This study investigates the production and characterization of basalt continuous fibers (BCFs) with varying oxide contents (including Na2O, SiO2, CaO, TiO2, and Al2O3), derived from modified basalt bulk glasses. The fibers were created through a two-stage process that included the preparation of basalt glasses followed by fiber drawing. A key focus of the research was on evaluating the mechanical properties of BCF after low-temperature treatments. Tensile testing revealed that the maximum tensile strength of the fibers was 1915 MPa at room temperature, which decreased to 1714 MPa at −196 °C, representing a shift of −10.5%. The addition of sodium oxide not only broadened the fiber-forming temperature range but also increased the strength to 2351 MPa. However, significant reductions in strength were observed at cryogenic temperatures, particularly for the Na-rich sample, which experienced a decrease of 32.8%. These findings highlight the importance of optimizing oxide content and minimizing hydroxyl (OH) groups to enhance the performance of basalt fibers in low-temperature applications, positioning them as viable materials for use in extreme environments.

This paper reported the melting process and crystallization behavior of basalt ores from three different regions in China. The findings indicated that during the melting process of basalt, different minerals gradually melted as the temperature increased, and the spinel phase in the ore exhibited the most significant resistance to the temperature. Continuous basalt fibers (BFs) were obtained by using these ores in a fiber-spinning facility. The analysis of fiber structure and tensile strength revealed that an increased content of network former inhibited crystallization while enhancing the polymerization degree of the filaments. Conversely, a higher degree of polymerization was associated with increased fiber strength. More interestingly, a higher content of MgO and FeO facilitated the precipitation of spinel during the fiber formation, leading to the inferior strength of the fiber. The findings of this work provide technical guidance for the preparation of high-performance BF.

Alkali resistance is a critical factor for the long-term performance of glass fibers in cementitious composites. While zirconium oxide doping has proven effective in enhancing the durability of basalt fibers, its high cost and limited solubility motivate the search for viable alternatives. This study presents the first systematic investigation of titanium dioxide (TiO2) doping in basalt-based glasses across a wide compositional range (0–8 mol%). X-ray fluorescence and diffraction analyses confirm complete dissolution of TiO2 within the amorphous silicate network, with no phase segregation. At low concentrations (≤3 mol%), Ti4+ acts as a network modifier in octahedral coordination ([TiO6]), reducing melt viscosity and lowering processing temperatures. As TiO2 content increases, titanium in-corporates into tetrahedral sites ([TiO4]), competing with Fe3+ for network-forming positions and displacing it into octahedral coordination, as revealed by Mössbauer spectroscopy. This structural redistribution promotes phase separation and triggers the crystallization of pseudobrukite (Fe2TiO5) at elevated temperatures. The formation of a protective Ti(OH)4 surface layer upon alkali exposure enhances chemical resistance, with optimal performance observed at 4.6 mol% TiO2—reducing mass loss in NaOH and seawater by 13.3% and 25%, respectively, and improving residual tensile strength. However, higher TiO2 concentrations (≥5 mol%) lead to pseudobrukite crystallization and a narrowed fiber-forming temperature window, rendering continuous fiber drawing unfeasible. The results demonstrate that TiO2 is a promising, cost-effective dopant for basalt fibers, but its benefits are constrained by a critical solubility threshold and structural trade-offs between durability and processability.

In this work, the aim was to define the dependence of the strength of basalt fibers (BCF) on their chemical composition, characterized by two parameters: the NBO/T ratio and the acidity modulus Ma. It makes it possible to predict the change in the mechanical parameters of fibers from their composition, since basalt rocks have a significant drawback - the inconstancy of the chemical composition. Fibers of various chemical compositions were obtained based on 14 different basalt deposits. Pearson’s correlation coefficient for NBO/T and ultimate tensile strength was 0.79, and for acidity modulus and tensile strength it was 0.53. The tensile strength of tested fibers from different deposits ranges from 1495 to 3380 MPa. In addition, with the help of the Raman spectra analysis, it was confirmed that tensile strength can be largely determined by the influence of the chemical composition of basalts on their structure.

In this study, the morphologies and properties of basalt fibre (BF) treated at different temperatures in air atmosphere were studied. The results showed that the heat treatment caused the formation of crystals on fibre surface, which resulted in the alteration of BF from the paramagnetic material to the ferromagnetic one. The tensile strength of BF was reduced significantly upon thermal treatment, and such reduction occurred in three temperature ranges: i) Decomposition of organic sizing on fibre surface, which led to the exposure of more defect structures (100–400 °C), and the structural changes of BF may also occur; ii) Simultaneous relaxation of excessive enthalpy and structural anisotropy, which were responsible for the phase separation in the amorphous matrix in the fibre (500–600 °C); iii) Structural modification due to the formation of multifarious crystals in the fibre (700–1000 °C). The crystallization in BF began with spontaneous spinel phase formation, which was favored by the initial phase separation and the oxidation of Fe2+. The spinel crystals became nucleation sites for the formation of pyroxene structure, and this process was accompanied by the enrichment of Ca, Mg and Fe on fibre surface. Therefore, the inhibition of crystallization for BF was important to maintain the mechanical performance of filament under the continuous thermal conditions for practical applications.

The construction of a lunar base is considered to be an important step towards deep-space exploration by humanity, and will rely on the utilisation of in situ lunar resources. In this paper, we discuss the current knowledge on the feasibility of converting lunar soil to high-performance fibres that can be used for the construction of a lunar base. This fibre would be combined with further portions of lunar soil to generate fibre-reinforced composites, which is utilized as multi-functional materials for lunar base construction. We discuss and analyse the latest findings regarding the composition of lunar soil simulants and their fibrisation properties, and techniques for fibre spinning and system integration. Finally, we suggest how the achievements made so far could be applied to the construction of a lunar base.

Zirconium-rich basalt continuous fibers with zirconium oxide content from 5.1 to 8.1 wt% with the addition of 1% lanthanum oxide were obtained in a laboratory facility. The production temperature range were measured. It was shown that lanthanum oxide addition allows to decrease production temperature by 50 degrees and to make wider the production temperature range by 10 degrees. Weight loss and tensile strength loss of fibers after refluxing in alkali solution were determined. The weight loss after boiling in 1 M NaOH and 0.5 M Na2CO3 solution is comparable to the weight loss of zirconium-rich glass fibers (AR glass). The addition of lanthanum oxide leads to an increase in the tensile strength of Zr-rich basalt continuous fibers by 15-20%. Based on the obtained data, it can be concluded that the presented approach will not only improve the alkali resistance of basalt continuous fibers for reinforcing cements and concretes, but also significantly reduce their cost. (c) 2021 Elsevier Ltd. All rights reserved.

This paper presents a study of the influence of basalt rocks’ phase composition, acidity modulus, and structural parameter NBO/T on the tensile strength and elastic modulus of basalt continuous fibers (BCFs) derived from them. A series of BCF samples based on 14 different basalt deposits was obtained under equal conditions. The tensile strength and elastic modulus of the BCFs from different deposits vary in the ranges of 1495–3380 MPa and 58.2–78.7 GPa, respectively. Using the original method of quantitative phase analysis based on the Rietveld method, the phase compositions of the 14 deposits were defined. All deposits can be used to obtain BCFs. In the studied natural rocks, the main component is tectosilicates; the mass content of framework aluminosilicates is in the range of 16.5–3.3 mass percent. The second main component is inosilicates; the mass content of chain aluminosilicates is in the range of 6.0–58.0 mass percent. The correlations among phase composition, acidity modulus, ratio of non-bridging oxygens to tetrahedral cations, tensile strength, and elastic modulus of the BCFs from the 14 different basalt deposits were calculated. There were strong positive correlation between tectosilicate minerals mass content and elastic modulus [Pearson correlation coefficient (PCC) of 0.7] and strong negative correlation between content of chain and layered aluminosilicates and elastic modulus (PCC of − 0.74).

The article presents the results of a study, of the effect of basalt fiber materials on the corros1on resistance of pipe metals. The samples of basalt fibers were studied as a reason of corrosion. The tests were made according to ASTM G189 "Standard guide for laboratory simulat1on of corrosion under insulation". During the work, an experimental laboratory facility was designed to determine the corrosion rate under materials. To research the effect of the chemical composition of the samples on the corrosion process under fiber materials the influence of the leaching of chemically active anions after wetting and heating of basalt fiber were investigated. Based on the obtained results, the main factors contributing to the development of corrosion under insulation were determined, and recommendations for reduction were given. It was found that samples with open porosity showed a tower corrosion rate. The reported study was funded by RFBR according to the research project № 18-29-17068.

В работе рассмотрена возможность применения стадии ионного обмена в технологии получения базальтовых непрерывных волокон.В ходе выполнения работы на экспериментальной установке были получены непрерывные базальтовые волокна диаметром 10-12 мкм.Получение непрерывного волокна проводили на лабораторной установке, которая реализует двухстадийный процесс получения непрерывных волокон

Abstract In this article, the general information about aerogels as well as application areas of materials based on them are presented. Scientific and technical review on heat conductivity of aerogel-based thermal insulation materials was made. It was determined, that among the Russian studies the results of behaviour of these materials under high temperatures are not presented. Comprehensive studies of thermal characteristics, including heat conductivity values in temperature range of 10–650 °C (where 650 °C is the maximal operating temperature) for the thermal insulation rolled materials based on TiO2-aerogel DRT06-Z (Alison Aerogel) were carried out. The mathematical relationship between heat conductivity and operating temperature in range of 10–650 °C was determined. Using the obtained results, the calculation of thickness of insulation for the studied aerogel-based rolled materials was realized according to the construction rules SP 61.13330.2010, that can be applied for design of high-heat insulation for equipment and pipelines.

In this study, the properties of E-glass fiber (GF) (0.5 g) exposed to sulfuric acid (100 mL, c(H)+ = 0.1 mol/L) and potassium hydroxide (100 mL, c(OH)- = 0.1 mol/L) solutions were studied. The results showed that after acid treatment, the GF was damaged with decreased tensile strength, and spiral cracks developed on the fiber surface. Acid corrosion of the GF was mainly attributed to the depletion of metal ions in the GF, and the ion-depletiondepth model was proposed to explain the mechanism. In the alkali solution, the -Si-O-Si- bonds in the network structure of the GF were degraded by the OH- ions, resulting in the destruction of the glass network. It formed a corrosion layer with sheet-like nanostructures on the fiber surface, which prevented further attack of alkali ions on the fiber. Comparative results of the tensile strength of the treated GF confirmed that the filament was more susceptible to acid attack than alkali attack.

The present research focuses on the influence of phosphorus oxide additives on the structure and thermal properties of the basalt glasses, produced in the form of fibers, i.e., at very high quenching speed. Basaltic glass fibers with various P2O5 contents were produced in two stages. In the first stage, the bulk glasses were prepared by adding variable amounts of (NH4)4P2O7 to milled natural andesitic basalt in order to obtain samples containing 2, 4, and 6 wt % P2O5. In the second stage, the glass fibers were obtained using a laboratory-scale system. Basalt glass fibers were characterized by Raman spectroscopy to obtain information on the structure of the obtained fibers, and by DSC-TG and XRD analyses to determine the change in crystallization mechanism of basaltic fibers. The hydrostatic weighing was used for the determination of glasses density. An increase in the content of P2O5 to 6 wt % leads to a decrease in the density of glass fibers due to the polymerizing effect of phosphorus oxide. The obtained X-ray diffraction patterns indicate that all samples are X-ray amorphous. The Raman results show that the decrease in the intensity of the line corresponding to vibrations of the structural units Q2 (about 920 cm–1) with respect to the line corresponding to Q3 (about 1125 cm–1) is related to an increase of P2O5 content. This also indicates the increase in polymerization degree of glass structure. DSC and XRD data also found out the change of phase transformations order with an increase of phosphorus oxide. The crystallization in natural and modified basalt glass fibers begins with spontaneous spinel-like phase formations that become nucleation sites for the precipitation of monoclinic pyroxene as a major phase. With an increase in the P2O5 content, there is a tendency to a decrease in the pyroxene at higher temperature, as a result of which, the hematite crystallizes at lower temperatures. That is associated with the activation of liquation processes, accompanied by the formation of amorphous phases with different viscosities with an increase in the concentration of P2O5. In conclusion, all the obtained data indicate the prospect of using the proposed approach to obtain basalt glass fibers with enhanced thermal and mechanical stability.

This work presents the study of the dependence of the basalt continuous fibers (BCF) tensile strength on their chemical composition. 14 different basalt deposits were used to obtain continuous fibers by a laboratory scale system. Based on the data for more than 15 articles focused on natural basalt continuous fibers (32 different compositions) and experimental data of 14 experimental BCF series, the correlation of the tensile strength, the acid modulus and the NBO/T parameter was calculated. The PCC (pearson correlation coefficient) value of NBO/T and the tensile strength was 0.79, for acidity modulus and tensile strength -0.53. Raman data for experimental BCF confirm the significant influence of the chemical composition of basalts on their structure, which determines their tensile strength. With a decrease in NBO/T, the observed ratio between the Raman bands at low- and high- frequencies gradually increases.

The influence of low-frequency vibrational treatment on the crystallization of basalt wool fibers was studied. In this work, three series of samples were investigated. The first sample set was only one-sided heated at temperatures from 300 degrees C to 900 degrees C for 24 h. The second sample set was after only vibrational treatment with a frequency of 50 Hz and oscillations amplitude of 1 mm for 6-48 h. The third sample set was after simultaneous treatment of one-sided heating and vibration at temperatures from 300 degrees C to 600 degrees C with a frequency of 50 Hz and oscillations amplitude of 1 mm for 24 h. It is shown that at temperatures close to the glass transition temperature, vibration can influence on the relaxation processes in glasses and accelerate them. Mechanism of glass structure transformation in the basalt fiber does not change, but it starts at a slightly lower temperature. That is a consequence of an additional low-energy vibrational treatment. The vibrational treatment intensifies the crystallization process in basalt fibers and decreases the service temperature of the material by at least 40-50 degrees C.

In the present research the dependence of compositional variations on the basaltic glass fibers mechanical properties was explored. Addition of 15 mol % MgO or 5 mol % ZnO led to enhanced for tensile strength up to 43% and 47% and for modulus up to 13% and 25% respectively. The structure of basaltic glass fibers with varying MgO and ZnO contents was investigated by solid-state 29Si and 27Al nuclear magnetic resonance with magic angle spinning (MAS-NMR) and infrared (IR) spectroscopy. It was indicated that the increase of MgO and ZnO contents slightly decreased the degree of network polymerization. 27Al MAS NMR exhibit a peak consistent with tetrahedral aluminum units AlO4. The noticeable fraction peaks of narrow octahedral aluminum units AlO6 are observed. Presence of aluminum cations in coordination 4 and 6 was confirmed by IR spectroscopy. In order to study their crystallization ability the glasses were heated at various temperatures for various time periods with following self-cooling. The crystalline phases were identified by X-ray diffraction analysis. Obtained results have shown the possibility to increase mechanical properties of continuous fibers and composites on their base by 50–60%.

The present study explains the role of surface modification of constituent materials on composite material performance. The influence of silane and nano-hybrid coatings on mechanical properties of basalt fibers and composite materials on their base was investigated. Infrared spectroscopy indicated that modification of basalt fiber surface and nano-SiO2 was successfully applied. The surface modification leads to the significant increase in the tensile strength of basalt fibers compared to the non-coated fibers. The tensile strength of silane-treated fibers was established 23% higher than the non-coated fibers, indicating that silane plays a critical role in the strength retention of basalt fibers. Also it was pointed out that silane coupling agents can be used for the preparation of the nano-hybrid coating. Addition of SiO2 nanoparticles into the fiber surface was incorporated to enhance the interfacial bonding of basalt fiber reinforced epoxy composite.