The effect of modifying components, including Al2O3, SiO2, B2O3 , and CaO, on the melting of basalt and crystallization of basalt glasses intended for continuous manufacture of fiber was investigated. It was ascertained that the introduction of complex aluminum- and boron-containing modifiers effects a 15 – 20

The synthesis and study of model glasses of the MgO–CaO–Fe2O3–Al2O3–SiO2 system, which is the base for obtaining continuous basalt fiber, has been carried out. Systematized data on the effect of components on the glasses structure and the sequence of phase separation processes occurring during their heat treatment have been obtained. It is shown that during phase separation, crystalline phases are separated in the following sequence: magnetite–pyroxene–plagioclase with a predominance of the anorthite component. Glasses of the MgO–CaO–Fe2O3–Al2O3–SiO2 system were modified by adding B2O3, and the active role of this component in the processes of glass formation and crystallization was shown. The ratio of glass-forming and modifying components of model glasses is established, at which an increase in the strength of glasses from 110 to 180 MPa is achieved. Based on the study of the technological properties of model glasses and strength characteristics, components were determined for modifying basalt glasses in order to increase the strength of the fiber.

The synthesis and study of model glasses of the MgO–CaO–Fe 2 O 3 –Al 2 O 3 –SiO 2 system, which is the base for obtaining continuous basalt fiber, has been carried out. Systematized data on the effect of components on the glasses structure and the sequence of phase separation processes occurring during their heat treatment have been obtained. It is shown that during phase separation, crystalline phases are separated in the following sequence: magnetite–pyroxene–plagioclase with a predominance of the anorthite component. Glasses of the MgO–CaO–Fe 2 O 3 –Al 2 O 3 –SiO 2 system were modified by adding B 2 O 3 , and the active role of this component in the processes of glass formation and crystallization was shown. The ratio of glass-forming and modifying components of model glasses is established, at which an increase in the strength of glasses from 110 to 180 MPa is achieved. Based on the study of the technological properties of model glasses and strength characteristics, components were determined for modifying basalt glasses in order to increase the strength of the fiber.

A comprehensive study was performed of various types of aluminum-containing raw materials and their effect on glass formation during smelting of borosilicate glasses for type-E fiber. It is shown that on use of non-metallurgical alumina, as compared with metallurgical alumina, disthene-sillimanite concentrate, and kaolin, a savings of energy resources for glass formation processes from 2.64 to 16.30% obtains.

A series of Na 2 O-MgO-TiO 2 -Al 2 O 3 -B 2 O 3 -SiO 2 glasses promising as sealants for solid oxide fuel cells are prepared. The glassy state is confirmed by X-ray diffraction analysis, and the elemental composition is determined by inductively coupled plasma atomic emission spectroscopy. The coefficient of thermal expansion (CTE) is calculated from the dilatometric data; it varies within (69–77) × 10 −7 K −1 and increases with the MgO to Al 2 O 3 concentration ratio. The CTE calculation by the Appen method gives the results that are underestimated by 5–8% relative to the experimental data. The temperature dependences of the heat capacity of the glasses are determined by differential scanning calorimetry and calculated using the Kopp-Neumann rule. Comparison of the calculated values with the experimental data shows that the Kopp-Neumann rule is observed for the systems under consideration with relatively high accuracy. The sensitivity of different methods in determination of the glass transition point has been evaluated.

A series of Na2O-MgO-TiO2-Al2O3-B2O3-SiO2 glasses promising as sealants for solid oxide fuel cells are prepared. The glassy state is confirmed by X-ray diffraction analysis, and the elemental composition is determined by inductively coupled plasma atomic emission spectroscopy. The coefficient of thermal expansion (CTE) is calculated from the dilatometric data; it varies within (69–77) × 10−7 K−1 and increases with the MgO to Al2O3 concentration ratio. The CTE calculation by the Appen method gives the results that are underestimated by 5–8% relative to the experimental data. The temperature dependences of the heat capacity of the glasses are determined by differential scanning calorimetry and calculated using the Kopp-Neumann rule. Comparison of the calculated values with the experimental data shows that the Kopp-Neumann rule is observed for the systems under consideration with relatively high accuracy. The sensitivity of different methods in determination of the glass transition point has been evaluated.

The technological properties of basaltic melts and glasses based on basalt-colemanite compositions were investigated. It was established that the production temperature of continuous fiber when using boron-containing compositions can be lowered owing to the reduction of the viscosity, liquidus temperature, and crystallization capacity of the melt.

ТЕПЛОФИЗИЧЕСКИЕ СВОЙСТВА СТЕКОЛ СИСТЕМЫ Na20 -M g 0 -T i0 2 -A l2 0 3 -B 2 0 3-S i0 2 И ПЕРСПЕКТИВЫ ИХ ПРИМЕНЕНИЯ ДЛЯ ГЕРМЕТИЗАЦИИ ТВЕРДООКСИДНЫХ ТОПЛИВНЫХ ЭЛЕМЕНТОВ © Л. Ф. Папко1, М. В. Дяденко1, А. В. Кузьмин2'3, Д. А. Крайнова2'3, Н. С. Саєтова2, А. А

The results of an investigation of glasses and glass ceramic materials synthesized in the system R 2 O(Na 2 O, K 2 O)–MgO–CaO–Al 2 O 3 –SiO 2 using granitoid screenings from the Mikashevichskoe deposit are reported. Glass ceramic materials which in terms of the performance characteristics can be used as proppants in the oil and gas industry were obtained.

Представлены результаты исследования стекол систем SrO – ZnO – Al2O3 – SiO2 и Na2O – MgO – Al2O3 − SiO2 с целью разработки на их основе высокотемпературных герметиков для твердооксидных топливных элементов. По результатам изучения кристаллизационной способности стекол и формирования спаев на их основе установлено, что вакуумплотные соединения могут быть получены на основе кристаллизующихся стекол системы Na2O − MgO(CaO) – Al2O3 − SiO2. В стеклокристаллических материалах на основе стекол данной системы в качестве кристаллических фаз выделяются диопсид MgCa[Si2O6] и нефелин Na[Si2Al2O8]. Выделение данных фаз обеспечивает достижение высоких показателей ТКЛР стеклокристаллических материалов и, как следствие, согласование с материалами твердооксидных топливных элементов. В результате проведенных исследований синтезированы стеклокристаллические материалы, которые по технологическим и термическим свойствам могут быть использованы в качестве стеклогерметика твердооксидных топливных элементов

Представлены результаты исследования борсодержащих и безборных стекол для производства непрерывного волокна типа Е, полученных на основе систем MgO – CaO – Al2O – B2O3 – SiO2 и MgO – CaO – Al2O3 – SiO2.По результатам изучения процессов стеклообразования при синтезе боросиликатных стекол установлено, что с повышением содержания оксида бора температура получения гомогенного расплава снижается от 1400 до 1300°С. При синтезе безборного стекла процессы стеклообразования завершаются при температуре 1400–1450°С. При переходе от борсодержащих к безборным составам стекол возрастает высокотемпературная вязкость и верхняя температура кристаллизации, что требует повышения температуры формования непрерывного волокна на 60–80°С.

Glasses with refractive index 1.60 – 1.65, density 2.80 – 3.08 g/cm 3 and dispersion coefficient ≥ 45 have been developed on the basis of the system Na 2 O(K 2 O)–MgO–CaO–BaO–ZnO–B 2 O 3 –SiO 2 . These glasses are recommended for use in ophthalmologic lenses.

The effect of concentration and structural factors on the character of the temperature dependence of the viscosity of glasses in the systems K 2 O–B 2 O 3 –SiO 2 and Na 2 O–B 2 O 3 –SiO 2 in the range 10 9 – 10 4 Pa ⋅ sec is determined. It is shown that the effect of boron and potassium oxides on the temperature dependence of the viscosity near the transition from the liquid into the plastic state is complex.

Partial sections of the system BaO–La2O3–B2O3–TiO2–SiO2 were studied and the regions of glassy-state stability are determined. The regular effects of titanium, lanthanum, and barium oxides on the crystallizability of the experimental glasses and on the optical and thermal properties were established. An optical glass with refractive index 1.81, average dispersion 0.0187, and CLTE 76.8 × 10–7 K–1 was obtained. This glass can be recommended for high refractive-index optical lenses as well as for the light-guiding core in optical fibers.

The features of the effect of the composition and structure of glasses of the systems Na 2 O – CaO – B 2 O 3 – SiO 2 and Na 2 O – CaO – B 2 O 3 – Al 2 O 3 – SiO 2 on the temperature curve of the viscosity in the 10 10 – 10 4 Pa · sec range were established. The important effect of phase separation processes—liquation and crystallization—on the viscosity indexes in the temperature region of the transition from the plastic to the liquid state was demonstrated.

The possibility of using glauconite-bearing sedimentary rocks from Belarus in the form of glauconite sand and concentrated glauconite as aluminosilicate materials is established. The main physicochemical properties of the synthesized materials are identified, and the color characteristics of glasses and formation specifics of the structure and phase composition of glaze coatings and glass ceramic materials are investigated.

The effect of modifiers of the Na2O(K2O) - B2O3 - Al2O3 - SiO2 glass-forming system on the nature of phase separation is studied. Certain regularities for the formation of a transparent glaze layer under accelerated firing conditions are established.