Faculty of Mining, Geology and Petroleum Engineering Repository
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CEEPUS mreža CIII-RS-0038: prepoznavanje izazova u obrazovanju geoloških struka u jugoistočnoj Europi i moguća rješenja
No full textGeological education at South-Eastern European universities is developed under the CEEPUS CIII-RS-0038 network (Earth-Science Studies in Central and South-Eastern Europe – EURO Geo-Sci), which includes participating unites from eleven countries: Albania, Austria, Bosnia and Herzegovina, Croatia, Czech Republic, Hungary, Poland, Romania, Serbia, Slovakia and Slovenia. For long 24 years, EURO Geo-Sci continuously promotes sharing of knowledge and know-how via multilevel activities: student mobility, engagement of visiting peer-experts, joint supervision Master and PhD thesis, reinforcing geosciences educational infrastructure of the participating institutions. The network covers wide spectrum of geological disciplines including both fundamental (regional geology, mineralogy, crystallography, geochemistry, petrology, paleontology, structural geology etc) and applied disciplines (e.g. mineral resources, engineering geology, hydrogeology and geophysics). In the past 24 years more than 1500 individuals used the network through student and teacher mobilities, joint supervision master and PhD projects (successfully defended more than 20) as well as field excursions. During such a long period, the network is also continuously facing with many internal and external challenges. Internal challenges are related to low-funded, classical and sometimes outdated curricula of some programmes, lack of innovative content and teaching diversity brought by visiting experts and hands-on practical experience for peer academicians as well as for the students. External challenges are related to declining demographic trends and regional brain drain leading to decreasing in number of students, pandemic, unstable political situation (wars) as well as negative public perception of the geology (and mining) sector due to environmental and political activism. Thanks to flexibility of the network and dedicated engagement of the local coordinators, the network responds appropriately to the challenges involving new courses, networking with current scientific projects, cooperation with industry and serving the society in solving problems concerning pollution, water resources, land sliding, earthquakes, mineral deposits and many others. For more details about EURO Geo-Sci the following publications are recommended: ŠARIĆ (2022), ŠARIĆ et al. (2022), ŠARIĆ & IONESCU (2018), as well as the network’s website: https://ceepus.rgf.bg.ac.rs/, facebook page: Ceepus.RS0038 and instagram page: ceepus. rs0038.euro_geosci
Petrografske, mineraloške i kemijske karakteristike boksita iz ležišta u Posušju, Bosna i Hercegovina – AGEMERA projekt istraživanja
No full textThe exploitation of bauxite in the wider area of Posušje in Bosnia and Herzegovina has been known since the first half of the 20th century, and to date more than 1100 deposits or occurrences of various sizes and structures have been discovered. Bauxite deposits of Posušje represent typical karst bauxites, formed during the emersion phase between Upper Cretaceous rudist limestones in the footwall and various carbonate and clastic rocks of Paleocene/ Eocene and Oligocene ages in the hanging wall. The most intensive mineralogical and geochemical bauxite research in these areas was carried out during the 70s and 80s. Afterwards, despite numerous newly discovered deposits, no petrographic, mineralogical and geochemical analysis on the bauxites has been published. The present study is focused on recently discovered bauxite deposits in Posušje and their petrographic and mineralogical description. The bauxites show ooidic to pelitomorphic, but in places also clastic textures. Micro-ooids and spheroids are mostly smaller than 0.1 mm, and in places fragments of the former ooid can be found. In some bauxites, pebbles of resedimented bauxite prevail, mostly larger than 2 mm but sometimes larger than 1 cm, which define their conglomerate texture. Gibbsite and boehmite are the main Al-bearing minerals of the bauxites, and diaspore has not been observed. The ratio of gibbsite to boehmite varies between deposits, and in some deposits boehmite is the only aluminium phase present. Where present, the gibbsite is developed into relatively large hypidiomorphic crystals larger than 0.25 mm, with clearly defined polysynthetic lamellae. Hematite is the dominant Fe-phase in all deposits. Although rarely, goethite-rich bauxites can be found in the form of isolated layers, with just traces or no hematite. Zircon, apatite and calcite are minor and accessory minerals, and X-ray analysis indicated significant amounts of anatase and rutile. Kaolinite was detected in only one sample. Chemical analyses indicate a negative correlation of Al and Fe content. The Al2O3 content ranges from 53.4 to 63.9 wt.%, and Fe2O3 from 22.5 to 35.2 wt.%. The SiO2 and TiO2 content varies from 1.6 to 5.6 wt.% and 3.5 to 4.6 wt.%, respectively. The chemical composition of the analysed samples defines them as ferrous bauxites. A change in the chemical composition was observed in relation to the footwall distance. The relatively high content of Zn (up to 627 ppm) gradually decreases towards host carbonates of the footwall, and a similar trend is observed in the Fe, Cr and Zr content, while Al, P, Ca and Ti, on the other hand, increase closer to the footwall. Mineralogical, petrological and chemical studies of the recently opened bauxite mines in Posušje revels heterogenic properties and indicate a complex genesis of the deposits, with possibly diverse source material
Geneza i epigenetski razvoj boksita Minjere, Hrvatska, Istra
No full textPyritisation of bauxites occurs as a result of their epigenetic reduction during the formation of swampy environments in the bauxite cover during the initial phase of the transgression, which commonly follows the formation of the bauxite. The Minjera bauxites, which formed during the terrestrial phase which lasted between the Late Cenomanian/ Late Santonian and Early Eocene, were pyritised. The epigenetic pyritisation of these bauxites was related to the transgression that followed their formation, which led to the formation of ponds and swamps in the paleo-depressions in the karstified terrain, such as the sinkholes and canyons filled with the bauxite. Therefore, all of the Minjera bauxite bodies are covered by Lower Eocene Liburnian beds formed in such environments. The Minjera bauxites have been mined in the past, but only the pyrite-containing bauxite was used in the production of alum and vitriol, while the red bauxite was left in the tailing heaps in the area. Pyritised bauxite samples from two Minjera bauxite bodies (D-1 and D-15) were collected, with the aim to reconstruct their genesis and the processes which led to their formation and subsequent pyritisation. Two main types of bauxites, the grey bauxite and the pyritised bauxite, were distinguished based on their mineralogy, geochemistry as well as their structure and texture. The grey bauxite contains high amounts of kaolinite and moderate to high amounts of diaspore, while containing no or little böehmite. Iron sulphides, represented mainly by pyrite and sporadically by marcasite, are generally present in very low amounts in this type of bauxite and appear as veinlets and crystal clusters in the matrix and bauxite clasts and as replacements of iron oxide rich laminae in ooids. This type of bauxite is also enriched in bases and large ion lithophile elements compared to pyritised bauxite, which is likely related to lower leaching intensity. Pyritised bauxite contains high amounts of böehmite and iron sulphides, while containing very little to moderate amounts of kaolinite, and almost no diaspore. Iron sulphides appear in these samples in many different morphologies and textures. They replace the iron oxide-rich laminae within the ooids and the fine-grained matrix between the bauxite clasts and ooids. In samples where the matrix was not completely pyritised, the pyritisation started from many crystallisation centres, from which iron sulphides grew outward, either in the forms of framboids or rosettes composed of needle shaped crystals. Iron sulphides in these samples commonly crystallize along the fractures, which is also seen on a large scale, in the form of centimetre-thick veins of iron sulphides parallel with the boundary between the bedrock and the bauxite. Both bauxites are enriched in heavy REEs, and display a slight negative cerium anomaly, which indicates the influence of marine porewater. Different textures and morphologies of iron sulphides suggest variations in the saturation with iron and sulphur and are probably linked with the sea-level variations during the initial stages of the transgression, which could have affected the production of organic matter in swampy environments that developed in the cover of the bauxite during this stage. The ingression of marine porewater was most likely the source of sulphur, which was derived from the microbial reduction of sulphur in the organic matter-rich environment. The pyritisation appears to have affected each bauxite deposit differently, since the grey bauxite is almost exclusively found in the D-15 deposit, while the pyritised bauxite is found only in the D-1 deposit. Besides their distinct epigenetic evolution, this also suggests that bauxites of different grades formed contemporaneously in the area, as the D-15 body is composed mainly from highly kaolinitic grey bauxite and the D-1 body from the highly böehmitic pyritised bauxite. This is probably related to different morphologies of the two bauxite bodies, as the D-1 body is much larger and steeper (> 20 m) than the D-15 bauxite body (< 5 m). The differences in their morphologies likely developed as a consequence of their different palaeotopographical positions, which led to different rates of chemical weathering between the two bauxite bodies
Glauconite formation in a palaeosol as an indicator of the incipient sea-level rise: case study of the Zlatni rt, Istria, Croatia
No full textGlauconite is usually found as a replacement of bioclasts and faecal pellets through neoformation and replacement of iron rich smectite in deepwater environments on the shelf-slope break. In the last two decades the formation of glauconite in shallow water environments was progressively recognized and utilized in palaeoenvironmental reconstructions. The Lower Kimmeridgian to Late Tithonian Zlatni rt (ZR) clay is one of the examples of glauconite formation in shallow water environment and a rare example of glauconite formation from a palaeosol. The ZR clay occurrence represents a decimetre thick horizon of grey clay embedding the black pebbles. The clay is also present as infills in the karstified bedrock, in which the glauconite is present within the contact zone of the clay and bedrock. The clay is primarily composed from mixed-layered illite–smectite, 2M1 illite, kaolinite, vermiculite, pyrite, marcasite and titanium oxides. The clay itself can be identified as a palaeosol which formed in contact with the marine environment, indicated by the high Sr/Ba ratios and enrichment of heavy rare earth elements and a slight negative cerium anomaly. The presence of glauconite was confirmed by SEM-EDS, XRPD and FTIR. The glauconite formed mainly through the fixation of potassium and iron into illite and illite–smectite, but there is also strong evidence of its neoformation through bacterially mediated dissolution of present phyllosilicates. The source of iron was most likely terrigenous, as there is evidence for a ferralitic input through the presence of kaolinite in the ZR clay. Glauconite is also present in a more reduced form and as a more oxidized form, which display an alternation with pyrite in veins. This reflects the oscillations in the redox potential during glauconite formation, which can be linked to the variations in water column depth during the initial stages of the transgression. The final drowning of the ZR clay is recorded with the precipitation of coarse euhedral pyrite, during which the deposition of lagoonal Upper Tithonian Kirmenjak limestones had started. This work has been fully supported by Croatian Science Foundation under the project IP-2019-04-8054 – Wian- Lab (Western Istrian Anticline as an Ideal Natural Laboratory for the Study of the Regional Unconformities in Carbonate Rocks)
Kartiranje tala panonskog dijela Hrvatske prema Unified Soil Classification System upotrebom multinomne logističke regresije i interpolacije inverzijom udaljenosti
No full textUnified Soil Classification System (USCS) osnova je brojnih metoda za istraživanje prohodnosti tla za vozila. Budući da podatci o USCS-u nisu uvijek dostupni, koriste se razni drugi izvori i metode za korelaciju i predviđanje USCS grupe tla. U ovome radu opisane su dvije metode korištene u svrhu kartiranja hrvatskog dijela panonskog bazena prema USCS-u do dubine tla od 50 cm. U prvoj metodi ispitana je mogućnost prijenosa 308 uzoraka tla prema sustavu klasifikacije International Soil Science Society (ISSS) u USCS. Rezultati su pokazali da nije moguće izravno transformirati podatke ISSS klasifikacije u USCS. U drugoj metodi korišteno je 414 USCS profila u analizi težišnih faktora u prostornoj analizi s ponderiranjem obrnute udaljenosti. Analizom su obuhvaćeni slojevi dominantnih i asocijativnih jedinica tala Osnovne pedološke karte Hrvatske (BSM), Osnovne geološke karte Hrvatske (GM), dreniranost tla i slivna područja. Dobivene ponderirane težine bile su: BSM 47,12 %, slivno područje 27,12 %, GM 17,67 % i dreniranost tla 8 %. Rezultati su pokazali da je panonski dio Hrvatske prekriven sitnozrnatim tlima, pri čemu je glinom prekriveno gotovo cijelo područje, dok prahovi dominiraju u zapadnim i sjeverozapadnim dijelovima panonskog bazena Hrvatske.The Unified Soil Classification System (USCS) is the basis for numerous methods for soil trafficability research. Since USCS data are not always available, various other data and methods are used to correlate and predict the USCS soil group. This paper describes two methods used for the purpose of mapping the Croatian part of the Pannonian Basin (PB) according to the USCS to a depth of 50 cm. In the first method, the possibility of the transfer of 308 profile samples according to the International Soil Science Society (ISSS) classification system into the USCS was examined. The results show that it is impossible to directly transform ISSS data into the USCS. In the second method 414 USCS profiles were used to analyse the weights of factors in the spatial analysis with inverse distance weighting (IDW). The analysis included layers of dominant and associated soil units of the Basic Soil Map of Croatia (BSM), Geological Map of Croatia (GM), drainage and catchment areas. The obtained weights were as follows: BSM 47.12%, catchment area 27.12%, GM 17.67% and drainage 8%. The results showed that PB in Croatia is covered with fine-grained soils, with clay covering almost the entire area and silt dominating in the western and north-western parts of the country
Development of a reference device for the calibration of optical one-shot time-interval measurements
No full textThis paper presents the development of a device that creates two or more light pulses with a precision time delay in a range from microseconds to several seconds and for the purpose of the calibration of velocity of detonation (VOD) measurement instruments. The device was assembled, programmed, and tested for functionality. Measurements were conducted using a reference counter. First, a precision OCXO (oven-controlled crystal oscillator) was used as a clock source. For verification of programmed subroutines, a counter oscillator output port was used as a source of clock signal for the microcontroller. This enabled the cancellation of possible oscillator errors. The signal had to be converted from an AC sine signal to a signal with positive values only using a clamper circuit. By the proposed solution, a calculable standard of time delay between two light pulses was achieved. According to the obtained results, this device can be used to calibrate field measurement devices for VOD measurements in explosives or some other use where the measurement device records the time interval between multiple light pulses. This enables more confidence in measurement results, faster recognition of instrument drift and increases the quality of measurement
Application software developed for the determination of expansion volume in clay soil generated by the detonation of an explosive charge
No full textBlasting in clay soil in the field of anchoring and foundation of objects and structures has its benefits in construction and geotechnical practice. The foundations of the method lay in the fact that a shock wave is generated when the explosive charge is detonated. The shock wave, with high pressure at the wavefront, causes the natural structure of the clay soil to be destroyed, and a spherical expansion in the clay mass is formed. The presented research is focused on determining the shape and volume of the resulting expansion in test blasts performed with several types of explosives. An application named Borehole was developed to determine the resulting spherical expansion formed after the detonation of an explosive charge with the integration of the GNSS method of measurement, depth camera, and laser. The application Borehole calculates expansion volume based on the coordinates obtained with the GNSS and the laser-obtained distance of the formed expansion and provides a graphical interpretation in 2D and 3D views. Additionally, when developing the application Borehole, compatibility with CAD tools was considered, primarily for better verification and a more detailed graphical interpretation of 3D views. The developed method allows for simple determination of the volume and dimension of the spherical expansion in clay soil with acceptable accuracy for the design and building of geotechnical structures constructed above and underground
Interventions in nature and areas of bird conservation: recommendations for the design of extraction of mineral raw materials in Zadar County : master's thesis
No full textZaštita klime, bioraznolikosti i okoliša u cjelini, resursna učinkovitost te sigurnost opskrbe resursima neki su od najvažnijih izazova današnjice. Nova strategija za postizanje održivosti gospodarstva EU-a, „Zeleni plan“ predlaže okvirne mjere za pretvaranje klimatskih i ekoloških izazova u prilike u svim područjima politike i osiguravanjem pravedne i uključive tranzicije gospodarstva kojom će se unaprjeđivati učinkovito iskorištavanje resursa prelaskom na čisto kružno gospodarstvo, zaustavljati klimatske promjene, obnavljati biološka raznolikost i smanjivati onečišćenje. Sektor rudarstva i vađenja ima važnu ulogu u tranziciji i postizanju ciljeva održivosti budući da su rudarski zahvati ujedno i zahvati u prirodi. Metode eksploatacije mineralnih sirovina u Republici Hrvatskoj se temelje ili na strojnom iskopu ili na bušenju i miniranju, a izvode se najčešće površinski, i rjeđe - podzemno. Najvažniji utjecaji na bioraznolikost uzrokovani su zauzećem i transformacijom prostora te uznemiravanjem uslijed prometa, prisutnosti ljudi i strojeva te buke i vibracija. U ovom radu razmatra se kako bi se izazovi povezani sa rudarskim zahvatima mogli pretvoriti u prilike za očuvanje i obnovu bioraznolikosti u područjima površinske eksploatacije mineralnih sirovina kao što su tehničko-građevni kamen, karbonatne mineralne sirovine za proizvodnju cementa, arhitektonsko-građevni kamen te boksit u Zadarskoj županiji. Zadarska županija zbog povoljne geologije i velikih rezervi mineralnih sirovina ima dugu rudarsku tradiciju, brojna eksploatacijska polja, no također u njoj se nalaze područja međunarodne i nacionalne zaštite prirode kao što su nacionalni park Paklenica, parkovi prirode Velebit, Telašćica i Vransko jezero u sklopu kojeg se nalazi i ornitološki rezervat, te europska ekološka mreža Natura 2000. Rad se fokusira na zaštitu ugroženih vrsta ptica. Najznačajniji zaključci i preporuke dionicima u prostornom planiranju i projektiranju eksploatacije mineralnih sirovina su: balansirati veličine površina pod eksploatacijom i pod biološkom obnovom, planirati i zaštititi dugoročnu održivost opskrbe mineralnim resursima, provoditi biološki monitoring istražnog prostora, te uklapati rezultate monitoringa istražnog prostora u idejni rudarski projekt.Protection of the climate, biodiversity and the environment as a whole, resource efficiency and security of resource supply are some of the most important challenges today. The new strategy for sustainability of the EU economy, European Green Deal, provides measures to turn climate and environmental challenges into opportunities in all policy areas to incur fair and inclusive transition to the resource efficient, clean and circular economy, to stop the climate change, restore biological diversity and reduce pollution. The mining and extraction sector has an important role in the transition and the achievement of sustainability goals. In the Republic of Croatia mining operations are based mainly on the surface extraction/open pit methods relying on mechanical excavation or drilling and blasting technology. The most important impacts on biodiversity from mining are caused by the occupation and transformation of space, the disturbance due to traffic, the presence of people and machines, noise and vibrations. This thesis considers how the challenges associated with mining operations could be turned into opportunities for the preservation and restoration of biodiversity in the areas of surface exploitation of mineral raw materials such as construction stone, carbonate mineral raw materials for the production of cement, dimension stone and bauxite in Zadar County. Due to its favorable geology and large reserves of mineral resources, the Zadar County has a long mining tradition, numerous exploitation fields, but it also has areas of international and national nature protection, such as the Paklenica National Park, the Velebit, Telašćica and Vrana Lake nature parks including ornithological reservation, and European ecological network Natura 2000. The thesis focuses on the protection of endangered bird species. The most significant conclusions and recommendations to stakeholders in spatial and mine planning and design are to balance the size of the surface under exploitation and under biological restoration, to plan and protect the long-term sustainability of the supply of mineral resources, to include biodiversity monitoring of the exploration area, and to incorporate the results of the bio-monitoring into the mining project
Visual approximation of strength of samples based on limestones from Istria : master's thesis
No full textU diplomskom radu na 96 uzoraka, šest varijeteta vapnenaca iz Istre provedeno je mikroskopsko određivanje značajki uzoraka, vizualno određivanje čvrstoće uzoraka i mjerenje brzine prolaska P – valova kroz uzorke. Koristeći determinirane stijenske značajke vapnenaca i vrijednosti brzina prolaska P – valova kroz uzorke, izračunata je jednoosna tlačna čvrstoća i napravljena je klasifikacija uzoraka. Uzorci su klasificirani prema IAEG (1979), ISRM (1981) i ISO (2003) klasifikacijama. Uzorci četiri od ispitanih šest varijeteta su ispravno klasificirani prema sve tri klasifikacije. S obzirom na dobivene rezultate, metoda se pokazala uspješnom za stijene, čija vrijednost jednoosne tlačne čvrstoće prelazi 100 MPa.In this thesis tests were conducted on 96 samples of 6 types of limestones from Istria. These tests included microscopical determination of sample characteristics, visual determination of rock strength and measurments of P – wave velocity travelling through samples. Determined characteristics of limestones and measured values of P – wave velocitiy, were used for calculation of uniaxial compressive strength. Using these calculated values, classification of samples was conducted. Samples were classified using IAEG (1979.) classification, ISRM (1981.) classification and ISO (2003.) classification. Four out of six types of limestone were classified correctly, according to all three classifications. Based on achieved results, method has proven sucessful for rocks, which have uniaxial compressive strength over 100 MPa
The influence of rock material properties on excavator productivity and optimal operating parameters : doctoral dissertation
No full textHidraulički bager jedan je od najčešće korištenih strojeva u rudarstvu te zbog toga postoji veliki interes istraživača za proučavanjem njegovoga učinka i optimizacije rada. Istraživanje u okviru ovog rada zasniva se na detaljnom proučavanju rada bagera u realnim uvjetima. Takva su istraživanja, prema dostupnoj literaturi, relativno skromna te postoji veliki prostor za napredak. Kako bi se pristupilo podatcima koji pružaju uvid u realni rad bagera potrebno je kontinuirano mjerenje produljenja i tlakova na hidrauličkim cilindrima. To je ostvareno pomoću specifičnoga mjernog sustava kojim se izvodi simultano mjerenje većeg broja parametara na bageru pri radu u realnim uvjetima. Izmjereni podatci obrađeni su pomoću računalnoga programa napisanoga u programskom jeziku Python. Pomoću standardnih kinematičkih i dinamičkih modela bagera dobivene su vrijednosti dinamičkih veličina rada (sila, snaga i utrošak energije pri kopanju) te geometrijskih veličina kopanja (kut upada zuba, duljina i površina reza). Terenska mjerenja izvedena su na pet različitih modela bagera te ukupno trinaest materijala. Laboratorijskim i terenskim ispitivanjima utvrđene su značajke materijala (granulacija, sadržaj vlage i nasipna gustoća). U radu je proračunat učinak kopanja koji predstavlja masu ili volumen iskopanog materijala u vremenu koje je bilo potrebno za izvođenje kopanja. U okviru statističke obrade podataka izvedene su višestruke regresijske analize utjecaja značajki materijala na dinamičke veličine rada bagera i geometriju kopanja. Regresijskom analizom također je prikazan utjecaj karakteristika materijala i geometrije kopanja na učinak. Utvrđeno je da granulometrijski sastav rastresitih materijala predstavlja najutjecajnije svojstvo na učinak kopanja, dok je duljina trajektorije kopanja najutjecajnija geometrijska veličina. Detaljnom analizom zasebnih ciklusa rada bagera utvrđena je razlika optimalne trajektorije kopanja u različitim materijalima. Predložena je klasifikacija učinka kopanja bagera u različitim materijalima. Također je predložen model za procjenu značajki materijala na temelju dinamičkih veličina rada bagera.The hydraulic excavator is one of the most commonly used machines in mining. Because of this, researchers have a great interest in studying its productivity and optimization of work. The research within this work is based on a detailed study of the operation of an excavator in real conditions. According to the available literature, such research is relatively modest and there is a lot of room for improvement. In order to access the data that provides insight into the real operation of the excavator, it is necessary to continuously measure the extension and pressures on the hydraulic cylinders. This is achieved by using a specific measuring system that can perform a simultaneous measurement of several parameters on the excavator during its work in real conditions. The measured data was processed using a computer program written in the Python programming language. Using standard kinematic and dynamic models of excavators, values of dynamic parameters of work (force, power, and energy consumption during digging) and geometric parameters of digging (tooth angle, length, and cutting area) were obtained. The field measurements were performed on 5 different machines and a total of 13 materials. Laboratory and field measurements determined the characteristics of the material (granulation, moisture content, and bulk density). In the paper, the productivity of digging was calculated, which represents the mass or volume of the excavated material in the time it took to perform the digging. In the frame of the statistical processing of data, multiple regression analyses have been performed on the influence of the characteristics of the material on the dynamic parameters of the excavator and the digging geometry. By regression analysis, the influence of the characteristics of the rocks and the geometry of digging on the productivity of digging are also shown. The size distribution has been found to be the most influential property of non-cohesive materials on the productivity of digging, while the length of the digging trajectory is the most influential geometric size. Through detailed analysis of the separate work cycles of the excavators, the difference in optimal digging trajectory in different materials has been determined. The classification of productivity of excavators digging in different materials is proposed. A model for assessing the characteristics of the materials based on the dynamic working parameters of the excavator is also proposed