Выявлены координаты тройных нонвариантных точек, стабильное триангулирующее сечение, поля первичных кристаллизаций исходных компонентов K2WO4, KBO2, K2CO3, изучены политермические разрезы в двух трехкомпонентных системах А-В и K2WO4 -Ê1-Е1 и е2-е3 и КBO2–Ē2–Е2

By differential thermal analysis using the calculation-experimental method, the phase diagram of the quaternary system NaBO2–Na2CO3–Na2WO4–K2WO4 was studied, and the coordinates of ternary eutectics and two quaternary eutectics were determined: E 1 □ (530°C, 5.6% NaBO2, 30% Na2CO3, 55.3% Na2WO4, 9.1% K2WO4). It was shown that the calculated and experimental data on the coordinates of the quaternary eutectics agree satisfactory.

The phase diagrams of the ternary reciprocal systems Na,K||BO 2 ,CO 3 and Na,K||BO 2 ,Cl were studied for the first time by a calculation-experimental method and by differential thermal analysis. Analytical models of phase equilibrium states were derived, and the coordinates of eutectics were found to be (680°C, 32 mol % NaBO 2 , 68 mol % KCl) and (648°C, 9 mol % NaBO 2 , 45.5 mol % NaCl, 45.5 mol % KCl). Binary solid solutions based on metaborates and carbonates of sodium and potassium were shown to be stable. The possibility of synthesizing tungsten oxide bronzes in a eutectic melt in the ternary system NaBO 2 –NaCl–КCl was revealed.

The phase diagrams of the ternary systems NaCl–NaBO2–KCl, NaCl–KCl–Na2CO3, and KCl–NaBO2–Na2CO3 and the quaternary system NaCl–NaBO2–Na2CO3–KCl were studied by the calculation–experimental method and differential thermal analysis. Analytical models of phase equilibria were obtained, and the coordinates of ternary eutectics and a quaternary eutectic. It was shown that low-melting eutectic melts can be used as media for synthesizing oxide tungsten bronzes.

The phase diagrams of the ternary reciprocal systems Na,K‖BO2,MoO4 and Na,K‖BO2,WO4 were studied for the first time by a calculation-experimental method and differential thermal analysis. The coordinates were determined for binary eutectics of the diagonal stable sections NaBO2-K2MoO4(K2WO4) and the ternary invariant points e(55 mol % NaBO2, 45 mol % K2MoO4, 740°C), e(55 mol % NaBO2, 45 mol % K2WO4, 730°C), E(4.5 mol % NaBO2, 78 mol % Na2MoO4, 17.5 mol % K2MoO4, 652°C), E(4.5 mol % NaBO2, 78 mol % Na2WO4, 17.5 mol % K2WO4, 643°C), P2(5 mol % NaBO2, 56 mol % Na2MoO4, 39 mol % K2MoO4, 673°C), P2(5 mol % NaBO2, 56 mol % Na2WO4, 39 mol % K2WO4, 671°C). Binary solid solutions based on sodium and potassium metaborates were shown to be stable. Analytical models of phase equilibrium states of the ternary reciprocal systems Na,K‖BO2,MoO4(WO4) were obtained, which enable one to calculate melting (crystallization) points and construct isotherms at any given composition. The specific heats of melting of samples of invariant compositions were found by quantitative differential thermal analysis.

Расчетно-экспериментальным методом и методом дифференциального термического анализа изучена фазовая диаграмма четырехкомпонентной системы КCl КBO2 К2CO3 К2МоO4. Получены аналитические модели фазовых равновесных состояний и выявлены координаты четверной эвтектики: 550°C, 50% КCl, 8% КBO2, 23% К2CO3, 19% К2МоO4.

The phase diagram of the quaternary system KCl-KBO2-K2CO3-K2MoO4 was studied by a calculation-experimental method and differential thermal analysis. Analytical models of phase equilibrium states were obtained, and the coordinates of a quaternary eutectic were determined: 550°C, 50% KCl, 8% KBO2, 23% K2CO3, and 19% K2MoO4.