Dragana Živković

Kinetics and mechanism of the thermal decomposition of M(NO3)2.nH2O (M=Cu, Co, Ni)

This paper presents the results of simultaneous DTA-TG-DTG and DSC studies on the thermal decomposition of Cu(NO3)2·3H2O, Co(NO3)2·6H2O and Ni(NO3)2·6H2O in an air atmosphere. The mechanism and enthalpies of the investigated processes were determined, as well as the kinetic parameters of the processes run under non-isothermal conditions by means of Kissingers method. The dependence of the activation energy on the ionic radius of the cations building up the crystal lattices of the investigated compounds was also studied.

Kinetics and mechanism of Sb2S3 oxidation process

Abstract This paper presents the results of experimental investigations of Sb 2 S 3 oxidation process in an air atmosphere. Methods of investigation, including DTA–TG–DTG and DSC analysis, enabled the determination of heat effects, kinetic parameters and mechanism of the investigated process.

Comparative thermodynamic study and phase equilibria of the Bi-Ga-Sn ternary system

Abstract The results of a comparative thermodynamic investigation of the Bi – Ga – Sn system, giving experimentally obtained results and calculated thermodynamic data, are presented in this paper. Oelsen calorimetry was performed for the experimental determination of thermodynamic properties in the section with a molar ratio of Bi: Sn = 1: 3, while the Redlich – Kister – Muggianu method was applied for thermodynamic predicting in the sections with molar ratio Bi: Sn = 1: 3, 1: 1, 3: 1. Thermodynamic parameters – partial and integral molar quantities, as well as gallium activities, were determined at the temperatures of 873 and 973 K. Phase equilibria in the Bi – Ga – Sn ternary system have been studied experimentally – using differential thermal analysis and scanning electron microscopy with energy dispersive X-rays, while the calculation of phase diagram was done according to the CALPHAD method. The phase diagram of the section with molar ratio of Bi: Sn = 1: 3 is given, as well as the phase diagram of the ternary Bi – Ga – Sn system at 373 K.

Predicting of the thermodynamic properties for the ternary system Ga-Sb-Bi☆

R-function method for predicting the ternary thermodynamic properties from its binary ones was applied to the ternary system Pb−Bi−Mg. Activities, activity coefficients, partial and integral molar quantities for Pb, Bi and Mg for the quasibinary sections Pb-X (X=B, C, D, E, F) in the investigated ternary system Pb−Bi−Mg calculated by means ofR-function method are given in this paper. Also, it was determined that results obtained byR-function method reach a good agreement with the experimental results obtained by Oelsen calorimetry.

Comparative study of thermodynamic predicting methods applied to the Pb–Zn–Ag system

Abstract Results of thermodynamic predicting methods applied to the ternary Pb–Zn–Ag system are presented in this paper. The Chous model has been used to predict the thermodynamic properties of the investigated system, while the other traditional models such as Toop, Hillert, Kohler and Muggianu are also included in calculations for comparison and discussion. The calculated data could be useful in further interpretation of the phenomena occurring in the Parkes process of desilverizing in the extractive metallurgy of lead.

Comparative thermodynamic analysis of the Bi-Ga0.1Sb0.9 section in the Bi-Ga-Sb system

Results of the comparative thermodynamic analysis of the Bi-Ga0.1Sb0.9 section in theBi-Ga-Sb system are given in this paper. Experimental calorimetric investigations were done according to Oelsens method, while for the thermodynamic prediction Chous general solution model was applied. Activities, activity coefficients, partial molar quantities for bismuth and integral molar quantities were obtained at a temperature of 1073 K. Based on obtained cooling curves, DTA and SEM results for the investigated samples, phase diagram of the investigated section is constructed and presented in this paper, too.

Comparative Thermodynamic Investigation of the Bi–GaSb System

Results of the thermodynamic investigations in the Bi–GaSb system are presented in this paper. Thermodynamic characteristics experimentally determined by Oelsens calorimetric method were compared with values predicted by different thermodynamic predicting methods (general solution model, Kohler, Muggianu, Toop, Hillert) at the temperature of 1073 K. Also, based on the obtained cooling curves and microstructure analysis of the investigated samples by optical microscopy, phase diagram of the Bi–GaSb system was investigated and compared with literature data.

Thermal study and mechanism of Ag2S oxidation in air

The results of thermal study and mechanism of the oxidation process of synthetic Ag2S in air are presented in this article based on the comparative analysis of DTA and XRD results, as well as by constructed phase stability diagrams (PSD) for the Ag–S–O system.

Comparative thermodynamic analysis and phase diagram prediction of the Ga-Sn-Zn system

Abstract The results of comparative thermodynamic analysis and phase diagram prediction of the Ga – Sn – Zn system are presented in this work. The thermodynamic study was done experimentally – using Oelsen calorimetry, for the section Ga – SnZneut, and analytically – according to the general solution model, for the whole system. Main thermodynamic quantities – integral and partial molar Gibbs excess energies, activities and activity coefficients were calculated over a wide temperature range. Additionally, the phase diagram of the section Ga – SnZneut was investigated using differential thermal analysis and predicted using the CALPHAD method. Comparison with available literature data showed reasonable agreement. The liquidus projection of the ternary Ga – Sn – Zn was also calculated.

Phase diagram investigation and thermodynamic study of Os-B system

The constitution of the Os-B system was investigated in this work. The phase regions were determined by metallographic investigations. The existence of the following borides was confirmed: OsB1.1 (hex.), Os2B3 (hex.) and OsB2 (orthorh.), while the new high temperature Os2B3 compound with a not yet identified structure was observed. OsB1.1 melts congruently at 1820±15°C and OsB2 at 1870±15°C, while the solid solubility of B in Os was found to be less than 0.5 at%B. Considering thermodynamic study of this system, the activities and activity coefficients for osmium and boron were determined in temperature interval 3300-3500 K, based on the known liquidus and solidus lines from phase diagram, according to calculation procedure given by Rao and Belton.