RU2263983C2 - Composition for preparing radiation-protection material (options) - Google Patents

Abstract

FIELD: radiation protection.

SUBSTANCE: invention relates to protection against ionizing emission and consists in that composition for preparing radiation-protection material contains clay as binding material. In addition, composition contains caked product containing, wt %: lead oxide 15-40, barium oxide 35-65, silicon oxide 5-15, and refractory clay 5-20. Composition may further contain filler obtained by caking lead, silicon, barium, and tin oxides and, in this case, composition is constituted by, wt %: lead oxide 15-40, barium oxide 25-55, silicon oxide 5-15, tin oxide 10, and refractory clay 5-20.

EFFECT: enhanced efficiency in weakening ionizing emission and improved thermophysical properties.

2 cl, 3 tbl

Description

The invention relates to materials for protection against ionizing radiation and is intended to create protective structures and manufacture of biological protective equipment for personnel in the technical, medical and research fields of application of nuclear technology.

A known composition for producing radiation-protective material containing a polymer binder and a filler [and.with. USSR No. 1519440, class G 21 F 1/02, 1989].

The disadvantage of this composition is the low efficiency of attenuation of x-ray radiation obtained from it material.

A known building mixture, including glass binder - ground glass, a glass filler - crushed glass and liquid glass and the addition of gypsum in the following ratio of components, wt.%: SiO ₂ 58.1-70.5; In ₂ O ₃ 0.1-3.7; CaO 0.2-6.0; BaO - 0.2-12.0; PbO 0.2-13.0; Al ₂ O ₃ 2-6; Na ₂ O 3-7; K ₂ O 8-10, water glass with a density of 1.21-1.25 g / cm and the addition of gypsum in the following ratio of components, parts by weight: ground glass 100, crushed glass 50-300, water glass 30-60 and gypsum 1-26 [RU, patent No. 2187483, class. From 04 to 28/26, publ. August 20, 2002 (prototype)].

The disadvantages of this composition are that the use of mechanical mixtures of oxides having various thermodynamic characteristics leads to a decrease in strength and deterioration of the thermophysical characteristics of the final product, and with long-term use is accompanied by an uncontrolled change in its properties.

The technical result of the invention is to optimize the attenuation efficiency of the resulting material of ionizing radiation depending on the spectrum, as well as to increase the thermophysical properties and mechanical strength of the protective structures.

The technical result is achieved in that the composition for producing a radiation-protective material according to the first embodiment, containing a binder and lead, silicon and barium oxides as a filler, according to the invention, contains a filler obtained by sintering from lead, silicon and barium oxides and as a binder, refractory clay the following ratio of components, wt.%:

Lead oxide 15-40 Barium oxide 35-65 Silica 5-15 Fire-clay 5-20

According to a second embodiment of the invention, it is new that it contains a filler obtained by sintering from oxides of lead, silicon, barium and tin and as a binder, refractory clay in the following ratio of components, wt.%:

Lead oxide 15-40 Barium oxide 25-55 Silica 5-15 Tin oxide 10 Fire-clay 5-20

Comparative analysis with the prototype allows us to conclude that the claimed composition differs from the prototype in the qualitative composition and quantitative ratio of the components. The combination of these two technical solutions in one application is due to the fact that both inventions solve the same problem in essentially the same way, but cannot be combined by one claim.

Table 1 shows the compositions of radiation protective materials.

Table 1. No. The content of the components of the fillers,% wt. Pbo BaO ^* SiO ₂ fire-clay Sno ₂ B1 15.0 65.0 15.0 5.0 - B2 33.0 45.0 9.0 13.0 - Bz 40.0 35.0 5.0 20.0 - B4 33.0 35.0 9.0 13.0 10.0

As components of the filler, solid solutions of lead and silicon oxides in barium silicates are used; 10% BaO can be replaced by 10% SnO ₂ tin oxide _.

The filler is prepared as follows. Samples of metal oxides are subjected to joint grinding in a ceramic ball mill. Water is added to the resulting material and mixed thoroughly, after which the tablets are pressed under pressure of 100-200 kg / cm ² . Dried tablets for 12 hours at a temperature of 60 ° C are placed in an oven and gradually increase the temperature to a predetermined temperature (1000-1200 ° C) within an hour, depending on the composition. The sintering time of the sintering material is 30-90 minutes and is determined by the degree of approximation of the sintering temperature of the material to the solidus line of the oxide system formed by the filler components. In the process of sintering a material consisting of metal oxides, the synthesis of strong chemical compounds - barium silicates (n-BaO-SiO ₂ ) and, as follows from the state diagram of the m-PbO-SiOr n-BaO-SiO _{2 system} , dissolution of oxides in it lead and silicon, as evidenced by x-ray phase analysis of filler samples.

Obtained by sintering of metal oxides, the filler is milled to a fraction of 0.15 mm, which is the starting material for the production of ceramics.

To obtain ceramics, 5-20% of refractory clay is introduced into the filler, the resulting mixture is moistened and thoroughly mixed, and then cylinders with a diameter of 50 mm and various heights are pressed, the dried cylinders are fired in an oven at a temperature of 900-1200 ° C for 3 hours.

The resulting products were tested for their ability to absorb ionizing radiation.

The X-ray protective properties of the materials were tested using a source of a gamma radiation line with an energy of 0.662 MeV - ¹³⁵ Cs and an RUP-3 X-ray apparatus with anode voltage of 250 kV and a current of 8 mA.

The test results of materials for the ability to attenuate x-ray and gamma radiation are given in tables 2, 3.

table 2
Characteristics of materials for the absorption of gamma radiation Material Z _eff E _γ = 0.662 MeV μ E _γ , = 0.662 MeV μ _m E _γ = 0.662 MeV T pl., ° C Density ρ, g / cm ³ Pb 82 1.118 0.0986 327 11.34 B1 59 0.354 0.0868 1200 4.08 B2 63 0.379 0.0865 1100 4.38 B3 73 0.426 0.0973 950 4.39 B4 62 0.365 0.0863 1100 4.36 Table 3
Multiplicity of attenuation of the exposure dose rate for an X-ray source with anode voltage U = 250 kV and anode current of 8 mA Designed by Material B1 B2 B3 B4 D mm 3.5 7.0 13.5 3.5 7.0 13.8 3.5 7.7 13.2 3.5 7.0 13.8 TO 6.1 12.7 17.6 7.5 12.3 23.3 5.7 13.2 20.4 7.1 11.9 21.7 Control Material Al Cu Pb D mm 3.5 7.0 13.5 3.5 7.0 12.0 3.5 7.0 13.5 TO 1.1 1.2 1.9 3.8 6.0 9.2 13.2 20. 0 26.2

From the above data it is seen that the use of the invention provides a protective material with optimized characteristics in terms of attenuation for x-ray and gamma radiation of various spectra. For X-ray sources with anode operating voltage of up to 300 kV, the materials provide protection comparable to a lead shield, with significantly lower protection weights 2.7–2.9 times.

From developed ceramic materials it is possible to produce crucibles, screens with a working temperature of up to 1200 ° C, as well as facing tiles with their subsequent glaze coating and other products. In addition, the filler and the ceramic-based end product have low toxicity and high resistance to environmental factors, as well as to changes in their characteristics over time, which allows the use of such materials for long-term structures, including long-term and final disposal of nuclear waste.

The proposed materials are transparent to electromagnetic radiation, which is confirmed by tests in a laboratory induction furnace with a frequency of 2500 hertz. Of these, it is possible to manufacture products (containers, pipes, tiles, etc.) designed to operate in a wide temperature range, and depending on the purpose, various binding materials can be selected.

Claims (2)

1. A composition for producing a radiation-protective material containing a binder and lead, silicon and barium oxides as a filler, characterized in that it contains a filler obtained by sintering from lead, silicon and barium oxides and as a binder, refractory clay in the following ratio of components, wt.%: lead oxide 15-40; barium oxide 35-65; silica 5-15; refractory clay 5-20. 2. A composition for producing a radiation-protective material containing a binder and lead, silicon and barium oxides as a filler, characterized in that it contains a filler obtained by sintering from lead, silicon, barium and tin oxides and as a binder, refractory clay in the following ratio components, wt.%: lead oxide 15-40; barium oxide 25-55; silica 5-15; tin oxide 10; refractory clay 5-20.