Radiation protection curing agent and building material

Abstract

The present invention discloses a radiation-proof curing agent and building materials, wherein the radiation-proof curing agent comprises the following raw materials: 220 to 400 parts of water, 90 to 255 parts of sodium silicate, 10 to 55 parts of sodium hydroxide, 0 to 300 parts of electromagnetic radiation shielding materials, and 0 to 300 parts of neutron shielding materials. The present invention comprehensively utilizes materials such as ilmenite, barite, polyethylene, and boron carbide, and evenly mixes the finely ground radiation shielding materials, activators, and soil materials to form radiation-proof building materials that take into account strength, density, and radiation protection capabilities. The present invention can save construction costs in strong radiation environments such as lunar bases while ensuring that personnel and equipment on the lunar surface are protected from radiation hazards.

Description

Technical Field

[0001] The invention belongs to the field of building materials, and in particular relates to a radiation-proof curing agent and building materials. Background Art

[0002] The moon is rich in rare earth, titanium, aluminum and helium-3 resources. The development of the moon is the key to human space exploration. However, the high vacuum, large temperature difference and strong radiation environment on the lunar surface pose a huge threat to lunar exploration personnel and equipment. Since there is basically no atmosphere on the lunar surface, cosmic radiation and solar particles can reach the lunar surface directly, making the lunar surface radiation at a high level. The average lunar surface radiation is 200 times that of the surface radiation. Nuclear reactions between cosmic radiation particles and lunar surface materials will release neutrons, gamma rays, etc., that is, secondary radiation. The hazards of neutron radiation cannot be ignored. Its electrical neutrality makes it highly penetrable and cannot be intercepted by simple methods. It is very harmful to astronauts. Strong electromagnetic radiation such as gamma rays will not only kill biological cells, but also cause considerable damage to electronic devices and instruments. Therefore, the building materials used on the moon must have the ability to resist neutrons and electromagnetic radiation to ensure the safety of personnel and equipment in the lunar scientific research base.

[0003] In the field of radiation protection, there are many targeted strategies to cut off radiation paths to avoid radioactive sources from polluting the environment. The shielding effect of electromagnetic radiation shielding materials depends on the shielding material's ability to absorb electromagnetic waves and its energy conversion efficiency. In the design process, neutron shielding materials mainly consider how to slow down fast neutrons and absorb slow neutrons. For environments with high radiation intensity and complex radiation sources on the lunar surface, shielding of strong electromagnetic radiation and neutron radiation is still the primary task, but there is currently no design plan for radiation-proof building materials based on the utilization of lunar in-situ resources. Radiation-proof reinforcement materials based on high-abundance lunar resources such as lunar soil and ilmenite can save construction costs while ensuring the safety of personnel and property in radiation environments. This is an issue worthy of attention in the design of lunar infrastructure plans. Summary of the invention

[0004] The present invention provides a radiation-proof curing agent and building material, which can achieve radiation shielding while ensuring the mechanical properties of the reinforcement material, and have dual radiation protection performance, so as to at least solve the problem of the current lack of lunar surface radiation-proof building material design and solutions.

[0005] To achieve the above-mentioned purpose, the first aspect of the present invention provides a radiation protection curing agent, and the lunar soil reinforcement material includes the following raw materials in parts by weight: 220 to 400 parts of water, 90 to 255 parts of sodium silicate, 10 to 55 parts of sodium hydroxide, 0 to 300 parts of electromagnetic radiation shielding material, and 0 to 300 parts of neutron shielding material.

[0006] Furthermore, the SiO2 content in the sodium silicate is 52-56%.

[0007] Furthermore, the specific surface area of ​​the sodium silicate is 150 m 2 / g.

[0008] Furthermore, the electromagnetic radiation shielding material is a composite material formed by mixing ilmenite and barite in a weight ratio of (10-20): (10-20).

[0009] Furthermore, the iron content of the ilmenite is not less than 40%; the mass content of BaSO4 in the barite is not less than 98%.

[0010] Furthermore, the neutron shielding material is a composite material formed by mixing polyethylene powder and boron carbide in a weight ratio of (3-4): (8-9).

[0011] Furthermore, the polyethylene powder has a particle size of 50 to 70 μm and a density higher than 0.92 g / cm 3 The boron carbide particle size is less than 175 μm and the boron content is higher than 70%.

[0012] The second aspect of the present invention also discloses a radiation-proof building material, comprising the following raw materials: 220 to 400 parts of water, 90 to 255 parts of sodium silicate, 10 to 55 parts of sodium hydroxide, 0 to 300 parts of electromagnetic radiation shielding material, 1500 to 2000 parts of soil material, and 0 to 300 parts of neutron shielding material. The soil material has a particle size range of 0.01 μm to 1 mm, a median particle size of 51 to 138 μm, and a density of 1.10 to 1.89 g / cm.

[0013] Furthermore, the soil material contains 5% to 16% of alkaline oxides, and the alkaline oxides are composed of at least one of K2O, Na2O, and CaO.

[0014] Furthermore, the method for preparing the radiation-proof building material comprises the following steps:

[0015] S1. Dissolving sodium silicate and sodium hydroxide in water to prepare an alkali-activated solution having a fixed alkali concentration, water content and modulus;

[0016] S2. After the electromagnetic radiation shielding material and the neutron shielding material are evenly mixed, they are placed in a ball mill for grinding for 60 minutes, the speed is set to 400 rpm, and then passed through a 200-mesh sieve, and placed in a 105° C. oven for drying for 48 hours to obtain a fine-grained mixed radiation shielding material with a particle size of less than 75 μm;

[0017] S3, mixing the fine-grained mixed radiation shielding material obtained in S2 with the alkali excitation solution obtained in S1, and dispersing them evenly using ultrasound to obtain a radiation shielding alkali excitation solution.

[0018] S4, mixing the radiation shielding alkali excitation solution obtained in S3 with the soil material, and mixing them evenly in a cement mortar mixer to obtain a radiation-proof building material mixture;

[0019] S5. Pour the radiation-proof building material mixture obtained in S4 into a mold, place it in a closed normal pressure environment at 60° C. and cure it to a certain age to obtain a radiation-proof building material with a certain strength.

[0020] Beneficial effects:

[0021] The present invention provides a radiation-proof curing agent and building material, which achieves a breakthrough in the design of radiation-proof building material solutions using lunar in-situ resources. The characteristics of the simulated lunar soil material, such as small particle size, large specific surface area, and rich silicon-aluminum phase content, are utilized, and an alkaline environment is created by alkali excitation, which promotes the depolymerization of the active silicon-aluminum phase to form silicon-oxygen tetrahedron and aluminum-oxygen tetrahedron oligomers, and the oligomers are condensed to form amorphous polymers with a three-dimensional network space structure, so that the strength of the lunar soil solidification body is stable. By means of ultrasonic dispersion after grinding, the electromagnetic radiation shielding material and the neutron shielding material can be better dispersed in the curing material mixture with the exciter and fixed by the polymer, which helps the radiation shielding material per unit volume to absorb and scatter radiation, making the radiation shielding efficiency higher.

[0022] As one of the most abundant minerals on the moon, ilmenite itself has excellent radiation shielding capabilities. The use of lunar soil and ilmenite can greatly reduce dependence on Earth resources and reduce the cost of lunar surface construction. Barite, polyethylene and boron carbide are commonly used raw materials in the field of radiation protection materials, with stable chemical properties and easy use. Barite has a good radiation absorption effect due to the large atomic mass of barium; polyethylene contains a large amount of hydrogen, which can slow down fast neutrons; boron carbide contains a large number of boron atoms, which have a high neutron absorption cross-section and can effectively shield neutron radiation. These materials have mature application cases and can ensure the radiation protection ability of lunar soil reinforcement materials. The radiation-proof building materials described in this patent can cope with the complex radiation environment on the lunar surface, and have broad prospects for engineering applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. By referring to the drawings, the features and advantages of the present invention will be more clearly understood. The drawings are schematic and should not be understood as limiting the present invention in any way. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 The present invention is a flow chart of a method for preparing a radiation-proof building material. DETAILED DESCRIPTION

[0025] In order to make those skilled in the art better understand the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only embodiments of a part of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work should belong to the scope of protection of the present invention. If not otherwise specified, the technical means adopted in the embodiments are conventional reagents, methods and equipment well known to those skilled in the art.

[0026] The embodiment of the present invention discloses a radiation-proof curing agent, comprising the following raw materials in parts by weight: 220 to 400 parts of water, 90 to 255 parts of sodium silicate, 10 to 55 parts of sodium hydroxide, 0 to 300 parts of electromagnetic radiation shielding material, and 0 to 300 parts of neutron shielding material. It should be noted that the components of the radiation-proof curing agent of the embodiment of the present invention exist independently, or form a mixed radiation shielding alkali excitation solution (mixture).

[0027] The second aspect of the present invention further discloses a radiation-proof building material, which can be prepared by mixing a radiation-proof curing agent with a corresponding soil material. The material specifically comprises the following raw materials: 220 to 400 parts of water, 90 to 255 parts of sodium silicate, 10 to 55 parts of sodium hydroxide, 0 to 300 parts of electromagnetic radiation shielding material, 1500 to 2000 parts of soil material, and 0 to 300 parts of neutron shielding material. The particle size range of the soil material is 0.01 μm to 1 mm, the median particle size is 51 to 138 μm, and the density is 1.10 to 1.89 g / cm.

[0028] Preferably, the soil material contains 5% to 16% of alkaline oxides, and the alkaline oxides are composed of at least one of K2O, Na2O, and CaO.

[0029] Specifically, the raw materials used in the embodiments of the present invention are as follows:

[0030] The soil material is simulated lunar soil: the chemical composition is shown in Table 1, and the density is 1.51 g / cm 3 , median particle size 88μm.

[0031] Table 1 Chemical composition of simulated lunar soil (wt%)

[0032]

[0033] Sodium silicate: Powdered instant sodium silicate, modulus 2.43, SiO2 content 54.61%.

[0034] Sodium hydroxide: analytical grade powdered material, purity greater than 99%.

[0035] Ilmenite: Chemical composition is shown in Table 2, density 3.93g / cm3 .

[0036] Table 2 Chemical composition of ilmenite (wt%)

[0037]

[0038] Barite: BaSO4 mass fraction 98%, density 4.35g / cm 3 .

[0039] Polyethylene: Maximum particle size less than 60 μm, density 0.93 g / cm 3 .

[0040] Boron carbide: Maximum particle size is less than 100μm and purity is greater than 99%.

[0041] Example 1 A radiation protection building material, the raw material components, measured by weight, include 51 parts of sodium hydroxide, 102 parts of sodium silicate, 389 parts of water, 1576 parts of simulated lunar soil, 159 parts of ilmenite, 149 parts of barite, 32 parts of polyethylene, and 85 parts of boron carbide.

[0042] Example 2 A radiation protection building material, the raw material components, measured by weight, include 32 parts of sodium hydroxide, 173 parts of sodium silicate, 386 parts of water, 1576 parts of simulated lunar soil, 159 parts of ilmenite, 149 parts of barite, 32 parts of polyethylene, and 85 parts of boron carbide.

[0043] Example 3 A radiation protection building material, the raw material components, measured by weight, include 11 parts of sodium hydroxide, 247 parts of sodium silicate, 382 parts of water, 1576 parts of simulated lunar soil, 159 parts of ilmenite, 149 parts of barite, 32 parts of polyethylene, and 85 parts of boron carbide.

[0044] Example 4 A radiation protection building material, the raw material components, calculated by weight, include 32 parts of sodium hydroxide, 173 parts of sodium silicate, 386 parts of water, 1438 parts of simulated lunar soil, 290 parts of ilmenite, and 272 parts of barite.

[0045] Example 5 A radiation protection building material, the raw material components, calculated by weight, include 32 parts of sodium hydroxide, 173 parts of sodium silicate, 386 parts of water, 1704 parts of simulated lunar soil, 153 parts of ilmenite, and 143 parts of barite.

[0046] Example 6 A radiation protection building material, the raw material components, calculated by weight, include 32 parts of sodium hydroxide, 173 parts of sodium silicate, 386 parts of water, 1743 parts of simulated lunar soil, 70 parts of polyethylene, and 187 parts of boron carbide.

[0047] Example 7 A radiation protection building material, the raw material components, calculated by weight, include 32 parts of sodium hydroxide, 173 parts of sodium silicate, 386 parts of water, 1877 parts of simulated lunar soil, 34 parts of polyethylene, and 90 parts of boron carbide.

[0048] Comparative Example 1: A radiation-proof building material, wherein the raw material components, measured by weight, include 32 parts of sodium hydroxide, 173 parts of sodium silicate, 386 parts of water, and 2000 parts of simulated lunar soil.

[0049] Comparative Example 2: A radiation-proof building material, the raw material components, calculated by weight, include 32 parts of sodium hydroxide, 173 parts of sodium silicate, 386 parts of water, 1741 parts of simulated lunar soil, and 259 parts of ilmenite.

[0050] Comparative Example 3: A radiation-proof building material, the raw material components, calculated by weight, include 32 parts of sodium hydroxide, 173 parts of sodium silicate, 386 parts of water, 1712 parts of simulated lunar soil, and 288 parts of barite.

[0051] Comparative Example 4: A radiation-proof building material, the raw material components, calculated by weight, include 32 parts of sodium hydroxide, 173 parts of sodium silicate, 386 parts of water, 1931 parts of simulated lunar soil, and 69 parts of polyethylene.

[0052] Comparative Example 5: A radiation-proof building material, wherein the raw material components, calculated by weight, include 32 parts of sodium hydroxide, 173 parts of sodium silicate, 386 parts of water, 1826 parts of simulated lunar soil, and 174 parts of boron carbide.

[0053] The preparation methods of Examples 1 to 7 and Comparative Examples 1 to 5 are as follows. Figure 1 As shown:

[0054] S1. Dissolving sodium silicate and sodium hydroxide in water to prepare an alkali-activated solution having a fixed alkali concentration, water content and modulus;

[0055] S2. After the electromagnetic radiation shielding material and the neutron shielding material are evenly mixed, they are placed in a ball mill for grinding for 60 minutes, the speed is set to 400 rpm, and then passed through a 200-mesh sieve, and placed in a 105° C. oven for drying for 48 hours to obtain a fine-grained mixed radiation shielding material with a particle size of less than 75 μm;

[0056] S3, mixing the fine-grained mixed radiation shielding material obtained in S2 with the alkali excitation solution obtained in S1, and dispersing them evenly using ultrasound to obtain a radiation shielding alkali excitation solution.

[0057] S4, mixing the radiation shielding alkali excitation solution obtained in S3 with the soil material, and mixing them evenly in a cement mortar mixer to obtain a radiation-proof building material mixture;

[0058] S5. Pour the radiation-proof building material mixture obtained in S4 into a mold, place it in a closed normal pressure environment at 60° C. for curing for 7 days to obtain a radiation-proof building material with a certain strength.

[0059] Test indicators:

[0060] The specimens of each embodiment are blocks with a size of 20×20×5 cm, and the shielding effect of each specimen on gamma ray and neutron radiation is tested. The gamma ray radiation source energy used in the test is 0.662 MeV and 1.17 MeV, and the neutron source energy is 0.05 MeV and 1.5 MeV.

[0061] The linear attenuation coefficient (μ), half-value layer (H VL ) index evaluates the gamma ray shielding performance of radiation-proof building materials. μ represents the probability of radiation being absorbed when passing through a unit thickness of material, H VL It indicates the material thickness required when the ray intensity decays to half of the original intensity. The calculation method is shown in Formula 1 and Formula 2.

[0062]

[0063]

[0064] Among them, I0 is the initial intensity of gamma rays; I is the intensity of gamma rays after passing through the material; x is the thickness of the material.

[0065] Using macroscopic absorption cross section (∑R), half-value layer (H VL ) is used as an evaluation index for neutron shielding of radiation-proof building materials. ∑R represents the ability of the material to absorb neutrons, and the calculation method is shown in formula 3 and formula 4.

[0066]

[0067]

[0068] Among them, N0 is the initial dose equivalent rate of neutron rays; N is the dose equivalent rate of neutron rays passing through the material; x is the material thickness.

[0069] The radiation shielding effects of the embodiments and comparative examples are shown in Table 3.

[0070] Table 3 Radiation shielding effect of radiation-proof simulated lunar soil solidification materials

[0071]

[0072] The results of Examples 1, 2, and 3 show that the four radiation-proof materials can significantly improve the radiation-proof ability by partially combining simulated lunar soil. The radiation-proof building materials can still maintain good working performance after adding radiation-proof materials, and their density value increases with the modulus of the alkali activator, thereby improving the gamma-ray linear attenuation coefficient and neutron macroscopic absorption cross section of the material. The gamma-ray linear attenuation coefficient of Examples 4 and 5 is higher than that of Comparative Examples 2 and 3, and the half-value layer is smaller than that of the other examples, indicating that barite and ilmenite have significant shielding effects on gamma rays, and the use effect of the two materials is better than that of a single material, which is due to the high density and high absorption cross section of the two materials, and increases the probability of generating photoelectric effect and Compton effect by interacting with the gamma-ray particle flow. Polyethylene and boron carbide have unsatisfactory absorption effects on gamma rays due to their low density, and their linear attenuation coefficient is lower than that of the solidified body without shielding material (Comparative Example 1), but their absorption effect on neutrons is significant, especially for medium-energy neutrons with an energy of 0.05 MeV, which is due to the slowing down of neutrons by polyethylene and the large absorption cross section of boron carbide. The half-value layer index of Example 7 (low-doped polyethylene and boron carbide) is less than 3 cm, which is better than that of Group 6 (high-doped polyethylene and boron carbide), indicating that the dosage of boron carbide and polyethylene should not be too much. This is mainly because lightweight materials have a negative impact on the matrix density, and the combined effect of the two materials is better than that of single mixing. The radiation-proof building material of the present invention can significantly improve the radiation absorption capacity of simulated lunar soil, can be widely used in lunar surface construction, and provide assistance for radiation protection of personnel and equipment.

[0073] It should be noted that the simulated lunar soil used in the embodiments of the present invention has limited effect on the radiation protection performance of embodiments 1-7 of the present invention, but the alkaline oxides in the soil material have a clear effect on the structure of the building material. Specifically, active calcium oxide, potassium oxide, and sodium oxide will participate in the alkaline excitation reaction of the simulated lunar soil and affect the structure of the reaction products. In an alkaline solution environment, the simulated lunar soil dissolves, Si, Ca, Al, K, and Na are dissolved, and aluminosilicate gel and Ca are formed. 2+ , K + 、Na + .Ca 2+ It can be combined with silicon and aluminum dissolution to form CSH / CASH amorphous structure. The monosilicate and aluminate dissolved in the low calcium system can undergo polymerization to form a three-dimensional network structure of aluminosilicate, which contains silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons, which are connected by shared oxygen ions. In the process of forming a highly polymerized three-dimensional structure, charge imbalance is generated due to ion substitution. Alkali metal cations K+ and Na+ are included in the structure to balance the charge. + Than Na + It has a smaller ionic radius, so it is easier to enter the aluminum-oxygen tetrahedron to balance the charge, so the free K in the system +It can promote the occurrence of mineral polymerization reaction with hydrated aluminosilicate, and finally polymerize to form potassium A type zeolite.

[0074] Therefore, the soil material in the embodiment of the present invention preferably contains 5% to 16% of alkaline oxides, and the alkaline oxides are composed of at least one of K2O, Na2O, and CaO.

[0075] Optionally, the alkaline oxide in the embodiment of the present invention is composed of K2O, Na2O, and CaO in a weight ratio of (2-3): (6-7): (6-8).

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the specification of this application, the technicians can still modify or replace the specific implementation mode of the present invention with equivalents, but these modifications or changes do not deviate from the scope of protection of the pending claims of the present application.

Claims

1. A radiation-proof curing agent, characterized in that: The radiation-proof curing agent comprises the following raw materials: 220-400 parts of water, 90-255 parts of sodium silicate, 10-55 parts of sodium hydroxide, 0-300 parts of electromagnetic radiation shielding material, and 0-300 parts of neutron shielding material; The electromagnetic radiation shielding material and the neutron shielding material are not 0; The electromagnetic radiation shielding material is a composite material formed by mixing ilmenite and barite in a weight ratio of (10-20): (10-20); The neutron shielding material is a composite material formed by mixing polyethylene powder and boron carbide in a weight ratio of (3-4): (8-9).

2. A radiation-proof curing agent according to claim 1, characterized in that: The SiO2 content in the sodium silicate is 52-56%.

3. A radiation-proof curing agent according to claim 2, characterized in that: The specific surface area of ​​sodium silicate is 150 m 2 / g.

4. The radiation-proof curing agent according to claim 1, characterized in that: The iron content of the ilmenite is not less than 40%; the mass content of BaSO4 in the barite is not less than 98%.

5. The radiation-proof curing agent according to claim 1, characterized in that: The polyethylene powder has a particle size of 50 to 70 μm and a density higher than 0.92 g / cm 3 ; The boron carbide particle size is less than 175μm and the boron content is higher than 70%.

6. A radiation-proof building material, characterized in that: The radiation-proof building material comprises the following raw materials: 220-400 parts of water, 90-255 parts of sodium silicate, 10-55 parts of sodium hydroxide, 0-300 parts of electromagnetic radiation shielding material, 1500-2000 parts of soil material, and 0-300 parts of neutron shielding material. The particle size of the soil material ranges from 0.01 μm to 1 mm, the median particle size is 51-138 μm, and the density is 1.10 to 1.89 g / cm; The electromagnetic radiation shielding material and the neutron shielding material are not 0; The electromagnetic radiation shielding material is a composite material formed by mixing ilmenite and barite in a weight ratio of (10-20): (10-20); The neutron shielding material is a composite material formed by mixing polyethylene powder and boron carbide in a weight ratio of (3-4): (8-9).

7. A radiation-proof building material according to claim 6, characterized in that: The soil material contains 5% to 16% of alkaline oxides, and the alkaline oxides are composed of at least one of K2O, Na2O and CaO.

8. The radiation-proof building material according to claim 6, characterized in that: The preparation method of the radiation-proof building material comprises the following steps: S1. Dissolving sodium silicate and sodium hydroxide in water to prepare an alkali-activated solution having a fixed alkali concentration, water content and modulus; S2. After the electromagnetic radiation shielding material and the neutron shielding material are evenly mixed, they are placed in a ball mill for grinding for 60 min, the speed is set to 400 rpm, and then passed through a 200-mesh sieve, and placed in an oven at 105°C for drying for 48 h to obtain a fine-grained mixed radiation shielding material with a particle size of less than 75 μm; S3, mixing the fine-grained mixed radiation shielding material obtained in S2 with the alkali excitation solution obtained in S1, and dispersing them evenly using ultrasound to obtain a radiation shielding alkali excitation solution; S4, mixing the radiation shielding alkali excitation solution obtained in S3 with the soil material, and mixing them evenly in a cement mortar mixer to obtain a radiation-proof building material mixture; S5. Pour the radiation-proof building material mixture obtained in S4 into a mold, place it in a closed normal pressure environment at 60° C. and cure it to a certain age to obtain a radiation-proof building material with a certain strength.

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