The gas is stored and transported in brown steel cylinders with right hand threads. Most often, helium containers with a volume of 10 and 40 liters are used. During transportation, the cylinders are placed in specialized containers. If the basic rules are followed, helium cylinders can be transported by any mode of transport.
Helium, usually produced by radioactive decay uranium-238 and uranium-235 was found in the solar atmosphere 13 years earlier than on Earth. This gas has the lowest critical values, the lowest boiling point, the lowest heat of evaporation and melting. As for the melting point of helium, at normal pressure it does not exist at all. There is no other substance like it in nature...
Helium is an unusual element, and its history is somewhat mysterious and incomprehensible. It was found in the Sun's atmosphere 13 years earlier than on Earth. More precisely, a bright yellow D line was discovered in the spectrum of the solar corona, and what was hidden behind it became reliably known only after helium was extracted from terrestrial minerals containing radioactive elements.
How is helium formed?
Mostly terrestrial helium is formed during the radioactive decay of uranium-238, uranium-235, thorium and unstable products of their decay. Helium in the earth's crust accumulates slowly. One ton of granite, containing 2 g of uranium and 10 g of thorium, produces only 0.09 mg of helium in a million years - half a cubic centimeter. In very few minerals rich in uranium and thorium, the helium content is quite high - a few cubic centimeters of helium per gram.
Most minerals undergo weathering, recrystallization, etc. processes over time, and helium leaves them. Helium bubbles released from crystalline structures partially dissolve in groundwater. Another part of the helium escapes into the atmosphere through the pores and cracks of minerals. The remaining gas molecules fall into underground traps, where they accumulate for tens, hundreds of millions of years. Layers of loose rocks act as traps here, the voids of which are filled with gas. The bed for such gas reservoirs is usually water or oil, and from above they are blocked by gas-tight strata of dense rocks.
Helium synthesis - the beginning of life
The bowels and atmosphere of our planet are poor in helium. But this does not mean that it is not enough everywhere in the Universe. According to modern estimates, 76% of the cosmic mass is hydrogen and 23% helium; on all other elements, only one percent remains. Thus, the world matter can be called hydrogen-helium. These two elements predominate in stars, planetary nebulae, and interstellar gas. The helium fusion reaction is the basis of the energy activity of stars, their glow. Consequently, helium synthesis can be considered the forefather of all reactions in nature, the root cause of life, light, heat and meteorological phenomena on Earth.
Natural gases are practically the only source of raw materials for the industrial production of helium. Helium is present in natural gases as a minor impurity. Its content does not exceed thousandths, hundredths, rarely - tenths of a percent. Large (1.5–10%) helium content of methane-nitrogen deposits is an extremely rare phenomenon. For separation from other gases, the exceptional volatility of helium associated with its low fluidization temperature is used. After all other components of natural gas are condensed by deep cooling, helium gas is pumped out. Then it is purified from impurities. The purity of the factory helium reaches 99.995%. Liquid helium is obtained by liquefying gaseous helium.
helium properties
gaseous helium- an inert gas without color, smell and taste. liquid helium- a colorless, odorless liquid with a boiling point at normal atmospheric pressure of 101.3 kPa (760 mm Hg) 4.215 K (minus 268.9 ° C) and a density of 124.9 kg / m 3.
Helium is non-toxic, non-flammable, non-explosive, but at high concentrations in the air it causes a state of oxygen deficiency and suffocation. Liquid helium is a low-boiling liquid that can cause frostbite on the skin and damage to the mucous membranes of the eyes.
helium atom(aka molecule) - the strongest of molecular structures. The orbits of its two electrons are exactly the same and pass extremely close to the nucleus. To expose a helium nucleus, you need to spend a record high energy (78.61 eV). From this follows the phenomenal chemical passivity of helium.
Helium molecules are non-polar. The forces of intermolecular interaction between them are extremely small - less than in any other substance. For this reason, helium has the lowest critical values, the lowest boiling point, and the lowest heat of evaporation and melting. As for the melting point of helium, at normal pressure it does not exist at all. Liquid helium at a temperature arbitrarily close to absolute zero does not solidify if, in addition to temperature, it is not affected by a pressure of 25 or more atmospheres. There is no other such substance in nature. It is the best conductor of electricity among gases and the second, after hydrogen, conductor of heat. Its heat capacity is very high, and its viscosity, on the contrary, is small.
Helium, airships, divers and nuclear power...
Helium was first used in Germany. In 1915, the Germans began to fill their airships bombing London with it. Soon, light but non-flammable helium became an indispensable filler for aeronautic vehicles. The decline in the airship industry, which began in the mid-1930s, led to a slight decline in helium production, but only by a short time. This gas increasingly attracted the attention of chemists, metallurgists and machine builders.
Another area of application of helium is due to the fact that many technological processes and operations cannot be carried out in an air environment. To avoid the interaction of the resulting substance (or feedstock) with air gases, special protective environments are created, and there is no more suitable gas for these purposes than helium.
in helium protective environment undergo separate stages of obtaining nuclear fuel. Fuel elements of nuclear reactors are stored and transported in containers filled with helium. With the help of special leak detectors, whose action is based on the exceptional diffusion ability of helium, they detect the slightest possibility of a leak in nuclear reactors and other systems under pressure or vacuum.
In scientific research and technology widely applied liquid helium. Ultra-low temperatures favor in-depth knowledge of matter and its structure - at higher temperatures, the subtle details of the energy spectra are masked by the thermal motion of atoms.
There are already superconducting solenoids made of special alloys that create strong magnetic fields (up to 300 thousand oersteds) at the temperature of liquid helium with negligible energy costs. At the temperature of liquid helium, many metals and alloys become superconductors. Superconducting cryotron relays are increasingly being used in the design of electronic computers. They are simple, reliable, very compact. Superconductors, and with them liquid helium, become essential for electronics. They are included in the design of detectors infrared radiation, molecular amplifiers (masers), optical quantum generators (lasers), devices for measuring microwave frequencies.
Helio-oxygen mixtures became a reliable means of preventing decompression sickness and gave a big gain in time when lifting divers. As is known, the solubility of gases in liquids, other things being equal, is directly proportional to pressure. Divers working under high pressure have much more nitrogen dissolved in their blood compared to normal conditions that exist on the surface of the water. When rising from a depth, when the pressure approaches normal, the solubility of nitrogen decreases, and its excess begins to be released. If the ascent is made quickly, the release of excess dissolved gases occurs so violently that the blood and water-rich tissues of the body, saturated with gas, foam with a mass of nitrogen bubbles - like champagne when a bottle is opened.
The formation of nitrogen bubbles in the blood vessels disrupts the functioning of the heart, their appearance in the brain disrupts its functions, and all this together leads to severe disorders in the body's vital functions and, as a result, to death. In order to prevent the development of the described phenomena, known as "caisson disease", the rise of divers, i.e. the transition from high blood pressure to normal, produced very slowly.
In this case, the excess of dissolved gases is released gradually and no painful disorders occur. With the use of artificial air, in which nitrogen is replaced by less soluble helium, the possibility of harmful disorders is almost completely eliminated. This allows divers to increase the depth of descent (up to 100 meters or more) and lengthen the time spent under water.
"Helium" air has a density three times less than the density of ordinary air. Therefore, it is easier to breathe such air than usual (the work of the respiratory muscles decreases). This circumstance is important in case of respiratory diseases. That's why helium air also applies in medicine in the treatment of asthma, suffocation and other diseases.
Not yet eternal, but already harmless
At the Los Alamos National Laboratory named after E. Fermi (New Mexico) developed new engine, which can seriously change the perception of the car as one of the main sources of pollution. With an efficiency comparable to an internal combustion engine (30-40%), it is devoid of its main disadvantages: moving parts that need lubrication to reduce friction and wear, and harmful to environment emissions of products of incomplete combustion of fuel.
In fact, we are talking about an improvement of the well-known external combustion engine, proposed by the Scottish priest R. Stirling back in 1816. This engine was not widely used in vehicles due to its more complex design compared to the internal combustion engine, greater material consumption and cost. But the thermoacoustic energy converter proposed by American scientists, in which compressed helium serves as the working medium, compares favorably with its predecessor by the absence of bulky heat exchangers that prevented its use in cars, and in the near future is able to become an environmentally acceptable alternative not only to an internal combustion engine, but also to a solar energy converter, a refrigerator, and an air conditioner. The scale of its application is still hard to imagine.
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