METHOD PURIFYING SAND FROM RADIOACTIVE NUCLIDES Russian patent published in 2010 - IPC G21F9/28 

FIELD: physics, nuclear.

SUBSTANCE: invention relates to protection of the environment, rehabilitation of territories contaminated with industrial radioactive isotopes (radioactive nuclides). The method of purifying sand from radioactive nuclides involves initial breaking of soil aggregates, the surface muddy layer covering sand grains and pebbles. After separation and washing, the pebbles are taken out of the process cycle. Pulp is subjected to reactant treatment, at the end of which the reactant solution is separated. The pulp is washed with water. The separated reactant solution is mixed with water from washing the pulp, and radioactive nuclides are precipitated from the obtained mixture and then taken to the storage for radioactive wastes. After reactant treatment, the pulp is taken to a classification unit where it is separated into a sand and fine-dispersed fraction through water-gravitational separation. After dehydration, the sand fraction is taken to the selection site and the fine-dispersed fraction is subjected to reactant treatment in an autoclave at temperature higher than the boiling point of the reactant solution. After the reactant treatment, the reactant solution is separated. The fine-dispersed fraction is washed with water. The separated reactant solution is mixed with water from washing the fine-dispersed fraction. Radioactive nuclides are precipitated from the obtained mixture and then taken to the radioactive waste storage. After thickening and dehydration, the fine-dispersed fraction is returned to the selection site.

EFFECT: increased decontamination factor of sand with increase in content of the fine-dispersed fraction and complete purification of the fine-dispersed fraction to sanitary standards.

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