The basis of the enrichment process is the photochemical reaction of selectively excited mercury atoms with oxygen in the presence of butadien-1,3.
As the result of this reaction nonvolatile mercury oxide is formed which is then accumulated on the internal surfaces of reaction cells. Next mercury is extracted from the cells and collected in a cooled trap. Mercury atoms are selectively excited by means of resonance radiation with the wavelength of 2,537 nm provided by a low pressure mercury lamp. Owing to the application of a number of physical and engineering solutions and employment of the "Foton" pilot plant we have succeeded in the automation of the enrichment process, in making it continuous and requiring the minimum of personnel.