PHYSICOCHEMICAL ANALYSIS OF INORGANIC COMPOUNDS Tennium reciprocal system Mg, Ca//Cl, MnO4

Abstract Using a set of methods of physicochemical analysis, the ternary reciprocal system Mg, Ca//Cl, MnO4 was studied for the first time. The purpose of this work is due to the need to develop low-melting electrolytes for the electrical production of molybdenum coatings from ionic melts. In this regard, it is of interest to study the melting diagram of the ternary mutual system Mg, Ca//Cl, MnO4 in order to determine the solubility of powellite (CaMnO4) in magnesium chloride and mixtures of magnesium and calcium chlorides. The studies were carried out by differential thermal analysis using a synchronous thermal analyzer STA 449 F3 Jupiter (Netzsch). This device is a measuring complex that combines the functions of a differential scanning calorimeter and analytical scales. Particular attention during the work was paid to the preparation of pure anhydrous chlorides of magnesium and calcium. To outline the liquidus surface of the system, polythermal sections were studied in the heating and cooling mode. Based on these sections and two diagonal sections, a projection of the crystallization surface of the system onto the square of compositions was constructed, and the given isotherms made it possible to outline the fields of the initial components and the identified compositions. The obtained results indicate a significant solubility of powellite in magnesium chloride and mixtures of magnesium and calcium chloride, as a result of which the compositions of the points of nonvariant equilibrium of the studied system can be used as electrolytes for the electrodeposition of molybdenum from molten media.