CS249491B1 - Modified bitumen-based mass - Google Patents

Abstract

Modified bitumen-based material intended for special purposes is prepared by modifying bitumen with tetrahydrosilicic acid and methylphenylsilicone oil. This prepared material has the ability to incorporate and fix even substances with water content, its workability time is shorter compared to unmodified bitumen, which limits the sedimentation of bound substances to a minimum. These properties of the material provide a basis for its use, e.g. in the field of fixation of low and medium radioactive waste.

Description

The present invention relates to the composition and preparation of a bitumen-based composition for special purposes. The modified mass prepared according to the invention appears to be particularly suitable for converting low and medium radioactive impacts into a solid, non-water washable form meeting long-term storage requirements.

The mass is characterized by the ability to wrap / per min. foaming (and also to bind substances with a certain water content (advantageous for fixing concentrated aqueous radioactive waste), has a reduced pot life, which virtually eliminates sedimentation of the bound substances. An advantageous feature of this modified mass is its relatively low cost.

Distillation bitumen in very many cases do not meet the requirements and requirements of practice. Therefore, their properties are improved, for example, by oxidation, compounding with additional butenes, by modifying the properties by the addition of various substances of different molecular weight.

These ways of modifying the bitumen properties are either in increasing the asphaltenes content and altering the structural composition of the distillation bitumen / oxidation with oxygen, air, sulfur, selenium, asphaltenes crosslinking by chlorine, compaction with other bitumens / or incorporating structured / polymer dispersions copolymers, such as polyethylene, polypropylene, styrene-butadiene copolymers, etc., in the bitumen mass, additive rubbing of rubber /, or in the incorporation of substances that build up the structure in the bitumen mass / urethanes, epoxy resins, styrene, etc., or others. special processes (precipitation of the distillation residue with calcium hydroxide in the presence of an olefin polymer, addition of additives to enhance the adhesion properties of bitumen, etc.), or a combination thereof.

The preparation of the modified bitumen-based mass according to the invention consists in forming a mixture containing 5 to 95% by weight, preferably 55 to 80% by weight. bitumen, penetration 10 to 300 p. j. at 25 ° C and a KG flour point of 36 to 110 °. 4 to 94 wt.%, Preferably 19 to 44 wt. % of tetra-silicic acid and up to 1 wt.%, preferably 0.001 to 0.01 wt. methyl phenyl silicone oil.

The bitumen is melted and heated to 50-200 [deg.] C. and selected amounts of tetra-silicic acid and methylphenylsilicone oil are added with stirring. After thorough mixing and subsequent cooling, a mass with a gel-like structure is formed. The properties of the mass (penetration, flash point, pot life, penetration index) can be varied by varying the amount of silicon-based feed additive, as well as the time and temperature of heating.

The density prepared in this manner seems particularly suitable for use in the field of fixation and storage of low and medium radioactive waste, both organic and concentrated aqueous, but this does not limit its use in other areas.

EXAMPLE

80% wt. bitumen / penetration 82 p.j. at 25 ° C, KG melt point 44 ° C /. The bitumen is heated to 120 ° C with stirring. After reaching this temperature, 20 wt. The mixture was stirred at 120 ° C for 5 minutes.

Example 2

70% wt. bitumen / penetration 86 p.j. at 25 ° C, KG steep point 45 ° c). The bitumen is heated to 130 ° C with stirring. Once this temperature is reached, 0.002% by weight is added under stirring. % methylphenylsilicone oil and 29.998 wt. tetrahydro silicic acid. The mixture was stirred at 130 ° C for 4 minutes.

Claims (1)

The present invention relates to a modified bitumen-based mass, characterized in that it contains from 5 to 95% by weight, preferably from 55 to 80% by weight, of the petroleum bitumen of the distillation and / or petroleum bitumen distillation oxidation point of KG 36 to 110 ° C and penetration 10 to 300 pj at 25 ° C, 4 to 94% by weight, preferably 19 to 44% by weight; % of silicic acid and up to 1 wt.%, preferably 0.001 to 0.01 wt. methyl phenyl silicone oil.