This paper describes the application of a methodology, which primarily involves low-cost voltammetry, to rapidly track the reactivity (i.e. surfactant activity, SA) of dissolved organic carbon (DOC) ...in aquatic systems. The approach is based on the quantitative measurement of total surface activity (expressed as Triton-X-100 equivalent) of adsorbing organic compounds (AOCs) of amphiphilic and/or hydrophobic nature at the mercury electrode/electrolyte interface in natural water samples using phase-sensitive (out-of-phase) alternating current voltammetry (PSACV). The SA results were normalized to the DOC content. A graphical representation of DOC-normalized SA for different water systems allows a rough characterization and comparison of the DOC type at different scales (spatial, seasonal, temporal short- and long-term) and in extreme natural events such as different hydrological, meteorological, biological, and physical processes. The main idea is to demonstrate the capabilities of PSACV in the study of DOC in water systems. The presented methodology could be used in future research and monitoring studies, as PSACV is the only practical method available for the determination of surface active DOC in natural waters.
In the area of the North Croatian Basin, as the south-western part of the Pannonian Basin System, a lake that was characterized by mainly dolomite deposition evolved in the late Early Miocene. The ...dolomites precipitated directly from the water body, and are associated with tuffites and marls, together with minerals such as analcime, hydrous Ca-bearing magnesium carbonate, and natrolite. This indicates deposition in a shallow, hydrologically closed lake of highly alkaline waters controlled by an arid climate in the first stage of its evolution. The second evolutionary stage is represented by the intercalation of sandstones as a result of gravity flows, and dolomites that reflect changes of hydrologically open and closed lacustrine environments controlled by the frequent alternation of humid and arid climates. The third stage, that probably commenced in the Middle Miocene, indicates the formation of a long-lived, hydrologically mostly open lake, characterized by deposition of siliciclastics by gravity flows. The whole lacustrine depositional sequence coincides with the Miocene Climatic Optimum generally characterized by hot and warm, and humid climates. However, the evolution of the closed lake that is correlative with similar lakes in northern Bosnia and central Serbia, indicates the existence of an arid zone in the region that was confined by areas characterized by a more humid climate in the late Early Miocene.
•Transition from closed to open lake is reflected by lithological change.•Closed lake deposits are analcime-bearing.•Evolution of the closed lake indicates arid climate in Miocene Climatic Optimum.•Region characterized by arid climate in Early Miocene is defined.
Deposits of dimension stone (hereinafter: DS) are mostly of heterogeneous composition and non-uniform properties. For the purpose of exploring the DS deposit, it is necessary to perform certain ...mining work in order to collect data for the determination of: existence, position and shape of the bed, quantity and quality, and the conditions for exploitation of DS. The position and shape of the deposit have a crucial influence on DS exploitation conditions. Discontinuities of different positions, dimensions and shapes were formed as a result of dynamic and chemical processes in the rocks. The exploitation of DS from the deposit is performed by obtaining as geometrically regular and as large in size blocks as possible. The DS exploitation should be harmonized with the position and shape of the deposit as well as discontinuities for the purpose of obtaining the highest possible exploitation of stone. However, a special requirement of construction is to obtain the DS, primarily of uniform appearance and other properties. Therefore, it is necessary to optimize mining works for the purpose of obtaining and installing DS of a uniform appearance, as described and shown on several examples in this paper.
The successful exploration of dimension stone mainly depends on the quality, size, and shape of extractable blocks of dimension stone. The investigated area is in the Pelješac Peninsula (Croatia), in ...the External Dinarides orogeny, built from thick carbonate succession, characterized by relatively small deposits of high-quality dimension stone. These conditions demand challenging geological investigations in the “pre-quarry” phase to find optimal quarry location. The size and shape of dimension stone blocks are mainly controlled by fracture pattern systems. In the rugged, covered terrains, it is very hard to obtain a satisfactory amount of fracture data from the surface, so it is necessary to collect them from the underground. Borehole camera technology can visualize the inner part of the rock mass and measure the fracture characteristics. The main conclusions are as follows: (1) the digital borehole camera technology provides a quick, effective, and low-cost geological survey of fractured rock mass; (2) statistical fracture distribution parameters, P10, fracture spacing, Volumetric Joint Count (Jv) based on borehole wall survey can reflect the integrity of rock mass, providing a solid decision-making base for further investment plans and dimension stone excavation method.
The objective of this paper is the study of the life cycle inventory (LCI) for underground mining of small, clustered deposits of Dinaric Alps-type bauxites, mined in the mountains near Jajce, a town ...in Bosnia and Herzegovina, in the period 2010-2020. Modelling of the life cycle inventory was done based on the company’s internal reports and project documentation for a variant of the sublevel caving method that involves drilling and blasting. Four mines, located on three exploitation fields, were found in different phases of mine life, different levels of tectonic disturbances and different types of energy: diesel, electricity, and compressed air. The main results of this study are the inventory of underground bauxite exploitation made based on long-term data, the life cycle of one bauxite deposit, and the emission factors from blasting. Underground mining in this case proved to be energy intensive: an average of 52-92 MJ/t was required (as opposed to 37 MJ/t for surface bauxite exploitation in Italy). At the same time, underground bauxite exploitation caused only 5.6-6.4% of the transformation of natural land that is above the mines and deposits. The operations relying on diesel fuel caused local emissions in the air and underground. The operation relying on electricity for DC locomotive and generation of the compressed air were without local emission into the air, although energy efficiency was probably reduced using compressed air as mechanical energy. At the state level, the impact depends on the country’s energy mix, which is still quite dependent on fossil fuels. Engineering estimates of blasting emissions indicated detonators and ammonium nitrate explosives as a potentially important source of environmental impact. The mining industry would significantly benefit from cleaner energy in electricity generation (the energy sector) in Bosnia and Herzegovina. The path of air emissions in the underground system, especially lead and nitrogen compounds, needs to be further explored.
This paper presents a new approach to exploring bauxite deposits from underground mining works in the bauxite-bearing mines of Bešpelj near Jajce in Bosnia and Herzegovina. In the area under ...consideration, bauxite deposits have been investigated and exploited for over 60 years. Despite the high degree of exploration in the geologically complicated structures of Bešpelj, there are numerous unexplored reserves. Up to now, they have been mainly investigated by drilling from the surface into the borehole network as dictated by legal geological regulations. Due to the increase in depths on which deposits are located and complex structural relationships, such research has become more expensive and less effective. From a geological point of view, the bauxite deposits have developed in the horizontal position. However, long-lasting geological evolution from the Upper Cretaceous to the present, has brought deposits in very different structural positions. That is why we find them in an inclined position, in subvertical and vertical, and often in an overturned position. For further research to become rational and efficient, a new approach of study from underground mining works was developed that will serve for study and then for the exploitation of bauxite deposits.
In this paper we present and elaborate one example when bauxite was the main target of investigation. During reprocessing and reinterpreting original input data from locality “Crvene stijene” near ...Jajce in Bosnia and Herzegovina, it was established that bauxite hanging wall and footwall rocks in fact present even more valuable mineral resources, dimension stone. This paper presents results of reprocessing and reinterpretation of original data with focus not only on primary resource, but on resources that are developed in footwall and hanging wall. Final goal of the research was to optimize the ratio between research and exploration cost and total profit by exploration of all available mineral resources in the area. For that purpose, new method of bauxite (primary resource) and associated deposits is developed and named “integrated approach”. Integrated, joint evaluation of bauxite and associated deposits (dimension stone), would give far greater significance to whole area. Finally, with this new method, the ratio between overall profit and cost will be maximized.
In this paper we present and elaborate one research example when bauxite was the main target of the investigation. During reprocessing and reinterpretation of the original data from the "Crvene ...stijene" locality near Jajce in Bosnia and Herzegovina, it was established that bauxite hanging wall and footwall rocks in fact represent an even more valuable mineral resource, as "dimension stone". The final goal of the research was to optimize the ratio between research and exploration costs and total profit by exploration of all available mineral resources in the area. For that purpose, a new research evaluation method encompassing both bauxite (primary resource) and associated deposits was developed and named the "integrated approach". Integrated, joint evaluation of bauxite and associated deposits (dimension stone), gives a far greater economic significance to whole area. Finally, with this new method, the ratio between overall profit and cost will be optimized which results in significant increase in profit because all available deposits are considered for exploitation. Also this method can be applied on abandoned mining sites if there is some secondary profitable mineral deposit in the mine area.
Mineral raw material transport directly affects a product's unit price and exhaust gases amounts. Transportation length is proportional to raw material price; its low price enables short ...transportation distances only. Taking into account stone aggregates delivered to Zagreb, the consequence of exploitation fields closure in the Zagreb area, particularly within the Medvednica Nature Park, we tried to answer the question of the impact of transport distances on the greenhouse gas emissions. Certain models will present environmental impact of the stone aggregate transportation and of nearby city quarries. The generally accepted public opinion on the closure of nearby city quarries as the best solution to environmental pollution will have to be reviewed. Mining works are predestined by mineral resources sites and limited by real possibilities and intentions of the community, therefore the experts, i.e. miners, geologists and other geoscientists, should be actively involved in spatial planning. During the years of intensive construction, millions of tons have been delivered from distances up to 100 km. The question arises whether some more rational solutions could be generated by more appropriate spatial planning?
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