The synthesis of MgAl 2 O 4 with an excess of 10% MgO (molar content) has been studied when a mixture of highly dispersed powders of aluminum and magnesium oxides is heated to 800 and 1100 ° C. The rate of diffusion mass flow of aluminum cations in the process of spinel synthesis was accelerated by introducing TiO 2 into Al 2 O , and the rate of mass flux of magnesium cations was slowed down by introducing MgO into Al 2 O 3 additives Na 2 O. In parallel, spinel was synthesized without additives. The results of the syntheses were investigated petrographically, using XRD and dissolution in HCl. The use of additives and an increase in the synthesis temperature led to a decrease in the solubility of the powder in HCl, which facilitated the approximation of the composition of the initially formed solid solutions of Al 2 O 3 in MgAl 2 O 4 to stoichiometric spinel. Il. 1, tab. 2, bibliography: 7 titles.
The processes of obtaining spinel-type pigments from a mixture of Al 2 O 3 and Co 2 O 3 with aluminum powder ASD- 4 and additions of MgO and ZnO by the method of self-propagating high-temperature synthesis (SHS). Blue and ultramarine pigments were obtained, their phase composition, IR spectra, structure and color characteristics were investigated. It is shown that the use of the SHS method is promising for obtaining temperature-resistant spinel-type pigments of blue-blue colors. Tab. 1, ill. 3, bibliography: 2 titles.
Experimental data on the synthesis of s- and d-group II zirconates and titanates by the deposition method are generalized. It was found that during alkaline deposition, a chemical interaction occurs between the components. Subsequent heat treatment of the resulting sediments allows the synthesis of substances with a perovskite-like structure, which are recommended to be used as white pigments to obtain paints suitable for decorating glass and enamel products. Tab. 3, ill. 3, bibliography: 11 titles.
New ceramic pigments obtained using unconventional raw materials - chicken and ostrich eggshells - are considered. Tab. 2, ill. 2, bibliography: 8 titles.
The influence of chalk, slag of the Severstal plant and Kachkanar slimes on the moisture expansion of ceramic facing tiles has been investigated. It has been found that chalk reduces moisture expansion most effectively, then slag and least of all Kachkanar sludge. Tab. 3, bibliography: 4 titles.
The mineralizing effect of additives of the natural fluorine-containing mineral topaz and boric acid on the synthesis of ceramic pigments with diopside and anorthite structures based on natural wollastonite has been investigated. The brightest palette was obtained at 1100 ° C. A clear advantage of topaz over the traditional mineralizer, boric acid, has been established. The obtained ceramic pigments have good chromophore properties, are stable at high firing temperatures, and can be widely used in ceramic production. Tab. 5, ill. 2, bibliography: 3 titles.
A technology has been developed for the synthesis of synthetic minerals (for example, spinel) using a low-temperature plasma torch. The diagnostic properties of spinel were determined. Tab. 1, bibliography: 9 titles.
The results of obtaining blue-blue cobalt-containing spinels by the method of self-propagating high-temperature synthesis are presented. The influence of the synthesis conditions and composition on the structure of the obtained compounds is shown. The SHS method makes it possible to obtain spinels, which can be used as ceramic pigments. Il. 4, bibliography: 6 titles.
It is shown that an increase in the strength characteristics of ceramic products molded from weakly sintered polymineral low-melting clay raw materials and calcareous clays occurs due to an increase in the total amount of montmorillonite component in the charge; organogenic nature of calcite of calcareous clays, which contributes to the creation of a local reducing environment during firing, influencing the transition of Fe 3+ to Fe 2+ and promoting earlier sintering of clay; the presence of gypsum impurities in calcareous clays, which is a strong flux. Tab. 2, bibliography: 8 titles.
The process of synthesis of sodium b-alumina under conditions of low-temperature nitrogen plasma has been investigated. It was found that the main product of the plasma-chemical reaction is sodium polyaluminate Na 2 O x nAl 2 O 3 of unknown structure, the homogeneity region of which is in the range n = 3.5 - 8.0. The features of phase transformations during heating of plasma-chemical synthesis products in the temperature range 600 - 1400 ° C have been studied. The formation of a phase with a b-alumina structure (b- and b "-Al 2 O 3 ) proceeds in several stages with the formation of intermediate metastable sodium polyaluminates. 5, bibliography: 6 titles.
