Djordje Nikolic

The influence of the silicate slag composition on copper losses during smelting of the sulfide concentrates

This paper presents the results of multi-linear regression analysis (MLRA) of the slag composition (SiO2, FeO, Fe3O4, CaO, Al2O3) and the content of copper in the matte on resulting copper content in the slag during smelting of the sulfide concentrates in the reverberatory furnace. When comparing results obtained with MLRA model calculations with values measured at industrial level high degree of fitting is obtained (R2 = 0.974). This indicates that slag composition and content of copper in the matte influences the copper losses in the waste slag with the probability of 95 %.

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.

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.

Effect of the Slag Basicity on the Coefficient of Distribution Between Copper Matte and the Slag for Certain Metals

This paper presents the results of investigation of the effect of slag composition and the slag basicity, in the process of smelting of sulfide copper concentrate, on the distribution coefficient ( ) for the following elements: Cu, Bi, Co, Au, Ag, Zn, Pb, Ni, As, Sb, Se, and Te. The research was conducted under the industrial operating conditions of the copper smelter in Bor, Serbia. High values for the coefficient of determination (R 2 > 0.6) for the dependence on the slag composition were obtained, which presents a high degree of fitting. In the case of the dependence of on the slag basicity, obtained R 2 values were much lower, due to the much smaller statistical sample.

Episodes of extremely high concentrations of SO2 and particulate matter in the urban environment of Bor, Serbia.

This paper presents the extremely high concentrations of SO2 and particulate matter measured in the urban area of the town Bor (Serbia) during August 2011. Concentrations of SO2 above 125 μg m(-3) and concentrations of particulate matter above 200 μg m(-3) recorded over several days indicate significant risk to human health and the ecosystem in this region.

Multi-Criteria Decision Support System for Optimal Blending Process in Zinc Production

The formation of input batch zinc concentrates is one of the key processes on which the quality and efficiency of all subsequent operations during the production of zinc cathodes directly depends. The optimization of the formation of a mixed batch aims at making a selection between the zinc concentrates that have different contents of useful and harmful components and to determine their share in the optimal mix. A multi criteria optimization model, which can be a good support for the defined problem of determining the optimal mixture of zinc concentrates, was developed in this study. For an evaluation of this model, according to four different research scenarios, the PROMETHEE/GAIA methodology was used to rank the considered zinc concentrates and determine their optimal share in the mix batch. In addition, the determination of the significance of the criteria in the optimization model was performed by application of the subjective AHP approach and the objective entropic approach. The results of this study, which were obtained during an analysis of a real case from the practice of a zinc production facility, indicate that the choice and formation of the optimal mixture of concentrates directly depends on the subjective or objective type of assessment of the significance of several chemical components in the zinc concentrates, and on the market price of the considered concentrates.

Comparative study of hydraulic structures alternatives using promethee II complete ranking method

Hydraulic structures have a direct, strong and long-lasting impact on the economy and society in general. Providing the proper structural solution implies finding a balance between economic, environmental and social requirements while decisions taken are associated with serious and irreversible consequences. Optimization techniques play a key role in finding the right solution. In this paper, for a selected stretch of a river, PROMETHEE complete ranking method was employed for selecting the appropriate solution for river training works. This study goal is to determine the level of agreement and to test the sensitivity of the results obtained by two techniques ELECTRE simplified and PROMETHEE method - subjective and objective approach to determining the criterion weight. Findings confirm the justification of implementing both optimization techniques, particularly in the pre-feasibility studies. These techniques still have important implementation and development possibilities, although they have not yet been largely accepted by the engineering community.

Ranking of EU National Banking Systems Using Multi-Criteria Analysis in the Light of Brexit

In order to define and implement the most effective measures to overcome the difficulties of the post-crisis period, the policy-makers of ECB must identify not just main weaknesses of each banking system, but their strong points also. This requires the application of multi-criteria analysis, considering that policy-makers need to take into account a number of different aspects that, on the whole, indicate the quality of the banking system. Our aim is a comparative analysis of European banking systems right after the Brexit moment and within the framework of the tight new Basel III regulations. In this paper, we have ranked the banking systems of the 28 EU member states using multi-criteria analysis, specifically the PROMETHEE II method. The use of the PROMETHEE II method in combination with the entropy method offers a comprehensive insight into the banking system of each member state, given that the observed countries are ranked according to 9 conflicting criteria that are mostly used in banking system analysis. Our analysis shows that the banking systems in Central and Eastern Europe are the best performers, while the EMU’s developed banking systems such as the German, Italian, British, and French one are positioned among the last ranked. The Portuguese and Greek banking systems are, as expected, ranked in the last positions in our list. The obtained results also pointed out that the ECB should change its approach to the management and further development of a European Banking Union.