METHOD OF CONDITIONING RADIOACTIVE WASTES OF HEAT-INSULATING MATERIALS Russian patent published in 2015 - IPC G21F9/28 

FIELD: chemistry.

SUBSTANCE: in claimed method to obtain magnesia compounds as binding material used is caustic magnesite powder, for instance of grade PMK-87, tempering of materials is realised with magnesium chloride solution, process of magnesia cement mixture is carried out in the following succession. 85÷90 l of MgCl₂·6H₂O solution with density 1.12÷1.15 g/cm³ are supplied into metal 200-litre barrel by means of dosing device. After that, 165÷175 kg of preliminarily crushed heat-insulating material (HIM) with particle size to 1 mm are dosed into barrel with "a" solution in portions with weight 9÷10 kg. After that, 60÷65 of caustic magnesite powder are supplied into barrel, containing mixture "b", in portions with weight 6÷7 kg with constant mixing until homogeneous mixture is obtained.

EFFECT: possibility of obtaining strong water-resistant compounds with high degree of filling heat-insulating materials at rate of leaching caesium-137 from obtained compounds 5-10 times lower than set permissible limit for cement compounds without necessity to add sorption additive.

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