Helium is the inert one-atomic gas which does not have color, taste and a smell. One of the most widespread elements in the Universe, the second after hydrogen. Helium is extracted from natural gas by process of low-temperature division — so-called fractional distillation.
Instruction
1. The atomic nucleus of helium consists of two protons and (usually) two neutrons, around it two electrons rotate. Atom of helium is less by the size, than lighter atom of hydrogen with one proton and an electron as the big force of an attraction of a kernel of helium attracts electrons closer. Though it is simpler to assume that electrons, rotate around a kernel on a circular orbit, forming "cloud", the place of the most probable arrangement of electrons. The helium isotopes containing 2 protons and 2 electrons may contain from 1 to 4 neutrons.
2. In the industry helium is received from natural gases in which it contains. From other gases helium is separated by method of deep cooling, using that it is liquefied most difficultly than other gases.
3. At first make cooling with a drosselirovaniye which takes place in several stages. During this process, helium is purified from carbon dioxide and other hydrocarbons. As a result mix of helium, hydrogen and neon turns out. The received mix is called ""crude"" helium. Helium content in mix is from 70 to 90%.
4. Then mix of crude helium undergoes cleaning at which there is a removal of hydrogen from it. Hydrogen from mix is removed by means of copper oxide.
5. Further final purification of helium is reached by cooling of the remained mix, the nitrogen boiling under a vacuum and the subsequent adsorption of the available impurity on active coal in adsorbers which are also cooled with liquid nitrogen. Usually helium is received two types: technical purity (content of helium of 99.80%), and high purity (content of helium of 99.985%).