Journal of Mining and Metallurgy, Section A: Mining – vol. 60 A – 2024


Author(s): M. Banješević

doi: 10.5937/JMMA 2401001B

Abstract

This study reports on the stratigraphic characteristics of the main units and indicates the link between magmatism and mineralization in the Bor Metallogenetic Zone (BMZ) – the Timok Magmatic Complex (TMC). Existing data are supplemented by the latest different systematic long-term geological and stratigraphic surveys and new and contemporary mineral exploration methods. The TMC extends on a continental crust composed of different types of the Proterozoic to the Lower Cretaceous units and consists of the volcanic/magmatic, volcanogenic-sedimentary and sedimentary rock packages. Sedimentary processes and magmatism were almost continuous throughout the Late Cretaceous. The sedimentation lasted from the Albian-Cenomanian to the Maastrichtian. Magmatism occurred in at least two phases from the Upper Turonian to the Upper Campanian: I volcanic phase – V1 (90-82 Ma), II volcanic phase – V2 (83-78 Ma), with a steady decrease in age from east to west. Cu-Au porphyry mineralization occurs between 87-80 Ma. The major epithermal and porphyry mineralization is related to the V1 magmatic phase predominantly developed in the easternmost part of the BMZ

Key words: Bor Metallogenic Zone, Timok Magmatic Complex, stratigraphy, volcanism, age data, mineralization

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Author(s): M. Marić

doi: 10.5937/JMMA 2401011M

Abstract

The remains of ancient mining activities represent a significant part of Serbia’s archaeological sites in the mountain landscapes, which are not yet officially treated as cultural heritage. This type of assets poses a significant challenge for cultural heritage protection services, as it requires co-operation between experts for the protection of natural and cultural values and other stakeholders, which is not yet established. In addition, the concept of mining landscapes is not recognized in current legislation, which further complicates the legal protection of the remains of ancient mines, which are recognized by scholars as an essential segment in the interpretation of historical processes of significance, such as Roman imperialism in the Balkans. Against this background, the paper presents the decades of archaeological research at Kopaonik, which has led, among other aspects, to an attempt to establish a uniform practice of treating ancient mines, together with settlements and associated infrastructure, as an integral part of the mountain landscape, despite the absence of any legal regulation. The study examines the challenges associated with the formal-legal preservation of sites with historic mining, taking into account the possibility of permanent destruction. Finally, an outlook is given on the future of the protection of (pre)historic mines in Serbia as an important element of the country’s geocultural resources
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Key words: Kopaonik, antiquity, mining, geocultural heritage, legal regulations
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Author(s): V. Nikolić, M. Trumić, D. Tanikić, M. S. Trumić

doi: 10.5937/JMMA 2401023N

Abstract

The micronizing grinding of natural zeolite, of the clinoptilolite type, was investigated in a ring mill. The aim of the experiment was to determine the optimal grinding conditions to obtain a powder with appropriate physico-chemical and microstructural characteristics that would find its potential application as a binder and ion exchanger in structural composites. The analysis of specific size classes of zeolite e after micronization was performed by grinding kinetics.The research was carried out on previously prepared zeolite samples, on wider and narrower size classes (-3.35 + 0 mm; -3.35 + 2.36 mm; -2.36 + 1.18 mm; -1.18 + 0 mm) and different starting masses (50 g, 100 g, 200 g). Fine grinding was carried out at different time intervals (20 s, 45 s, 75 s, 120 s, 300 s, 900 s). A sieve analysis was performed on the grinding products, the content of the size class (-5 + 0) μm and the specific surface area of these products were determined. XRD analysis was performed on individual grinding products to take into account possible changes in the zeolite material itself. Based on the results obtained, an artificial neural network was developed and then compared with the experimental results. The artificial neural network models have achieved a satisfactory prediction accuracy (0.989 – 0.997) and can be considered accurate and very useful for the prediction of variable responses.

Key words: : zeolite, micronizing grinding, specific surface, artificial neural networks.

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Author(s): A. Peppas, C. Politi, E. Pantazakou, D. Skenderas

doi: 10.5937/JMMA 2401033P

Abstract

Froth flotation is the leading process for the selective separation of minerals and the beneficiation of ores. The principle of the method depends on the different wettability properties of the minerals, specifically on the hydrophobicity of the surfaces, which is either inherent or imparted to the minerals through reagents. Despite their widespread and long-standing use, they are considered highly hazardous and toxic and their decomposition poses a potential risk in terms of safety, health, and environmental impact. A new viable alternative, that promotes sustainable development, is the production and utilization of organosolv lignin nanoparticles. This study examines the environmental benefits of producing of lignin nanoparticles from birch wood as and partially replacing xanthate collectors with lignin nanoparticles for the treatment of 1 tonne of mined ore, subjected to flotation. In order to quantify the environmental impact, a life cycle assessment (LCA) was conducted for an Au flotation circuit. The analysis demonstrated that the introduction of organosolv lignin into the flotation process along with the reduction of sodium isopropyl xanthate (SIPX) resulted in the decrease of the environmental footprint and in particular the reduction of climate change and fossil fuel depletion by 16.79% and 3.8%, respectively.

Key words: : flotation, xanthate, lignin, life cycle assessment.
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Author(s): I. Vojinović, S. Stojadinović, I. Svrkota, M. Stojanović, D. Šabaz

doi: 10.5937/JMMA2401041V

Abstract

Seismic waves caused by blasting activities can be a source of damage to structures. The most common damage is the appearance of cracks or the widening of existing cracks. Structures are also affected by environmental factors. Depending on the conditions, temperature and humidity can cause a stronger reaction in the cracks than blasting. However, the effects of nonblasting factors last much longer than those of blasting, so the load gradually increases, allowing for an even and timely distribution of stress around the crack tip. On the other hand, blasting factors act over a short period of time, resulting in a rapid increase in the stress intensity factor at the crack tip and a faster release of stress energy. The FEM (finite element method) analysis of these impacts was conducted on a model in the ABAQUS CAE software. The results of the analysis show that the influence of blasting factors is significantly higher compared to the influence of non-blasting (environmental) factors. The strain energy and the stress intensity factor per unit time are much higher under the influence of blasting factors. The strain energy is 9.58 × 1010 times higher, and the stress intensity factor at the crack tip is 309583 times higher due to the dynamic load, observed over a period of 0.033 seconds.

Key words:  seismic waves, blasting, FEM method, ABAQUS CAE, crack, environmental factors.

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Author(s): T. Stanković, T. Radojević, I. Jovanović

doi: 10.5937/JMMA2401051S

Abstract

This paper describes the basic concept of multi-project management in the science and research organizations in Serbia and worldwide. A brief discussion was held on the sources of funding for these projects, and several proposed solutions to problems that may arise in the management of projects in the field of mining, were considered from the perspective of worldwide practice. An overview of completed projects in the field of mining and geology in the period from 2010 to 2023 is given using the example of a case study of a selected scientific and research organization, the Bor Mining and Metallurgy Institute, by type and number of projects and sources of funding. A brief analysis of the success of multi-project management in this institution was carried out. Considering the years of project development, it was determined it was found that the greatest success of multi-project management has been achieved in the last five years, which indicates the good business strategy of the Institute. The financing structure has shown that the largest number of projects in this institution, in the given period was financed by the private sector, i.e. the Chinese mining company Serbia Zijin Copper Bor (formerly RTB Bor).

Key words: multi-project management, financing, project, portfolio, case study

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