Živan 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.

Multi-criteria ranking of copper concentrates according to their quality – An element of environmental management in the vicinity of copper – Smelting complex in Bor, Serbia

The results of multi-criteria ranking of copper concentrates by their quality, according to their content of useful and harmful components, are presented in this paper. Cu, Ag and Au were taken as useful components, while Pb, Zn, As, Cd, Hg, Bi and Sb were considered as harmful with adequate weight parameters. Considering its specific role in copper metallurgy, sulfur in the concentrate was considered in two scenarios. In the first scenario S was considered as a useful and in the other one as a harmful component. The ranking is done by implementing the PROMETHEE/GAIA method with an additional implementation of the special PROMETHEE V method, using the standard limitations of the heavy metals content in the concentrate. In this way, it is possible to perform an optimization of the input charge for the copper extraction from two aspects. The first aspect covers benefits from the content of useful metals, while the second deals with the protection of the environment, considering the content of harmful components of the charge. Using multi-criteria decision making for the sake of ranking the quality of copper concentrates, as described in this paper, could be considered as a contribution to the methodology of forming the market price of this product.

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.

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.

The effect of TQM on employee loyalty in transition economy, Serbia

The concept of total quality management (TQM) emphasises continuous improvement which requires the participation of every individual in the company. Although much has already been said about people being the primary resource in an organisation practicing TQM, this area has been neglected by companies implementing TQM. The aim of this study was to determine critical factors of TQM practice that would positively impact employee satisfaction. Data for this study were obtained from three manufacturing companies, which have accepted TQM philosophy. Using structural equation modeling, the relationships between structural determinants of job satisfaction and employee loyalty were investigated. The results suggest that five, out of six, determinants are positively related to job satisfaction.

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 study of the Pb–Bi2Mg3 system

Abstract Results of the comparative thermodynamic study of the Pb–Bi 2 Mg 3 system, obtained experimentally by Oelsen calorimetry and calculated by different predicting methods (general solution model, Toop, Hillert, Kohler, Muggianu) are given in this paper. Corresponding analytical expressions for the lead partial molar thermodynamic quantities were obtained by using Krupkowski method and Margules power series, comparatively. The phase diagram of the investigated system is also presented.