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Long-term planning for open pits for mining sulphide-oxide ores in order to achieve maximum profit

Krzanovic D., Conic V., Stevanovic D., Kolonja B., Vaduveskovic J.

Archives of Mining Sciences

2017

Vol. 62, no. 4

807--824

Profitable exploitation of mineralised material from the earth’s crust is a complex and difficult task that depends on a comprehensive planning process. Answering the question of how to plan production depends on the geometry of the deposit, as well as the concentration, distribution, and type of minerals in it. The complex nature of mineral deposits largely determines the method of exploitation and profitability of mining operations. In addition to unit operating costs and metal prices, the optimal recovery of and achievement of maximum profit from deposits of sulphide-oxide ores also depend, to a significant extent, on the level of technological recovery achieved in the ore processing procedure. Therefore, in defining a long-term development strategy for open pits, special attention must be paid to the selection of an optimal procedure for ore processing in order to achieve the main objective: maximising the Net Present Value (NPV). The effect of using two different processes, flotation processing and hydrometallurgical methods (bioleaching acid leaching), on determining the ultimate pit is shown in the case of the Kraku Bugaresku-Cementacija sulphide-oxide ore deposit in eastern Serbia. Analysis shows that the application of hydrometallurgical methods of processing sulphide-oxide ore achieved an increase in NPV of 20.42%.

Przynosząca zyski eksploatacja kopalin wydobywanych ze skorupy ziemskiej jest zadaniem złożonym i trudnym, wymagającym całościowego planowania. Aby określić w jaki sposób zaplanować prace wydobywcze, należy uwzględnić geometrię złoża, a także rozkład, koncentrację i rodzaj zawartych w złożu minerałów. Złożony charakter złóż minerałów w dużej mierze determinuje wybór metod wydobycia oraz poziom zysków. Obok jednostkowych kosztów produkcji oraz cen metali, optymalna eksploatacja złóż rud siarczkowych i osiągniecie maksymalnych zysków w dużej mierze zależą także od zastosowanych technologii uzyskiwania metalu z rud. Przy definiowaniu długoterminowej strategii wydobycia rud w kopalni odkrywkowej uwzględnić także należy wybór optymalnej metody obróbki rud w celu uzyskania założonego celu: maksymalizacji wartości bieżącej netto (NPV – Net Present Value). Wykorzystanie dwóch procesów: flotacji oraz metod hydro-metalurgicznych (bio-wypłukiwanie, ługowanie) przedstawiono dla rozważanego przypadku kopalni odkrywkowej rudy siarczkowej eksploatującej złoże w regionie Kraku-Bugaresku-Cementacija we wschodniej Serbii. Analizy wskazały, że zastosowanie metod hydro-metalurgicznych zapewnia wzrost wartości bieżącej netto o 20.42%.

Proposal of new monitoring network of water bodies of karst groundwater in Serbia

Poledica M., Stevanovic D.

Geology, Geophysics and Environment

2016

Vol. 42, no. 1

122--123

Groundwater resources play a dominant role in water supply in Serbia, and to manage them properly, an assessment of their quantitative and qualitative status must be given. The concept of quality groundwater management is the implementation of EU Water Framework Directive (WFD-2000/6/EC). In this, groundwater monitoring has the highest role, which should provide a comprehensive insight into the quantitative and qualitative characteristics of water in a particular area (Stevanović 2011). The research area in this case is karst landscapes of Serbia. The water bodies of karst groundwater have been identified in the Carpathian-Balkan Mountains of eastern Serbia and in the Dinaric area of western Serbia. Groundwaters of alluvial aquifers along the major rivers are systematically monitored, however, karst and artesian aquifers are not covered by the monitoring network. The current state of monitoring network in the karst of Serbia is, to say the least, unsatisfactory – only the spring of Mlava is observed by the Republic hydrometeorological service of Serbia. EU Water Framework Directive proposes water resource management at the level of river basins, so therefore, prior to network organization, the grouping of existing water bodies of karst groundwater was performed. The basic rule for grouping water bodies is that all bodies must belong to the same river basin and the groups provide reliable data for assessing the status of individual water bodies. Then topographical, geomorphological, hydrographic, geological and hydrogeological characteristics of the terrain were analyzed. According to Poledica (2015) and Stevanović (2015), 25 groups of water bodies in the areas of exploration have been singled out, 13 of them in western and 12 in eastern Serbia. For each group a representative monitoring network has been determined. 104 observation facilities have been selected in the domain of quantity and 53 facilities in the quality domain. This is the total number of observation points that are further sorted by priority. Including the economic factor, it is proposed to gradually develop monitoring networks. Beginning of observation will start in a period of 5 years from now, when observation facilities of first priority (springs of water supply) will be included. The observation facilities of second priority will be included in a period of 10 years from now and those of third priority will be included by 2035. Karst springs and purpose-built piezometers within the source where there are already wells for water supply provide the largest numbers of observation points. Also, hydrological stations are located on watercourses near karst springs where flows during the dry period of the year will be monitored. The final results are presented in the form of hydrogeological maps of Eastern and Western Serbia, which contain water bodies with observation points. These maps were made using the software package ArcGIS. On all facilities, it has been determined which parameters will continuously be monitored (content of observation) and how often (frequency of observation). The level of water will be observed continuously on the places where piezometers will be drilled. Discharge of springs will be observed each other day. Discharge regime of karst springs is studied enough only after many years of research. The reconstruction of monitoring network is suggested after six years. Microbiological and bacterial composition will be observed at least six times a year and other qualitative parameters at least four times a year. Spring discharges and level of groundwater belong to quantitative parameters. Dissolved oxygen, pH value, electrical conductivity, nitrates, turbidity and microbiological composition belong to qualitative parameters. It is very important to include all institutions that are the direct users of these resources, especially water supply system, industry and institutes for public health, and ensure the good cooperation and communication between them. studied enough only after many years of research. The reconstruction of monitoring network is suggested after six years. Microbiological and bacterial composition will be observed at least six times a year and other qualitative parameters at least four times a year. Spring discharges and level of groundwater belong to quantitative parameters. Dissolved oxygen, pH value, electrical conductivity, nitrates, turbidity and microbiological composition belong to qualitative parameters. It is very important to include all institutions that are the direct users of these resources, especially water supply system, industry and institutes for public health, and ensure the good cooperation and communication between them.