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| Position of the gas in the Periodic Table of the elements |
Use of helium
Diffusion of gas in nature
Although helium is the second most abundant element in the universe, after the hydrogen from which it is produced by nuclear fusion in the stars, on Earth it is very scarce, so it constitutes a limited natural resource, not renewable and perhaps the most easily exhausted, among the natural resources currently exploited, for its limited reserves.
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| Yellowish mineralization of carnotite in a sandstone |
As a product of radioactive decay, helium atoms, in the form of alpha particles, can be found trapped in the crystal lattice of uraniferous minerals, such as pitchblende or uraninite, carnotite, monazite and cleveite which is the first mineral in which this gas was identified.
Minimum percentages of helium, not imprisoned in a crystalline lattice, have been found in volcanic gases, and in spring waters in volcanic and geothermal areas, but above all it is found, present as "impurity", in some natural gas (methane) gisement.
As is known, helium is very light, so much so that it is used to fill rubber balloons, therefore after its generation within the earth's crust, and its possible release from the lattice structure of the mineral within which it is generated, it migrates to the Earth's surface, thus freeing itself in the atmosphere within which it disperses in the upper layers, arriving to constitute the major component in the upper part of the heterosphere [*], in order to then be definitively dispersed in space interplanetary.
Mining exploitation of helium
Of this rising gas it is possible to recover and extract from the underground only the minimum percentage that, in its upward migration, has encountered a trap, similarly as it happens with natural gas, and in fact all the helium deposits are actually gas deposits natural with a small fraction of helium mixed.
To date, the discovery of helium deposits is occasional, there is no prospecting or exploration activity specifically dedicated to the search for this gas, so the discovery of these deposits is a consequence of the hydrocarbon research activity, and collateral to the discovery of natural gas gisement, and are identified only after analyzing the composition of the natural gas found. It is not sure that this situation will change with the growth of its market demand and therefore of its value.
The cut-off value, that is the minimum quantity for which it can be economically claimed to be in the presence of a helium deposit, expressed as a percentage, is approximately equal to 0.3%. Consequently, to date, the production of helium makes it a subordinate by-product of the production of natural gas from which helium, on the surface, is first separated by cryogenic distillation (a process which in turn uses liquid helium) and then refined and liquefied for commercial uses. Liquid helium is transported and shipped worldwide in triple-walled and sealed tankers.
In which areas of the Earth are helium deposits located?
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| Worldwide distribution of countries with helium deposits, the color intensity is function of the amount of reserves |
The extraction and production of helium is mainly concentrated in three places, where about 75% of the helium consumed in the world is produced: Texas and Wyoming in the USA and Qatar, in the Arabian Gulf, the second largest producing nation in the world with a share of the 28% in 2018. Other countries, in the role of minor producers are Australia, China, Poland, Russia and Algeria, this has recently been taking a more relevant position with an increase in its production. Tanzania is also in the predicate of becoming a producer country. of gas.
The US dominates among consumer countries, consuming around 30% of world production.
The companies that market helium are few multinationals that form a small group, which operates in a vertical market, specialized in the production and trade of industrial gases that are not hydrocarbons, and have names that are not well known to those who are not introduced to the sector: Air Liquide (French), Air Products (American), Linde plc (German), Matheson Tri-Gas Inc. (Japanese), Iwatani Corporation (Japanese) and Messer Group (German).
[*] The heterosphere is the last subdivision of the Earth's atmosphere, whose base begins at about 100 km in height, and ends confining with the interplanetary space, in which the individual gas molecules are separated by the molecular diffusion mechanism; with increasing altitude, its components with lighter molecules become more abundant than those with heavier ones.
