Helium is a lightweight gas and chemical element. Most of the world's helium comes from five natural gas fields in the United States: the Cliffside field in the Texas Panhandle; the Greenwood field in Kansas and Colorado; the Hugoton field in Kansas, Oklahoma and Texas; the Keyes field in Oklahoma; and the Panhandle field in Texas.
The five fields contain an estimated 180 billion cubic feet of helium. Helium plants in the United States produce about 2 billion cubic feet of helium each year. The U.S. government stores more than half of this amount underground in the Cliffside field for future use.
Natural gas from some wells contains up to eight percent helium. Helium is purified by cooling the natural gas until all gases except helium, argon, hydrogen and nitrogen change to liquid. Hydrogen is then burned out of the remaining mixture and argon is absorbed by charcoal at low temperatures.
Nitrogen often remains in helium as an impurity. Helium that is 99.995 percent pure is called grade A helium. Crude helium contains about half helium and half nitrogen.
Helium was first found in natural gas in Kansas in 1903. In 1929, the United States Bureau of Mines began producing helium at Amarillo, Tex. Since then, other government plants have been built in Kansas, New Mexico, Oklahoma and Texas. Privately owned helium plants are located in Kansas, Oklahoma and Texas. Helium is also produced in Saskatchewan, Canada.
Helium is called an inert gas or noble gas. These terms are used because helium does not combine with other elements.
Although helium is one of the most common elements in the universe, it makes up only a small fraction of the earth's matter. The sun and the stars are made mostly of helium and hydrogen. Helium makes up about 23 percent of the matter in the visible universe.
On the earth, our atmosphere contains about five parts of helium per million parts of air.
Evidence of helium in the sun was discovered by English astronomer Sir Joseph Lockyer in 1868. Lockyer found the evidence while studying the sun's light during an eclipse.
Lockyer invented the name helium from the Greek word helios, meaning sun.
Helium was first found on earth in 1895. The Scottish chemist Sir William Ramsay and the Swedish chemists Nils Langlet and Per Theodore Cleve found it in the mineral clevite.
The government's chief use of helium is in maintaining the proper pressures in rockets. Pressure must be maintained in rocket fuel tanks during flight, or the thin walls of the large tanks might collapse as the fuel drains from them. Helium also produces the pressure that forces fuel into rocket pumping systems.
The largest industrial use of helium is in heliarc welding, a type of electric arc welding. The inert helium keeps oxygen in the air from reaching the metal. If oxygen reaches the metal, it may cause the metal either to burn or to corrode.