High-activity beta-calcium silicate for cultural relic protection and preparation and application thereof

Abstract

The present application relates to the technical field of cultural relic protection materials, and particularly relates to a high-activity beta-Ca2SiO4 for cultural relic protection and preparation and application thereof. On the basis of a traditional solid-phase synthesis process, a new boron-containing crystal form stabilizer is used to obtain high-activity beta-Ca2SiO4 through high-temperature solid-phase synthesis, or high-activity beta-Ca2SiO4 is obtained through high-temperature solid-phase synthesis and then airflow milling. The boron-containing crystal form stabilizer with low water solubility is selected, which on the one hand effectively reduces the volatilization of boron during high-temperature solid-phase reaction, and on the other hand effectively avoids the uneven phenomena such as crystallization and stratification after drying caused by the use of water-soluble crystal form stabilizers such as boric acid and sodium borate during wet processing. In addition, the calcium and calcium-silicon elements contained in the introduced boron-containing crystal form stabilizer are necessary components for beta-Ca2SiO4 synthesis, and the high-activity beta-Ca2SiO4 prepared by using the present application has a lower soluble salt content.

Description

Technical Field

[0001] This invention relates to the field of cultural relic protection materials technology, and in particular to a highly active β-Ca2SiO4 for cultural relic protection and its preparation and application. Background Technology

[0002] Brick, tile, and stone artifacts are cultural relics processed from man-made silicate bricks and tiles and natural stone. Examples include building bricks and tiles, pictorial bricks and stones, grottoes, cliff carvings, stone sculptures, stone inscriptions, steles, sutra pillars, and stone tools. They are diverse in type, subject matter, and style. These artifacts are numerous and widely distributed. Closely related to human activities at the time, these brick, tile, and stone artifacts possess significant historical, technological, and artistic value, and are rare, scarce, and non-renewable cultural resources.

[0003] Brick, tile, and stone cultural relics often suffer from various types of damage due to natural environment, forces, earthquakes, and human activities. Among these, fractures, defects, and surface weathering severely affect the safety of the relics themselves, leading to irreversible damage to their value. Immovable stone cultural relics are also commonly affected by water and salt. The presence of water can cause secondary damage, including rock structure destruction, weathering, and the spread of microorganisms and vegetation. The treatment of these damages typically involves measures such as crack grouting, surface sealing, adhesive reinforcement, and infiltration reinforcement. Repairing damaged areas is sometimes also necessary.

[0004] Materials used for bonding and reinforcing bricks, tiles, and stone artifacts typically include organic, inorganic, and organic-inorganic composite materials.

[0005] Organic reinforcement materials have been used for the protection of stone cultural relics for over sixty years. Due to their good adhesion and flexibility, as well as their excellent tensile stress resistance, they have been widely used in the protection of brick and stone cultural relics. Currently, commonly used organic reinforcement materials include epoxy resin, acrylic resin, and silicone materials. Among them, epoxy resin is a widely used reinforcement material. It has advantages such as high bonding strength, low curing temperature, low curing shrinkage, corrosion resistance, and convenient processing. In the 1970s, cultural relic conservationists used it in the protection project of Yungang Grottoes and achieved good results (Li Zhiguo, Fifty Years of Scientific and Technological Protection Research of Yungang Grottoes [J]. Cultural Relics World, 2004(5):3-7). However, long-term research has found that the effective lifespan of organic reinforcement materials in the field often fails to meet the requirements for cultural relic protection. Byproducts and residues after failure may also damage cultural relics and are difficult to remove. The contradiction between the hydrophilicity of the stone itself and the hydrophobicity of the organic protective film (Liu Qiang, Zhang Bingjian, Long Mei, Study on the side effects of hydrophobic chemical protection of stone cultural relics[J]. Cultural Relics Protection and Archaeological Science, 2006, 18(2):1-6) also makes the surface layer of the stone susceptible to stress damage and salt crystallization damage (Baglioni P, Giorgi R. Soft and hard nanomaterials for restoration and conservation of cultural heritage[J]. Soft Matter, 2006, 2(4):293-303). Therefore, considering the long-term effect, organic materials are difficult to meet the requirements for the protection of stone cultural relics.

[0006] Combining or hybridizing inorganic and organic materials to address the shortcomings of each material has attracted widespread attention in recent decades (Kickelbick G. Concepts for the incorporation of inorganic building blocks into organic polymers on a nanoscale[J]. Prog Polym Sci,2003,28(1):83-114).Many materials, such as organosilicon and its modified materials (Huang Y, Liu W, Zhou X. Silicone / silica nanocomposites as culture-stone protective materials[J]. J Appl Polym Sci, 2012, 125(SI): 282-291), acrylic acid and its modified materials (Sabatini V, Cattò C, Silvester GD, et al. Protective features, durability and biodegration study of acrylic and methacrylic fluorinated polymer coatings for marble protection[J], Prog OrgCoat, 2018, 114(2018): 47-57), epoxy resin and its modified materials (Pocius AV. Adhesion and Adhesives Technology[M]. Hanser, 2012), fluorosilicone composite materials (Licchelli M, Marzolla SJ, Poggi A, et al. Crosslinked fluorinated polyurethanes for the protection of stone surfaces from graffiti[J]. J Cult Herit, 2011, 12(1):34-43), and nano-inorganic modified composite materials (Tian SP, Liu SJ, Gao F, et al. Preparation and Assessment of Superhydrophobic Organic-Inorganic Hybrid Coatings for Conservation of Yongang Grottoes[J]. Materials Research Society Symposium Proceedings. 2011, 1319 http: / / journals.Cambridge.org / abstract-s1946427411007366) have been gradually introduced into the weathering protection of sandstone cultural relics, providing more options and opportunities for cultural relic protection. However, the long-term impact of the presence of organic components on protective materials has not yet been well assessed.

[0007] Inorganic reinforcing materials were among the earliest materials used in stone preservation. The reinforcing mechanism of inorganic reinforcing materials is to utilize the coagulation of inorganic substances in the pores of bricks and stones or to chemically react with the cementitious substances in the stone to form new substances, thereby reducing the porosity of the stone and increasing its structural strength, thus playing a certain role in reinforcing and protecting brick and stone cultural relics. Inorganic reinforcing materials used at home and abroad include natural hydraulic lime (Zhang B, Liu P, Qi N, et al. Regulation of oxidation degree for graphene oxide on hydration process and engineering properties of natural hydraulic lime pastes for grout strengthening of stonecultural relics[J]. Construction & Building Materials, 2023(Dec.1):407), lime water, barium hydroxide, and alkaline earth silicates, etc. (Han Dongmei, Guo Guangsheng, Shi Zhimin, et al. Application of chemical reinforcing materials in the preservation of stone cultural relics[J]. Cultural Relics Protection and Archaeological Science, 1999(2):41-44). As early as the 1970s, the British used lime water to reinforce the sculptures of Wells Cathedrals (Marsh P. Breathing new life into statues of Wells[J]. New Scientist, 1977, 76(1083): 754-756). The Institute of Cultural Relics Conservation of Dunhuang Academy in my country has developed a new inorganic reinforcement material for stone cultural relics and earthen sites—PS (high modulus potassium silicate) material (Li Zuixiong, Stability and strength problems of PS reinforcement of earthen and stone cultural relics[J]. Dunhuang Research, 1996(3): 96-111). This material is mainly composed of potassium silicate aqueous solution with a modulus of 3.8 to 4.0, curing agent, crosslinking agent and dispersant. It penetrates into the interior of weathered sandstone and can undergo complex physical and chemical reactions with carbonates, clay minerals and other components in the sandstone to form a fibrous inorganic composite containing a Si-O skeleton, thereby improving the connection strength between particles inside the sandstone. Inorganic materials, being of the same material composition as brick and stone artifacts, possess good anti-aging properties. However, their permeability and adhesion are poor. Reinforcing materials are mainly found on the surface of stone artifacts, easily forming a hard shell that affects the stone's breathability. This is a bottleneck restricting the application of such materials in the preservation of stone artifacts. In addition, silicate cement has also been widely used in artifact restoration.

[0008] While ordinary silicate cement can provide high bond strength, its high soluble salt content has been shown to cause secondary damage to cultural relics. Furthermore, the high exothermic hydration of silicate cement may also damage brick and stone artifacts.

[0009] In this regard, the inventors analyzed the main components (C3S, C2S, C3A, C4AF) in ordinary silicate cement clinker. They found that β-Ca2SiO4 (C2S) has advantages such as low heat of hydration, high strength of the aggregate, and excellent durability. They innovatively proposed using this material in the protection of brick and stone cultural relics, and have already achieved excellent results.

[0010] However, Ca2SiO4 contains α and α′. H α′ L It exhibits multiple crystal forms, including α, β, and γ, among which the γ form lacks hydration activity. Avoiding the formation of γ-Ca₂SiO₄ is the key and challenging aspect of preparing this cementitious material. Meanwhile, the high-temperature forms (α, α′...)... H α′ L Since Ca2SiO4 exists at a high temperature, the preparation of β-Ca2SiO4 has become a hot topic for this type of cementitious material.

[0011] Currently, β-Ca₂SiO₄ is mainly prepared via the sol-gel method and solid-phase synthesis. The sol-gel method, with its lower synthesis temperature, smaller particle size, and better uniformity, results in higher activity. However, its preparation process is complex, raw materials are expensive, and the organic solvents used contain toxic substances, posing significant safety risks and leading to high production costs. This method is not economically viable for large-scale industrial production, and materials prepared using this method are primarily used in scientific research and biomedicine. In high-temperature solid-phase synthesis, special processing techniques are generally required to prevent the formation of the γ-phase in the final product. These techniques include rapid cooling or the addition of crystal stabilizers during synthesis. Adding crystal stabilizers combined with rapid cooling is a reliable method for stabilizing the preparation of β-Ca₂SiO₄. Existing research indicates that ions with stabilizing effects on β-Ca₂SiO₄ mainly include K₂. + Na + ,Ba 2+ B 3+ Al 3+ ,Mn 4+ ,P 5+ and S 6+ et al. (G.-C. Lai, T. Nojiri, K. Nakano, Studies of the stability of β-Ca2SiO4 doped by minor ions, Cem. Concr. Res. 22 (1992) 743-754).

[0012] Among them B 3+ It is a highly effective β-Ca2SiO4 crystal form stabilizer. It is introduced into the B crystal structure through borax and boric acid. 3+ As a crystal stabilizer, borax can effectively reduce calcination temperature, offering significant advantages. However, as a material for cultural relic preservation, it requires low soluble salt content, and the sodium ions in borax make this additive unsuitable. When boric acid is used as a crystal stabilizer, its volatilization at high temperatures sometimes causes it to lose its intended effect, or requires excessive addition to achieve the desired crystal stabilization. Furthermore, both borax and boric acid are readily soluble in water. When using wet grinding to process raw powder, there is a drawback: component segregation during drying, increasing the difficulty of subsequent homogenization. Existing research indicates that β-Ca2SiO4 typically has low hydration activity, resulting in lower initial strength of the prepared specimens, with strength development requiring a lengthy process. Therefore, providing a technical solution that addresses the aforementioned problems is crucial. Summary of the Invention

[0013] To address the aforementioned problems, the purpose of this invention is to provide a highly active β-Ca2SiO4 for cultural relic protection, as well as its preparation and application.

[0014] For the introduction of B via boric acid 3+ When used as a crystal stabilizer, it suffers from serious problems such as high-temperature volatilization. This invention, based on traditional solid-phase synthesis processes, proposes the use of a novel boron-containing crystal stabilizer to obtain highly active β-Ca₂SiO₄ through high-temperature solid-phase synthesis, or through high-temperature solid-phase synthesis followed by air jet milling. This invention selects a boron-containing crystal stabilizer with low water solubility, which effectively reduces boron volatilization during high-temperature solid-phase reactions. Furthermore, during wet processing, it effectively avoids uneven phenomena such as crystallization and stratification after drying caused by the use of water-soluble crystal stabilizers such as boric acid and sodium borate. In addition, the calcium and calcium-silicon elements contained in the introduced boron-containing crystal stabilizer are essential components in the synthesis of β-Ca₂SiO₄, resulting in a lower soluble salt content in the highly active β-Ca₂SiO₄ prepared using this invention.

[0015] The objective of this invention can be achieved through the following technical solutions:

[0016] The first objective of this invention is to provide a highly active β-Ca2SiO4 for the preservation of cultural relics, which is prepared by solid-phase synthesis of calcium carbonate, silicon dioxide and a boron-containing crystal stabilizer.

[0017] The boron-containing crystal stabilizer is selected from one or more of boron-calcium compounds or calcium-boron-silicon compounds.

[0018] In one embodiment of the present invention, the boron-calcium compound is selected from calcium metaborate (CaB2O4·6H2O), calcium borate, or calcium staborite (Ca2B6O). 11 One or more of the following: ·5H2O;

[0019] The calcium-boron-silicon compound is selected from one or more of calcium borosilicate (BCaSiH5O7) and calcium borosilicate (CaBSiO4(OH)).

[0020] In one embodiment of the present invention, the calcium borate is one or a combination of the following: diborates (CaO·B2O3·nH2O), ditetraborates (CaO·2B2O3·nH2O), tetraborates (2CaO·3B2O3·nH2O), and dihexaborates (CaO·3B2O3·nH2O) of the general formula xCaO·yB2O3·nH2O.

[0021] The second objective of this invention is to provide a method for preparing highly active β-Ca2SiO4 for cultural relic preservation, wherein the highly active β-Ca2SiO4 for cultural relic preservation is selected from either β-Ca2SiO4 that has not been pulverized by an air jet mill or β-Ca2SiO4 that has been pulverized by an air jet mill.

[0022] The preparation of highly active β-Ca2SiO4 for cultural relic preservation specifically includes the following steps:

[0023] (S1) After mixing calcium carbonate, silicon dioxide and boron-containing crystal stabilizer, the mixture is ball-milled to obtain raw feed.

[0024] (S2) The raw materials prepared in step (S1) are calcined and then rapidly cooled to obtain β-Ca2SiO4 that has not been pulverized by an air jet mill.

[0025] Alternatively, the raw materials prepared in step (S1) can be calcined, rapidly cooled, and then pulverized by an air jet mill to obtain β-Ca2SiO4 pulverized by an air jet mill.

[0026] In one embodiment of the present invention, in step (S1), the number of calcium atoms in calcium carbonate is twice the number of silicon atoms in silicon dioxide; the number of boron atoms in the boron-containing crystal stabilizer is 1 to 10% of the number of silicon atoms in silicon dioxide (preferably, the number of boron atoms in the boron-containing crystal stabilizer is 2 to 6% of the number of silicon atoms in silicon dioxide).

[0027] In one embodiment of the present invention, in step (S1), the ball milling process is selected from either dry ball milling or wet ball milling.

[0028] In one embodiment of the present invention, the dispersant is selected from one or more of gum arabic, gelatin, or organic polymer water-reducing agents; wherein, the addition of the dispersant can effectively reduce the moisture content in the slurry and save energy consumption required for slurry drying; the organic material can be completely decomposed at high temperature without causing harmful ion residues.

[0029] In one embodiment of the present invention, during the dry ball milling process, the rotation speed is 300-350 r / min and the time is 40-60 min;

[0030] During the wet ball milling process, a dispersant is added at a rate of 0.8% to 1.2% of the combined mass of calcium carbonate, silica, and boron-containing crystal stabilizer. The rotation speed is 330 to 360 r / min, and the time is 20 to 28 h. After the wet ball milling is completed, the mixture is dried and pulverized.

[0031] In one embodiment of the present invention, when the ball milling is wet ball milling, the boron-containing crystal stabilizer is a boron-containing crystal stabilizer with low water solubility;

[0032] Preferably, the boron-containing crystal stabilizer is CaB2O4·2H2O;

[0033] Preferably, the boron-containing crystal stabilizer is Ca2B6O. 11 ·5H2O;

[0034] Preferably, the boron-containing crystal stabilizer is calcium borate;

[0035] Preferably, the boron-containing crystal stabilizer is Ca2B6O. 11 A composition of ·5H2O, CaB2O4·2H2O and calcium borate;

[0036] Preferably, the boron-containing crystal stabilizer is a calcium-boron-silicon compound with low water solubility.

[0037] In one embodiment of the present invention, in step (S2), the calcination process is carried out at a temperature of 800-1500°C for 1-24 hours.

[0038] In one embodiment of the present invention, the calcination temperature and calcination time are determined based on the particle size of the selected raw materials, the fineness of the powder after processing the raw materials, and the amount of boron-containing crystal stabilizer, and are also determined based on the properties of the resulting clinker.

[0039] In one embodiment of the present invention, in step (S2), during the air jet mill pulverization process (particles are pulverized by high-speed collision and further activated), the pressure of the feeding nozzle is 0.3-0.4 MPa, and the pressure of the pulverizing nozzle is 0.6 MPa;

[0040] The particle size D of β-Ca2SiO4 pulverized by air jet mill 90 Less than 20μm.

[0041] In one embodiment of the present invention, the particle size of the highly active β-Ca2SiO4 used for cultural relic protection is determined by parameters such as the working pressure and feeding speed of the air jet mill; it can be adjusted according to actual needs.

[0042] Preferably, the particle size D of the highly active β-Ca2SiO4 used for cultural relic protection is... 90 Less than 15μm;

[0043] More preferably, the particle size D of the highly active β-Ca2SiO4 for cultural relic preservation is... 90 Less than 10μm.

[0044] The third objective of this invention is to provide an application of highly active β-Ca2SiO4 for cultural relic preservation in the preparation of cultural relic preservation products.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) The present invention selects boron-calcium compounds, calcium-boron-silicon compounds or combinations thereof with low water solubility, which effectively reduces boron volatilization during high-temperature solid-phase reactions; during wet processing, it effectively avoids uneven phenomena such as crystallization and layering after drying caused by the use of water-soluble crystal stabilizers such as boric acid and sodium borate.

[0047] (2) The calcium and calcium-silicon elements contained in the boron-containing crystal stabilizer introduced in this invention are essential components in the synthesis of β-Ca2SiO4. The highly active β-Ca2SiO4 prepared using this invention has a lower soluble salt content and a better doping effect of the crystal stabilizer. Attached Figure Description

[0048] Figure 1 The image shows the X-ray diffraction pattern of the clinker prepared in Example 1 without air jet milling.

[0049] Figure 2 The clinker prepared in Example 1 without air jet milling ( Figure 2 (a)) and clinker pulverized by air jet milling ( Figure 2 (b) Particle size distribution diagram.

[0050] Figure 3 The compressive strength of clinker prepared by air jet milling in Example 1 at different ages.

[0051] Figure 4 This is a comparison chart of the compressive strength of clinker prepared in Example 1 that was not pulverized by an air jet mill and that was pulverized by an air jet mill.

[0052] Figure 5 The image shows the X-ray diffraction pattern of the clinker prepared in Comparative Example 1 without air jet milling.

[0053] Figure 6 The images show the original state of the surface cracks on the North Hill of Dazu Rock Carvings and the appearance of the surface after being sealed with clinker (β-Ca2SiO4) prepared by air jet milling as described in Example 1. Detailed Implementation

[0054] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0055] In the following examples, calcium carbonate (AR) and silicon dioxide (AR) were purchased from Sinopharm Chemical Reagent Co., Ltd.; calcium borosilicate was obtained from the Tieshan iron ore deposit in Daye, Hubei Province, and was a relatively pure natural calcium borosilicate (CaBSiO4(OH)); calcium borosilicate was purchased from Shanghai Hongtu Trading Co., Ltd. (BCaSiH5O7); calcium metaborate was purchased from Shaanxi Didu Pharmaceutical Chemical Co., Ltd.; calcium stearate was purchased from Wuhan Xingzhongcheng Technology Co., Ltd.; tetravalent hexaborate was purchased from Chengdu Yuanmingxu Chemical Products Co., Ltd.; and divalent diborate, divalent tetraborate, and divalent hexaborate were all purchased from Jinan Yuansu Chemical Co., Ltd.

[0056] Unless otherwise specified, all reagents used are commercially available, and all detection methods and techniques used are conventional in this field.

[0057] It should be noted that boron-calcium compounds and calcium-boron-silicon compounds have different trade names, and the water content in their formulas is not always a fixed value. Also, these two types of compounds, whether artificial or synthetic, may have different compositions. However, extensive experiments have shown that these raw materials have similar effects when used as boron-containing crystal stabilizers.

[0058] Example 1: Calcium borosilicate as a boron-containing crystal stabilizer

[0059] This embodiment provides a method for preparing highly active β-Ca2SiO4 (β-Ca2SiO4 pulverized by air jet milling) for cultural relic preservation, including the following steps:

[0060] (S1) Weigh 196g of calcium carbonate, 57.6g of silicon dioxide, and 6.4g of calcium borosilicate (in this embodiment, the atomic ratio of boron atoms to silicon is 4%), add them to a 1L ball mill jar, and add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the batch;

[0061] (S2) The raw material of the batch prepared in step (S1) is put into a corundum crucible, heated from room temperature to 1450°C within 5 hours and kept at that temperature for 4 hours. After being taken out, it is cooled by blowing air with an electric fan. After cooling, the clinker that has not been pulverized by the air jet mill is obtained.

[0062] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.3 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0063] In this embodiment, the crystal structure of clinker without air jet milling and clinker after air jet milling were tested using X-ray diffraction, and the particle size distribution of the powder was tested using a laser particle size analyzer. The powder crystal diffraction patterns are shown below. Figure 1 As shown ( Figure 1 In this example, "β-C2S" represents the β-Ca2SiO4 phase. The results show that the synthesized clinker without air jet milling is pure β-Ca2SiO4 phase. That is, in this embodiment, the clinker without air jet milling is β-Ca2SiO4 without air jet milling, and the clinker after air jet milling is β-Ca2SiO4 after air jet milling. The particle size distributions of the clinker without air jet milling and the clinker after air jet milling are as follows: Figure 2 As shown, the particle size distribution of clinker that has not been milled by air jet mill is as follows: Figure 2 As shown in (a), D 90 =52.85μm; the particle size distribution of clinker pulverized by air jet mill is as follows Figure 2 As shown in (b), D 90 =16.84μm.

[0064] The clinker prepared in this embodiment without air jet milling and the clinker after air jet milling were uniformly mixed with deionized water at a water-cement ratio (w / c) of 0.4 to obtain slurries. The resulting slurries were then poured into 4cm*4cm*4cm molds at room temperature for curing. After 24 hours, the samples were removed from the molds and cured for 1, 3, 7, and 28 days at 20±1℃ and 90±1% relative humidity, respectively. The compressive strength of the high-activity β-Ca2SiO4 powder samples at different curing ages was as follows: Figure 3 The diagram shows a comparison of the compressive strength of clinker that has not been milled by an air jet mill and that has been milled by an air jet mill. Figure 4 As shown.

[0065] Example 2: Calcium borosilicate as a boron-containing crystal stabilizer

[0066] This embodiment provides a method for preparing highly active β-Ca2SiO4 for cultural relic preservation, including the following steps:

[0067] (S1) Weigh 198g of calcium carbonate, 58.8g of silicon dioxide, and 3.92g of calcium borosilicate (in this example, the atomic ratio of boron atoms to silicon is 2%), add them to a 1L ball mill jar, add 200mL of water (add 1% of the mass of the raw material as a dispersant gelatin); after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material;

[0068] (S2) The raw material of the batch prepared in step (S1) is put into a corundum crucible, heated from room temperature to 1450°C within 5 hours and kept at that temperature for 4 hours. After being taken out, it is cooled by blowing air with an electric fan. After cooling, the clinker that has not been pulverized by the air jet mill is obtained.

[0069] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.35 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0070] X-ray diffraction analysis showed that the prepared clinker without air jet milling was pure β-Ca2SiO4. The particle size distribution (D) of the clinker after air jet milling was measured using a laser particle size analyzer. 90 =14.84μm.

[0071] The clinker prepared in this embodiment without air jet milling and the clinker prepared by air jet milling were mixed with deionized water at a water-cement ratio (w / c) of 0.4 to obtain a slurry. The obtained slurry was poured into a 4cm*4cm*4cm mold at room temperature for curing. After 24 hours, the sample was removed from the mold and cured for 1, 3, 7 and 28 days at 20±1℃ and 90±1% relative humidity, respectively. The compressive strength at each age was similar to that in Example 1.

[0072] Example 3: A mixture of calcium borosilicate and calcium borosilicate as a boron-containing crystal stabilizer

[0073] This embodiment provides a method for preparing highly active β-Ca2SiO4 for cultural relic preservation, including the following steps:

[0074] (S1) Weigh 194g of calcium carbonate, 52.8g of silicon dioxide, 4.8g of calcium borosilicate and 5.88g of calcium borosilicate (in this example, the atomic ratio of boron atoms to silicon is 6%), add them to a 1L ball mill jar, add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the batch;

[0075] (S2) The raw material of the batch prepared in step (S1) is put into a corundum crucible, heated from room temperature to 1450°C within 5 hours and kept at that temperature for 4 hours. After being taken out, it is cooled by blowing air with an electric fan. After cooling, the clinker that has not been pulverized by the air jet mill is obtained.

[0076] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.4 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0077] X-ray diffraction analysis showed that the prepared clinker without air jet milling was pure β-Ca2SiO4, while the particle size of the clinker after air jet milling was similar to that in Example 1.

[0078] The clinker prepared in this embodiment without air jet milling and the clinker prepared by air jet milling were mixed with deionized water at a water-cement ratio (w / c) of 0.4 to obtain a slurry. The obtained slurry was poured into a 4cm*4cm*4cm mold at room temperature for curing. After 24 hours, the sample was removed from the mold and cured for 1, 3, 7 and 28 days at 20±1℃ and 90±1% relative humidity, respectively. The compressive strength at each age was similar to that in Example 1.

[0079] Example 4: Calcium metaborate as a boron-containing crystal stabilizer

[0080] This embodiment provides a method for preparing highly active β-Ca2SiO4 for cultural relic preservation, including the following steps:

[0081] (S1) Weigh 197g of calcium carbonate, 56.4g of silicon dioxide, and 7.01g of calcium metaborate (in this example, the atomic ratio of boron atoms to silicon is 6%), add them to a 1L ball mill jar, and add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the compound;

[0082] (S2) The raw material of the batch prepared in step (S1) is put into a corundum crucible, heated from room temperature to 1450°C within 5 hours and kept at that temperature for 4 hours. After being taken out, it is cooled by blowing air with an electric fan. After cooling, the clinker that has not been pulverized by the air jet mill is obtained.

[0083] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.3 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0084] X-ray diffraction analysis showed that the prepared clinker without air jet milling was pure β-Ca2SiO4, while the particle size of the clinker after air jet milling was similar to that in Example 1.

[0085] The clinker prepared in this embodiment without air jet milling and the clinker prepared by air jet milling were mixed with deionized water at a water-cement ratio (w / c) of 0.4 to obtain a slurry. The obtained slurry was poured into a 4cm*4cm*4cm mold at room temperature for curing. After 24 hours, the sample was removed from the mold and cured for 1, 3, 7 and 28 days at 20±1℃ and 90±1% relative humidity, respectively. The compressive strength at each age was similar to that in Example 1.

[0086] Example 5: Calcium stobolarate as a boron-containing crystal stabilizer

[0087] This embodiment provides a method for preparing highly active β-Ca2SiO4 for cultural relic preservation, including the following steps:

[0088] (S1) Weigh 197g of calcium carbonate, 56.4g of silicon dioxide, and 4.11g of calcium staborate (in this example, the atomic ratio of boron atoms to silicon is 6%), add them to a 1L ball mill jar, and add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the batch;

[0089] (S2) The raw material of the batch prepared in step (S1) is put into a corundum crucible, heated from room temperature to 1450°C within 5 hours and kept at that temperature for 4 hours. After being taken out, it is cooled by blowing air with an electric fan. After cooling, the clinker that has not been pulverized by the air jet mill is obtained.

[0090] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.4 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0091] X-ray diffraction analysis showed that the prepared clinker without air jet milling was pure β-Ca2SiO4, while the particle size of the clinker after air jet milling was similar to that in Example 1.

[0092] The clinker prepared in this embodiment without air jet milling and the clinker prepared by air jet milling were mixed with deionized water at a water-cement ratio (w / c) of 0.4 to obtain a slurry. The obtained slurry was poured into a 4cm*4cm*4cm mold at room temperature for curing. After 24 hours, the sample was removed from the mold and cured for 1, 3, 7 and 28 days at 20±1℃ and 90±1% relative humidity, respectively. The compressive strength at each age was similar to that in Example 1.

[0093] Example 6: A mixture of calcium metaborate and calcium staborate as a boron-containing crystal stabilizer

[0094] This embodiment provides a method for preparing highly active β-Ca2SiO4 for cultural relic preservation, including the following steps:

[0095] (S1) Weigh 197g of calcium carbonate, 55.2g of silicon dioxide, 2.34g of calcium metaborate and 4.11g of calcium stabort (in this example, the atomic ratio of boron atoms to silicon is 8%), add them to a 1L ball mill jar, add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the compound;

[0096] (S2) The raw material of the batch prepared in step (S1) is put into a corundum crucible, heated from room temperature to 1450°C within 5 hours and kept at that temperature for 4 hours. After being taken out, it is cooled by blowing air with an electric fan. After cooling, the clinker that has not been pulverized by the air jet mill is obtained.

[0097] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.35 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0098] X-ray diffraction analysis showed that the prepared clinker without air jet milling was pure β-Ca2SiO4, while the particle size of the clinker after air jet milling was similar to that in Example 1.

[0099] The clinker prepared in this embodiment without air jet milling and the clinker prepared by air jet milling were mixed with deionized water at a water-cement ratio (w / c) of 0.4 to obtain a slurry. The obtained slurry was poured into a 4cm*4cm*4cm mold at room temperature for curing. After 24 hours, the sample was removed from the mold and cured for 1, 3, 7 and 28 days at 20±1℃ and 90±1% relative humidity, respectively. The compressive strength at each age was similar to that in Example 1.

[0100] Example 7: Tetravalent hexaborate as a boron-containing crystal stabilizer

[0101] This embodiment provides a method for preparing highly active β-Ca2SiO4 for cultural relic preservation, including the following steps:

[0102] (S1) Weigh 198g of calcium carbonate, 56.4g of silicon dioxide, and 4.29g of tetravalent hexaborate (in this example, the atomic ratio of boron atoms to silicon is 6%), add them to a 1L ball mill jar, and add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the compound;

[0103] (S2) The raw material of the batch prepared in step (S1) is put into a corundum crucible, heated from room temperature to 1450°C within 5 hours and kept at that temperature for 4 hours. After being taken out, it is cooled by blowing air with an electric fan. After cooling, the clinker that has not been pulverized by the air jet mill is obtained.

[0104] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.3 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0105] X-ray diffraction analysis showed that the prepared clinker without air jet milling was pure β-Ca2SiO4, while the particle size of the clinker after air jet milling was similar to that in Example 1.

[0106] The clinker prepared in this embodiment without air jet milling and the clinker prepared by air jet milling were mixed with deionized water at a water-cement ratio (w / c) of 0.4 to obtain a slurry. The obtained slurry was poured into a 4cm*4cm*4cm mold at room temperature for curing. After 24 hours, the sample was removed from the mold and cured for 1, 3, 7 and 28 days at 20±1℃ and 90±1% relative humidity, respectively. The compressive strength at each age was similar to that in Example 1.

[0107] Example 8: A mixture of diborates and tetraborates as a boron-containing crystal stabilizer

[0108] This embodiment provides a method for preparing highly active β-Ca2SiO4 for cultural relic preservation, including the following steps:

[0109] (S1) Weigh 198.5g of calcium carbonate, 57g of silicon dioxide, 0.9g of diborate and 2.49g of tetraborate (in this example, the atomic ratio of boron atoms to silicon is 5%), add them to a 1L ball mill jar, add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the compound;

[0110] (S2) The raw material of the batch prepared in step (S1) is put into a corundum crucible, heated from room temperature to 1450°C within 5 hours and kept at that temperature for 4 hours. After being taken out, it is cooled by blowing air with an electric fan. After cooling, the clinker that has not been pulverized by the air jet mill is obtained.

[0111] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.35 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0112] X-ray diffraction analysis showed that the prepared clinker without air jet milling was pure β-Ca2SiO4, while the particle size of the clinker after air jet milling was similar to that in Example 1.

[0113] The clinker prepared in this embodiment without air jet milling and the clinker prepared by air jet milling were mixed with deionized water at a water-cement ratio (w / c) of 0.4 to obtain a slurry. The obtained slurry was poured into a 4cm*4cm*4cm mold at room temperature for curing. After 24 hours, the sample was removed from the mold and cured for 1, 3, 7 and 28 days at 20±1℃ and 90±1% relative humidity, respectively. The compressive strength at each age was similar to that in Example 1.

[0114] Example 9: A mixture of calcium borosilicate, calcium metaborate, and dihexaborate as a boron-containing crystal stabilizer. This example provides a method for preparing highly active β-Ca2SiO4 for cultural relic preservation, comprising the following steps:

[0115] (S1) Weigh 195.5g of calcium carbonate, 54.6g of silicon dioxide, 3.2g of calcium borosilicate, 2.34g of calcium metaborate and 1.60g of dihexaborate (in this example, the atomic ratio of boron atoms to silicon is 7%), add them to a 1L ball mill jar, add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the batch;

[0116] (S2) The raw material of the batch prepared in step (S1) is put into a corundum crucible, heated from room temperature to 1450°C within 5 hours and kept at that temperature for 4 hours. After being taken out, it is cooled by blowing air with an electric fan. After cooling, the clinker that has not been pulverized by the air jet mill is obtained.

[0117] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.3 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0118] X-ray diffraction analysis showed that the prepared clinker without air jet milling was pure β-Ca2SiO4, while the particle size of the clinker after air jet milling was similar to that in Example 1.

[0119] The clinker prepared in this embodiment without air jet milling and the clinker prepared by air jet milling were mixed with deionized water at a water-cement ratio (w / c) of 0.4 to obtain a slurry. The obtained slurry was poured into a 4cm*4cm*4cm mold at room temperature for curing. After 24 hours, the sample was removed from the mold and cured for 1, 3, 7 and 28 days at 20±1℃ and 90±1% relative humidity, respectively. The compressive strength at each age was similar to that in Example 1.

[0120] Example 10: A mixture of calcium borosilicate, calcium stobolarate, diborate, and dihexaborate as a boron-containing crystal stabilizer.

[0121] This embodiment provides a method for preparing highly active β-Ca2SiO4 for cultural relic preservation, including the following steps:

[0122] (S1) Weigh 196.5g of calcium carbonate, 54.0g of silicon dioxide, 1.96g of calcium borosilicate, 2.06g of calcium staborite, 1.80g of diborate and 1.6g of hexaborate (in this example, the atomic ratio of boron atoms to silicon is 9%), add them to a 1L ball mill jar, add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the compound;

[0123] (S2) The raw material of the batch prepared in step (S1) is put into a corundum crucible, heated from room temperature to 1450°C within 5 hours and kept at that temperature for 4 hours. After being taken out, it is cooled by blowing air with an electric fan. After cooling, the clinker that has not been pulverized by the air jet mill is obtained.

[0124] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.4 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0125] X-ray diffraction analysis showed that the prepared clinker without air jet milling was pure β-Ca2SiO4, while the particle size of the clinker after air jet milling was similar to that in Example 1.

[0126] The clinker prepared in this embodiment without air jet milling and the clinker prepared by air jet milling were mixed with deionized water at a water-cement ratio (w / c) of 0.4 to obtain a slurry. The obtained slurry was poured into a 4cm*4cm*4cm mold at room temperature for curing. After 24 hours, the sample was removed from the mold and cured for 1, 3, 7 and 28 days at 20±1℃ and 90±1% relative humidity, respectively. The compressive strength at each age was similar to that in Example 1.

[0127] Comparative Example 1: Boric acid as a crystal stabilizer

[0128] (S1) Weigh 196g of calcium carbonate, 57.6g of silicon dioxide, and boric acid (in this comparative example, the atomic ratio of boron atoms to silicon is 4%), add them to a 1L ball mill jar, and add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the batch.

[0129] (S2) The raw material of the batch prepared in step (S1) is put into a corundum crucible, heated from room temperature to 1450°C within 5 hours and kept at that temperature for 4 hours. After being taken out, it is cooled by blowing air with an electric fan. After cooling, the clinker that has not been pulverized by the air jet mill is obtained.

[0130] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.3 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0131] The X-ray diffraction pattern of the prepared clinker without air jet milling is shown below. Figure 5 As shown, the results indicate that the synthesized clinker, which was not subjected to air jet milling, was almost entirely composed of the γ-Ca2SiO4 phase. Figure 5 The term "γ-C2S" refers to the γ-Ca2SiO4 phase. This is because boric acid volatilizes significantly at high temperatures and fails to act as a crystal stabilizer. A test sample made from the prepared clinker pulverized by an air jet mill failed to solidify after 28 days under natural conditions, indicating that γ-Ca2SiO4 lacks hydration activity.

[0132] Comparative Example 2: Calcium borosilicate as a boron-containing crystal stabilizer

[0133] (S1) Weigh 196g of calcium carbonate, 57.6g of silicon dioxide, and 6.4g of calcium borosilicate (in this comparative example, the atomic ratio of boron atoms to silicon is 4%), add them to a 1L ball mill jar, and add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the batch;

[0134] (S2) The raw material of the batch prepared in step (S1) is loaded into a corundum crucible, heated from room temperature to 1450°C within 5 hours and held for 4 hours, and then cooled with the furnace temperature to obtain clinker that has not been pulverized by the air jet mill.

[0135] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.3 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0136] X-ray diffraction analysis showed that the prepared clinker, which was not pulverized by air jet mill, was pure β-Ca2SiO4.

[0137] The clinker prepared by air jet milling in this comparative example was uniformly mixed with deionized water at a water-cement ratio (w / c) of 0.4 to obtain a slurry. The resulting slurry was poured into a 4cm*4cm*4cm mold at room temperature for curing. After 24 hours, the sample was removed from the mold and cured for 3, 7 and 28 days at 20±1℃ and 90±1% relative humidity, respectively. The results are shown in Table 1.

[0138] Comparative Example 3 without the addition of boron-containing crystal stabilizer

[0139] (S1) Weigh 196g of calcium carbonate and 58.8g of silicon dioxide, add them to a 1L ball mill jar, and add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the batch.

[0140] (S2) The raw material of the batch prepared in step (S1) is put into a corundum crucible, heated from room temperature to 1450°C within 5 hours and kept at that temperature for 4 hours. After being taken out, it is cooled by blowing air with an electric fan. After cooling, the clinker that has not been pulverized by the air jet mill is obtained.

[0141] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.3 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0142] X-ray diffraction patterns of the prepared clinker without air jet milling showed that almost all of the synthesized clinker consisted of the γ-Ca2SiO4 phase. A test slurry made from the prepared air jet milled clinker failed to solidify after 28 days under natural conditions, indicating that γ-Ca2SiO4 lacks hydration activity.

[0143] Comparative Example 4 without the addition of boron-containing crystal stabilizer

[0144] (S1) Weigh 196g of calcium carbonate and 58.8g of silicon dioxide, add them to a 1L ball mill jar, and add 400mL of water; after ball milling for 24h, dry at 105℃ for 24h, and then grind with an electric grinder for 2h to obtain the raw material of the batch.

[0145] (S2) The raw material of the batch prepared in step (S1) is loaded into a corundum crucible, heated from room temperature to 1450°C within 5 hours and held for 4 hours, and then cooled with the furnace temperature to obtain clinker that has not been pulverized by the air jet mill.

[0146] (S3) The clinker obtained in step (S2) without air jet milling is pulverized by air jet mill to obtain clinker pulverized by air jet mill, wherein the pressure of the feeding nozzle during air jet mill pulverization is 0.3 MPa and the pressure of the pulverizing nozzle is 0.6 MPa.

[0147] X-ray diffraction patterns of the prepared clinker without air jet milling showed that almost all of the synthesized clinker consisted of the γ-Ca2SiO4 phase. A test slurry made from the prepared air jet milled clinker failed to solidify after 28 days under natural conditions, indicating that γ-Ca2SiO4 lacks hydration activity.

[0148] The compressive strength of the clinker prepared by air jet mill in Example 1, the clinker prepared by air jet mill in Comparative Example 2, and the materials prepared in existing literature were compared. The results are shown in Table 1. Table 1 shows that the compressive strength of the clinker prepared by air jet mill in Example 1 at all ages is much higher than the values ​​reported in existing literature, demonstrating the superiority of the clinker prepared by air jet mill in Example 1.

[0149] Table 1 Comparison of mechanical strength of various materials

[0150]

[0151]

[0152] The relevant literature mentioned in Table 1 is as follows:

[0153] Literature [1]: JTZhang, WSZhang, JYYe, XHRen, L.Liu, WGShen, Influence of alkaline carbonates on the hydration characteristics of β-C2S. Constr.Build.Mater.296 (2021).

[0154] Literature [2]: P.Koutník, A.Soukup, P.Bezucha, J.Kohout, Properties of mortars based on β-belite-metakaolinite-hydrated lime binder system, Constr.Build.Mater.253(2020).

[0155] Literature [3]: N.El Fami, H.Ez-zaki, A.Diouri, O.Sassi, A.Boukhari, Improvement of hydraulic and mechanical properties of dicalcium silicate by alkalineactivation, Constr.Build.Mater.247(2020)

[0156] Literature [4]: ​​Luo K, Zhang W, Ye J, et al. Mechanism of interaction between hydration-carbonation of C2S [J]. Construction and Building Materials, 2024, 412: 134891.

[0157] Literature [5]: Zhang W, Zhang J, Ye J, et al. Hydration kinetics and microstructure development of normal and NaAlO2-activated Al-dopedβ-C2Spastes[J]. Journal of the American Ceramic Society, 2022, 105(3): 2221-2233.

[0158] Example 11

[0159] This embodiment provides an application of highly active β-Ca2SiO4 (β-Ca2SiO4 prepared by air jet milling in Example 1) in cultural relic preservation. The specific application process is as follows:

[0160] (A1) After uniformly mixing the β-Ca2SiO4 pulverized by air jet mill prepared in Example 1 with 80-mesh sand at a mass ratio of 1:1, water and polycarboxylate superplasticizer were added at a water-binder ratio of 0.4 (the mixed addition amount of water and polycarboxylate superplasticizer was 0.3% of the mass of β-Ca2SiO4 pulverized by air jet mill). The mixture was then rapidly stirred for 5 minutes using an electric mixer to obtain mortar.

[0161] (A2) Based on the actual direction of the surface cracks on the north side of Dazu Rock Carvings, V-shaped grooves were opened. Using tools such as small art scrapers and scrapers, the well-mixed mortar was filled into the V-shaped grooves, and the filling density of the sealing material was ensured as much as possible. After filling, the parts that exceeded the cracks were trimmed and wiped clean to minimize the impact of the sealing material on the rock surface. Finally, the surface of the sealing material was covered with damp cloth strips, and water was sprayed twice a day for 15 days during the curing period to ensure that the sealing material achieved good performance under the necessary high humidity curing conditions.

[0162] pass Figure 6 It can be observed that the sealing material after the sealing treatment has a good bonding effect with the rock body of Dazu Rock Carvings, and no obvious cracks appeared after 6 months; proving that the β-Ca2SiO4 prepared by this invention has a good effect in practical applications.

[0163] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the interpretation of the present invention, without departing from the scope of the invention, should be within the protection scope of the present invention.

Claims

1. A highly active β-Ca2SiO4 for the preservation of cultural relics, characterized in that, It was prepared by solid-phase synthesis of calcium carbonate, silicon dioxide and boron-containing crystal stabilizer; The boron-containing crystal stabilizer is selected from one or more of boron-calcium compounds or calcium-boron-silicon compounds; The boron-calcium compound is selected from one or more of calcium metaborate, calcium borate, or calcium staborite; The calcium-boron-silicon compound is selected from one or more of calcium borosilicate and calcium borosilicate. The preparation of highly active β-Ca2SiO4 for cultural relic preservation specifically includes the following steps: (S1) After mixing calcium carbonate, silicon dioxide and boron-containing crystal stabilizer, the mixture is ball-milled to obtain raw feed. (S2) The raw materials prepared in step (S1) are calcined and then rapidly cooled to obtain β-Ca2SiO4 that has not been pulverized by an air jet mill. Alternatively, the raw materials prepared in step (S1) can be calcined, rapidly cooled, and then pulverized by an air jet mill to obtain β-Ca2SiO4 pulverized by an air jet mill. In step (S1), the number of calcium atoms in calcium carbonate is twice the number of silicon atoms in silicon dioxide; the number of boron atoms in the boron-containing crystal stabilizer is 1-10% of the number of silicon atoms in silicon dioxide. In step (S2), the calcination process is carried out at a temperature of 800~1500℃ for 1~24h.

2. A highly active β-Ca2SiO4 for cultural relic preservation as described in claim 1, characterized in that, The highly active β-Ca2SiO4 used for cultural relic protection is selected from either β-Ca2SiO4 that has not been pulverized by an air jet mill or β-Ca2SiO4 that has been pulverized by an air jet mill.

3. The highly active β-Ca2SiO4 for cultural relic preservation according to claim 1, characterized in that, In step (S1), the ball milling process is selected from either dry ball milling or wet ball milling.

4. The highly active β-Ca2SiO4 for cultural relic preservation according to claim 1, characterized in that, During the dry ball milling process, the rotation speed is 300~350 r / min and the time is 40~60 min.

5. The highly active β-Ca2SiO4 for cultural relic preservation according to claim 1, characterized in that, During the wet ball milling process, a dispersant is added at a rate of 0.8% to 1.2% of the combined mass of calcium carbonate, silica, and boron-containing crystal stabilizer. The rotation speed is 330 to 360 r / min, and the time is 20 to 28 h. After the wet ball milling is completed, the mixture is dried and pulverized.

6. The highly active β-Ca2SiO4 for cultural relic preservation according to claim 1, characterized in that, In step (S2), during the air jet mill pulverization process, the pressure of the feeding nozzle is 0.3~0.4MPa, and the pressure of the pulverizing nozzle is 0.6MPa; The particle size D of β-Ca2SiO4 pulverized by air jet mill 90 Less than 20μm.

7. The application of the highly active β-Ca2SiO4 for cultural relic protection as described in any one of claims 1 to 6 in the preparation of cultural relic protection products.

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