Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 4131 MINERALOGY, CHEMISTRY, AND DISTRIBUTION OF SELECTED TRACE ELEMENTS IN COAL AND SHALE FROM THE IBAR BASIN (SOUTH SERBIA) by Željana N. NOVKOVI] a , Nenad T. NIKOLI] b , Nevena A. ANDRI]-TOMAŠEVI] c , Violeta M. GAJI] d , Mercedes SUAREZ e , Emilia GARCIA-ROMERO f , Vladimir M. SIMI] d , and Dragana R. ŽIVOTI] d* aMMI Bor Mining and Metallurgy, Bor, Serbia bInstitute for Multidisciplinary Research, University of Belgrade, Belgrade, Serbia cInstitute of Applied Geosciences, Karlsruhe Institute of Technology, Karlsruhe, Germany dFaculty of Mining and Geology, University of Belgrade, Belgrade, Serbia eDepartment of Geology, University of Salamanca, Salamanca, Spain fDepartment of Mineralogy and Petrology, Complutense University of Madrid and Geosciences Institute (IGEO), Madrid, Spain Original scientific paper https://doi.org/10.2298/TSCI240405143N Coal samples from the Jarando, Tadenje, and Progorelica mines and organic-rich shale samples from the Piskanja boron deposit, all located in the Tertiary Ibar Basin, were studied using several methods such as transmitted light microscopy, X-ray powder diffraction (XRD), scanning electron microscopy with energy dis- persive X-ray spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), as well as inductively coupled plasma-mass spectrometry (ICP-MS) and X-ray fluorescence (XRF) spectrometry for evaluating their mineralogical and ge- ochemical compositions. The Ibar Basin hosts high-volatile bituminous coal de- posits and boron mineralisations. The mineralogical and geochemical data indi- cated that the main minerals in coals are quartz, pyrite, with a variable amount of clay (kaolinite, montmorillonite, illite), calcite and sulphates, while borates occur in low amounts. Framboidal pyrite is the main form of sulphur in coals. Clay and carbonate are often associated with macerals in mineral-bituminous groundmass, implying high ash yield and limited possibilities of coal cleaning treatment. Very high content of As, Co, Cu, Cr, and Ni was detected in high temperature coal ash (HTCA), especially in the Tadenje deposit. Contents of Mo, Sb, Pb, V, and Zn are slightly higher than the relevant Clarke values for bituminous coal ash. The shale samples from the Piskanja deposit mostly consist of a mixture of quartz, dolomite, and clay minerals (illite and chlorite) with variable amount of plagioclase, K-feld- spar, and mica. Lead, Zn, and Cu sulphides, gypsum, celestine, barite, rutile, and apatite were detected in low amounts. Key words: Ibar Basin, bituminous coal, shale, mineralogy, trace elements Introduction Coal is a very complex natural material consisting of a mixture of organic (macerals) and inorganic (minerals) components, gases and liquids at variable contents. The origin and the –––––––––––––– * Corresponding author, e-mail: dragana.zivotic@rgf.bg.ac.rs Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … 4132 THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 chemical properties of all components depend on the depositional environment, namely the conditions dominated in the paleomire, and the degree of chemical transformation the original sediment (peat) underwent, called coalification. The amount and the mode of occurrence of the inorganic components (minerals and elements) contained in coal [1], affect its quality and pro- vide valuable information on its behaviour during both mining and utilisation [2]. The determi- nation of mineral and chemical composition of coal is very important for an effective coal uti- lisation [3]. The Serbian bituminous coals are of minor economic importance due to their low quality and complex geological setting, the latter causing hard exploitation conditions. Today bituminous coal is mined only in the Ibar Basin (low-rank bituminous) and at Vrška Čuka (high- rank bituminous). The Ibar Basin is situated about 200 km south of Belgrade, in southern Serbia (fig. S1 in the Supplementary material). The basin is distinguished into several subbasins (Ušće, Tadenje, Jarando, Gradac) filled with Lower Miocene coal-bearing terrestrial sedimentary rocks [4, 5]. Bituminous coal is exploited in the Jarando and Tadenje underground mines and in the Progorelica open pit. Recent research confirmed the rank of the coal and shale of the Ibar Basin [6]. Previous exploration of the Ibar Basin focused on geology, stratigraphy, sedimentol- ogy, and coal properties, necessary for exploitation [7-11]. Mineralogical studies of coal and related sedimentary rocks, e.g. shales, were rarely conducted. The aim of this paper is to provide information on the mineralogical composition of Ibar coal and shale samples, as well as on the content of major and selected trace elements in high temperature coal ash. Geological setting The Ibar Basin is part of the Neogene Lake system placed in the internal part of the Dinarides [12, 13] which are formed during the collision of the European and Adriatic plates [14]. The Dinarides were affected by large-scale extension during Miocene [15, 16]. The Mio- cene extension led to exhumation of deep-seated core-complexes (e.g. Studenica and Kopaonik core-complex [15, 17]), as well as to the formation of extensional basins in the hanging wall, like Ibar Basin, [6]. The basement of the Ibar Basin consists of Palaeozoic chlorite schist; Triassic lime- stone, dolomite, marble, sandy marlstone, and marlstone; Jurassic harzburgite, serpentinite, gabbro, rodingite, and other rocks of the ophiolite melange; Oligocene/Miocene dacite-andesite lava flows; and Neogene quartzlatite/rhyodacite extrusions and pyroclastic rocks. Sedimentary rocks mainly of Neogene age consist of conglomerate, sandstone, marlstone, coal, carbona- ceous shale, shale, and claystone. The Lower Miocene Ibar Basin hosts mainly clastic to carbonate rocks including three to nine high-volatile bituminous coal seams. The deposition started in shallow lakes and mires at the earliest stage, later in alluvial and at the latest phase in the lacustrine environment [5]. Basin subsidence resulted in the formation of a 1500 m thick sedimentary sequence (based on geophysical exploration) [5]. The basin hosts bituminous coals, boron mineralization (borates and howlite), mag- nesite deposits and travertine, the latter is noticed during previous investigation [6]. The rela- tively high rank of Tertiary coals from the Ibar Basin is due to thermometamorphism, while the differences in maceral and geochemical composition of Tadenje coal were explained by rela- tively more oxic depositional environment [4]. The age of sediments is not well constrained. Based on sedimentary layer correlation from other intermontane basins in the Dinaridic Lake System, it could be inferred that the alluvial deposition started around 19-17 Ma (Megaannum) Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 4133 and lasted until 16-15 Ma when a typical lacustrine environment established. Combining geo- dynamical [17] and paleontological lines of evidence in the following discussion [6], 19 Ma was adopted as the age of the onset of sedimentation in the Ibar Basin. Vitrinite reflectance and apatite fission track data of the studied sedimentary rocks from the Piskanja (IBM-1) and Tadenje deposits imply post-depositional thermal overprint in the Ibar Basin. Thermal history models of the detrital apatite [6] revealed a heating episode prior to cooling that began at around 10 Ma. The heating episode started around 17 Ma and lasted until 10-8 Ma reaching maximum temperatures between 100-130 °C. Authors correlate this event with the domal uplift of the Studenica and Kopaonik core complex. The cooling episode is related to basin inversion and erosion. The apatite fission track data indicates local thermal perturbations, detected in the SE part of the Ibar Basin (Piskanja deposit) at around ~7.1 May, which may correspond to the youngest hydrothermal phase in the region. Samples and analytical methods Thirteen coal samples were collected through channel sampling from the Jarando, Tadenje, and Progorelica mines. Moreover, nine shale samples were picked up from the IBM- 1 core drilled in the Piskanja deposit (tab. S1 and fig. S1 in the Supplementary material). The samples represent different lithotypes and parts of the coal seams. The sedimentological examinations included several analytical procedures required for the optical determination of mineralogical-petrographical composition. About 30 g of each sample were poured into distilled water, slowly heated up to 40 oC for 30 minutes, and treated in an ultraviolet bath for 30 minutes. After cooling at room temperature, the sample was wet sieved using mesh with 0.063 mm openings. The fraction above 0.063 mm has been dried at room temperature and treated further. The next step is the split into two fractions using mesh with 0.6 mm openings, getting two fractions, one > 0.6 mm and the other < 0.6 mm. The > 0.6 mm fraction was used for thin section preparation. The < 0.6 mm fraction was subjected to heavy liquid separation using bromoform of specific mass 2.87 g/cm3. From the heavy frac- tion the magnetic minerals (magnetite, pyrrhotine) were removed by hand magnet. Optical tests were performed using binocular lens with integrated led light and digital camera Leica ЕЗ4D and on thin sections prepared in xylol [18] using the polarized microscope DMLSP connected to digital camera Leica DC 300. The sedimentological examinations were performed on sam- ples Jarando 1, Jarando 3, Tadenje 11, Tadenje 1, Tadenje 10B, Progorelica 3, Progorelica 1, Progorelica 10, and Progorelica 16. The XRD analysis was performed on coal samples (tab. S1) using a Rigaku SmartLab multipurpose X-ray diffractometer system in θ-θ geometry (the sample in horizontal position) in para-focusing Bragg-Brentano geometry using D/teX Ultra 250 strip detector in 1D XRF suppression mode with Kβ-filtered CuKα1,2 radiation source (U = 40 kV and I = 30 mA). The XRD patterns were collected in a continuous scanning mode in 2θ range 5-90º, with a step of 0.01º and data collection speed of 0.4° per minute. For shale samples from the Piskanja boron deposit, tab. S1, XRD was performed on: whole rock powdered, untreated oriented sample, and glycolated-oriented sample. The < 2 μm sample was obtained by suspension in water, decanta- tion and studied as oriented aggregates under ambient conditions and after solvation with eth- ylene glycol. Treated samples were studied with a step velocity of 0.05º every 3 seconds, from 2º to 65º in the case of the powdered whole rock and from 2º to 15º in the different oriented aggregates, with a step velocity of 0.05º each second. A Siemens D-500 XRD diffractometer with a CuKα radiation and a graphite monochromator was used. The crystal phase identification Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … 4134 THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 of all samples was performed in dedicated RIGAKU PDXL 2.0 software (with implemented ICCD PDF-2 2016 database). The FTIR spectra of the thirteen powdered coal samples, tab. S1, were recorded using a Perkin Elmer Spectrum Two equipped with the Universal ATR accessory. The spectrum of each powder sample was recorded in the mid-infrared range 4000-400 cm−1 with 20 scans and a spectral resolution of 4 cm−1. Baseline correction and band position determination were per- formed using the SPECTRAGRYPH software [19]. The band assignment was performed through comparison with the reported data on analogous material. The mineral composition of selected coal and shale samples, tab. S1, was investigated using a JEOL JSM-6610LV SEM (30 kV accelerating voltage) equipped with an energy-dis- persive X-ray spectrometer (SEM-EDS; X-Max Large Area Analytical Silicon Drift connected with INCAEnergy 350 Microanalysis System). Polished blocks of selected samples prepared according to standard procedure [20], were coated with a thin gold film for a higher quality of secondary electron image for SEM and EDX examination. The contents of major elements in shale samples were determined by XRF, while these of trace elements were determined by ICP-MS. Major and trace elements of coal ash samples were analysed by inductively coupled plasma – atomic emission spectrometry (ICP-AES). The XRF analysis was performed on RIGAKU Super Mini 200 XRF analyzer. Dried samples have been heated at 1000 °C. After cooling 2.5 g of each sample and 6 g of solvent made of Li- tetraborate and Li-metaborate (3:1), were homogenised and furnaced. The contents of minor elements in the shale samples were performed by ICP-MS analysis on Agilent 7700 following the procedures outlined by ASTM D6357-21a [21] standard. Major and minor elements in coal ash samples were determined by Spectro Ciros ICM-AES following the procedures outlined by ASTM D6349-21 [22] standard. For digestion, 0.2-0.5 g of powdered ( < 150 µm) ash sample was weighed into a 100 mg or 200 mg Teflon beaker. About 20 mL of aqua regia and 20 mL of concentrated HCl were added to the beaker. The beaker was heated to 130 °C to 150 °C. After the solution evaporated the beaker was removed and cooled to room temperature. Then 1 mL of concentrated HNO3 and 20 mL of H2O were added to the beaker and heated at 90 °C to 100 °C. The solution was cooled at room temperature and diluted with water. Results Mineralogy Sedimentology The heavy fraction of coal from the Jarando Basin consists of magnetite, sulphides, rounded aggregate grains, rock fragments, and coal fragments with sulphides, fig. 1. In the Jarando 1 sample, fragments of black coal with small radial minerals, probably borates, were separated. Pure minerals such as garnet and tourmaline, are rarely present. The light fraction dominantly consists of coal fragments. Inorganic constituents are represented by quartz or quartzite, rock fragments, borates, and rare feldspar grains. Magnetite, rare sulphides and coal fragments with sulphides, as well as rock frag- ments, were determined in the heavy fraction of coal from the Tadenje deposit. In the magnetic fraction, individual grains of rock/mineral fragments being heavily impregnated with small magnetite crystals and borates with a specific density higher than 2.87 g/cm3, were separated. Sulphide aggregates are in association with borates in radial forms, fig. 1(a). Fragments of marly rocks with borate laminae are more common here. The heavy fraction very rarely con- tains garnets, rutile, and dolomite. The light fraction consists mainly of coal fragments. There Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 4135 are also fragments of rocks with borates in the form of thin laminae or radial minerals. Other constituents in the light fraction are calcite/dolomite aggregate grains and rarely, quartz and feldspars. Figure 1. Photomicrographs of (a) the heavy fraction with magnetite, rock fragments and borates in Progorelica deposit and (b) the light fraction with coal fragments, borates, and quartz in Jarando deposit (the Ibar Basin). Photomicrographs were taken under reflected white light In the Progorelica deposit magnetite, rarely sulphides and coal fragments with sul- phides and borates, as well as fragments of felsic volcanic and fine grained sedimentary rock, are included in the heavy fraction. Hornblende, siderite, garnet, rock fragments, and tourmaline also occur in small amounts. The light fraction is mainly made up of coal fragments. There are also fragments of marly and dolomitic claystone with borates in the form of thin laminae or radial minerals. Other constituents in the light fraction are calcite/dolomite aggregate grains and rarely, quartz and feldspars. The X-ray diffraction analysis The XRD analysis proved that the mineral matter in the Jarando and Progorelica coals mainly consists of quartz, tab. 1 and fig. 2, with variable contents of kaolinite, montmorillonite, illite, and pyrite. The most abundant minerals in the Tadenje Seam-3 coal are quartz and pyrite, while kaolinite, calcite, gypsum, szomolnokite [FeSO4·(H2O)]/kieserite [MgSO4·(H2O)], mont- morillonite and illite are less abundant. Calcite is the most abundant mineral in the lower part of coal Seam 6 in Tadenje deposit with variable amounts of pyrite, quartz, kaolinite, and szomolnokite/kieserite. Illite and interstratified smectite-chlorite/vermiculite are less abundant. Analcime was observed in low amount only in Tadenje 1 sample. Quartz was identified as the most dominant phase in shales from Piskanja boron de- posit, tab. 1, fig. 2. Dolomite was observed in IBM-1/2, showing very low intensity peak in IBM-1/4. Traces of ankerite were detected only in sample IMB-1/2. Illite and/or mica, and chlorite occur in all samples. The XRD patterns of several shale samples in untreated, oriented and glycolated samples indicate the presence of the interstratified swelling + non-swelling com- ponents in mixed-layered clays, either as regularly interstratified smectite-chlorite or smectite- vermiculite (samples IBM-1/3, IBM-1/7, IBM-1/8). Mixed-layered clay minerals of randomly interstratified illite+smectite or illite+vermiculite were identified in two samples (IBM-1/2 and IBM-1/4). Plagioclase occurs in all samples, generally in small amounts. The low content of Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … 4136 THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 pyrite was observed in two samples (IBM-1/4 and IBM-1/27). Zeolite of clinoptilolite-heuland- ite group was identified only in sample IBM-1/8. Table 1. Mineralogical composition of coal and shale samples from the Ibar Basin, based on XRD data Sample ID Qz Ilt Mnt Kln Chl Ms/ Ilt INT Sme- Ilt INT Sme- Chl/Vrm Cal Dol Ank Py Gp Szo/ Kie Pl Cpt/ Hul Anl Jarando 1 M m m m Jarando 3 M m m m Tadenje 11 M l l l m m Tadenje 14 M l l m l m Tadenje 1 M l l m m m l Tadenje 10A m l l M m l l Tadenje 10B m l M m l m Progorelica 3 M m Progorelica 5 M m m Progorelica 1 M Progorelica 10 M m m m Progorelica 16 M m m m Progorelica 11 M m m IBM-1/2 M l l l m l l IBM-1/3 M l l l l IBM-1/4 M l l l l m IBM-1/7 M l l l l IBM-1/8 M l l l m l IBM-1/27 M l l l m Abbreviations [23]: Qz – quartz, Ilt – illite, Mnt – montmorillonite, Kln – kaolinite, Chl – chlorite, Ms/Ilt – muscovite/illite, INT Sme-Ilt – interstratified smectite-illite, INT Sme-Chl/Vrm – interstratified smectite-chlorite/vermiculite, Pl – plagioclase, Cal – calcite, Dol – dolomite, Ank – ankerite, Py – pyrite, Gp – gypsum, Szo/Kie – szomolnokite/kieserite, Cpt/Hul – clinoptilolite/heulandite, M – most abundant, m – medium abundant, l – less abundant. The SEM-EDS analysis The SEM-EDS examination revealed that the most abundant minerals in coal samples from the Jarando, Progorelica and most samples from Tadenje are quartz, clay minerals (illite, kaolinite, fig. 3) and pyrite. Calcite is abundant in two coal samples from Tadenje deposit and less abundant in Jarando and Progorelica coals. Barite and gypsum were occasionally identified in all three deposits. Other minor minerals such as rutile, hematite, biotite, boehmite, and sphal- erite were observed in a few coal samples. Diatoms were observed in Tadenje 11 sample, fig. 3. In the Jarando coal strontium, Sr, in barite and vanadium, V, in rutile were detected. Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 4137 Figure 2. The XRD patterns of coal and shale samples from the Ibar Basin; (a), (b), (c), (d), (e) whole-rock samples, (f) OA – untreated oriented sample, (f) EF – glycolated-oriented sample. Abbreviations [23]: Qz – quartz, Ilt – illite, Mnt – montmorillonite, Kln – kaolinite, Chl – chlorite, Sme-Ilt – interstratified smectite-illite, Sme-Chl/Vrm – interstratified smectite-chlorite/vermiculite, Pl – plagioclase, Cal – calcite, Dol – dolomite, Py – pyrite, Gp – gypsum, Szo – szomolnokite/kieserite The SEM-EDS analysis of the shale samples from borehole IBM-1 in the Piskanja deposit revealed that they mostly consist of a mixture of dolomite, fig. 3, and mica/clay miner- als, as well plagioclase and K-feldspars, quartz and, rarely, minerals originating from ophiolites. Illite, and chlorite are the most abundant clay minerals. Pyrite is detected in most samples, also Pb, Zn, and Cu sulphides along with gypsum and celestine were detected in the deeper parts of the basin. Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … 4138 THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 Figure 3. The SEM backscatter images of minerals in coal (a)-(d) and shale (e)-(f) from the Ibar Basin. Abbreviations [23]: Qz – quartz, Ilt – illite, Chl – chlorite, CM – clay minerals, Dol – dolomite, Py – pyrite, Sp – sphalerite, Di – diatoms The Fourier-transform infrared spectroscopy analysis The FTIR was used for profiling the coal and shale samples components. The FTIR spectra of the coal and shale samples are shown in fig. 4 and the bands position, second-deriv- ative, assignation, and related references are given in tab. S2 and S3 (in the Supplementary material). The spectral data obtained show the superposition of both organic and mineral com- ponents. Quartz is the most abundant mineral in all coal samples, fig. 4. Clay component is polymineralic, made up of kaolinite, dioctahedral smectite, and illite. In Tadenje deposit, calcite and gypsum also occur. The FTIR spectra of the studied coal samples show weak organic func- tional group bands, which are obscured due to partial overlapping with intensive silicates bands. The organic coal components are mostly observed in the aliphatic and aromatic bands regions. The most abundant mineral in all shale samples is quartz, tab. S4 in the Supplementary material, accompanied by clay minerals and dolomite. Aragonite occasionally occurs in small amounts. Clay minerals include illite, dioctahedral smectite, and chlorite. Geochemistry Variations of the SiO2, Fe2O3, Al2O3, CaO and SO3 contents, tab. 3 and tab. S5, in the Supplementary material, in the coal samples are obvious in each deposit and depend on mineral matter content. Generally, high temperature coal ash from Jarando, Progorelica, and most sam- ples from Tadenje deposit display high SiO2 contents, followed by Al2O3, TiO2, Fe2O3, and low Na2O, K2O, and P2O5 contents. Coal ash from the lower part of Seam 5 of the Tadenje deposit (Tadenje 10A, Tadenje 10B) has high CaO (32.33-45.63%), Fe2O3 (10.30-17.96%) and SO3 (14.31-14.94%) contents, and low SiO2 (17.99-22.64%) content. The highest Fe2O3 (49.78%) was observed in Tadenje Seam 3. Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 4139 Figure 4. The FTIR spectra of the coal (a)-(b) samples from Tadenje, Progorelica, and Jarando, and shale (c) samples from Piskanja boron deposit; OH-region and aliphatic organic component regions (2800-3800 cm-1) are shown at the left pane, fingerprint region of (1800-400 cm-1) is shown at the right pane. Abbreviations [23]: Qz – quartz, Kln – kaolinite, Mnt – montmorillonite, Ilt – illite, Chl – chlorite, Sme – smectite, Cal – calcite, Dol – dolomite, Sul – sulphates, Py – pyrite, Gy – gypsum, Arg? – aragonite, Ali – aliphatic components, Aro – aromatic components, C=O – oxygenated functional groups region (for color image see journal web site) The HTCA from the Ibar Basin is highly enriched in As, Cr and Ni in comparison with the Clarke values for ash in bituminous coals [24]. The highest content of As (852.7 ppm; tab. S6, in the Supplementary material), Cr (294.3 ppm), Ni (1025.6 ppm), V (272.2 ppm), Cu (137.2 ppm), Mo (45.5 ppm), Sb (21.7 ppm), Sr (1520 ppm) and Pb (91.7 ppm) observed in HTCA from Tadenje deposit, while the highest contents of Cd (2.4 ppm), Co (145.1 ppm) and Mn (763 ppm) were determined in the Jarando HTCA. Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … 4140 THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 Table 3. Contents of major oxides [%] and trace elements [ppm] of the high temperature coal ash and shale samples from the Ibar Basin Elements Mincoal Maxcoal AVcoal Minshale Maxshale AVshale Clarke values of bituminous coal ash, ppm [23] Clarke values of black shales, ppm [23] SiO2 18.0 78.8 54.3 50.2 62.3 56.2 Al2O3 3.6 19.3 11.5 12.6 19.4 14.8 Fe2O3 3.2 49.8 14.5 6.0 7.9 6.7 TiO2 0.2 0.5 0.4 0.5 0.9 0.6 SO3 0.8 14.9 5.0 0.1 0.4 0.2 CaO 0.9 45.6 9.1 1.5 13.1 6.9 MgO 0.3 2.0 0.9 3.9 14.2 8.6 Na2О 0.1 1.0 0.5 1.6 3.5 2.4 K2O 0.3 1.6 1.0 2.4 4.3 3.2 P2O5 0.1 0.8 0.3 0.1 0.2 0.1 As 31 853 168 19 225 65 46 ±5 30 ±3 Ba 168 699 401 391 723 544 980 ±60 500 ±20 Be 1 11 5 1 2 2 12 ±1 2.0 ±0.1 Cd 0.2 2.4 0.7 0.5 2.6 0.9 1.2 ±0.3 5.0 ±0.6 Co 2 145 34 19 32 27 37 ±2 19 ±1 Cu 33 137 77 64 338 142 110 ±5 70 ±3 Cr 41 294 132 142 275 217 120 ±5 96 ±3 Ni 14 1026 295 109 273 214 100 ±5 70 ±2 Mn 19 763 179 508 2662 1425 430 ±30 400 ±20 Mo 7 46 22 2 29 9 14 ±1 20 ±1.5 Sb 2 22 8 2 32 10 7.5 ±0.6 5.0 ±0.5 Sr 140 1520 389 195 1285 776 730 ±50 190 ±10 Pb 10 92 33 90 718 239 55 ±6 21 ±1 V 10 272 163 170 ±10 205 ±15 Zn 13 312 94 119 555 210 170 ±10 130 ±10 Min – minimum value, Max – maximum value, and AV – arithmetic mean value The shale from the Piskanja deposit displays high SiO2, tab. 3, lower Al2O3 and vari- able MgO and CaO contents. The highest content of MgO is determined in the upper most part of the Piskanja deposit (IBM-1/1), while the highest CaO is determined in the sample from 195.4-196.6 m depth (IBM-1/7). Shales are highly enriched in Cu, Cr, Ni, Mn, Sr, and Pb in comparison with Clarke values for black shales [24]. Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 4141 Discussion Minerals in coal play a significant role in coal utilisation, from exploitation, grinding, washing, combustion, coking, to the environmental and human health impacts [1, 25]. Their presence has a negative economic impact and reduces the coal price if it is necessary to use coal cleaning processes before combustion or coke production. The mineralogical composition of coal influences the contents of fly ash, bottom ash and slag, and the gaseous products as well. Several optical methods and chemical analyses are applied for determining the mineralogical and geochemical compositions of coal [26, 27]. Statistical treatment of data obtained by these analyses, is also applied for assessing the modes of occurrence of major/minor and trace ele- ments in sedimentary rocks and coal. Mineralogical analyses revealed that the Jarando, Progorelica and Tadenje coals from the Ibar Basin are characterised by high content of silicates and aluminosilicates, pyrite, Fe- Mg-sulphate, and carbonate minerals. Silicate and aluminosilicate minerals include mainly quartz and clay minerals, while plagioclase and mica were rarely observed, tabs. 1 and S4. Quartz is a major mineral component occurring as single angular to semi-rounded grains of detrital origin [26, 27]. Dominant clay mineral in coal samples is kaolinite, accompanied by dioctahedral smectite, rarely illite and interstratified smectite-chlorite-vermiculite. Clay miner- als are mostly of detrital origin [26], except kaolinite, which does not occur within the basin sedimentary sequence, indicating a rather diagenetic origin. Kaolinite may have formed due to weathering and/or hydrothermal alteration of feldspar, mica, smectite, and illite from the sur- rounding granitic basement. The detrital plagioclase and biotite, likely sourced from neighbour- ing granitoid masses, occur as an irregularly shaped crystals, usually in association with plagi- oclase in clay-rich layers. Pyrite is one of the most abundant sulphide minerals with variable content implying reducing depositional conditions. Syngenetic pyrite was observed in all coal samples as framboidal and euhedral crystals [28] along stratified bands or infilling cavities within the organic matter. Epigenetic pyrite was determined within cleats and fractures in the organic matrix. Several pyrite grains from Tadenje deposit (sample Tadenje 11) contain As and Ni as observed in SEM-EDS. This is in accordance with the geochemical composition of HTCA tab. S5 in the Supplementary material. Sphalerite was detected in the Jarando deposit in small amounts. Gypsum and szomolnokite/kieserite were determined only in Tadenje deposit, of au- thigenic, mainly epigenetic origin, formed as weathering products [29]. Szomolnokite most probably formed as secondary mineral from pyrite, implying highly acidic, oxic and arid con- ditions during the formation of that part of the coal seam. Barite was determined in very low amounts and is mostly enriched in Sr. The Fe oxides/hydroxides are present in considerable amounts in the Progorelica 3 Upper Seam and are probably the result of the weathering of Fe-rich minerals such as pyrite and siderite, whereas small amount of these minerals might be of detrital origin. Rutile/anatase was observed in low amount in Jarando coal as small aggre- gates with low V content. The most abundant carbonate mineral in the Ibar coal is calcite. Cal- cite is present in high amounts in the lower part of Seam 5 in Tadenje deposit as individual rounded and angular grains and spherical aggregates, implying probably their syngenetic origin. Small amount of ankerite occurs as small angular grains in Tadenje deposit. Borates are present in almost all examined coal fractions, associated with coal and clays. They are usually light yellow and, most likely, correspond to howlite, colemanite, jarandolite and ulexite [5]. The major oxide contents of the HTCA are compatible with identified silicate and aluminosilicate minerals rich in SiO2, Al2O3, K2O, and TiO2. High to relatively high content of Fe2O3 in the HTCA can be related to pyrite and Fe-sulphate minerals present in coals. High Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … 4142 THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 CaO content in HTCA in the lower part of Tadenje Seam 5 is in accordance with calcite as a major mineral phase observed through XRD, SEM-EDS, and FTIR analyses. Higher content of SO3 and Fe2O3 in the same samples is compatible with the mineral association of calcite, gyp- sum, szomolnokite/kieserite. The Piskanja borate deposit is characterised by a thick monotonous sequence of mud- stones/marlstones, and it is likely stratigraphically younger than coal seams in Progorelica and Tadenje. The studied samples represent organic-rich lacustrine and alluvial sediments with sil- icates and aluminosilicates as the most abundant minerals with variable content of carbonate minerals. The clastic material resulted from the weathering, erosion, and transport from the surrounding basement rocks. Quartz and clay minerals (illite, smectite, chlorite) are major min- eral phases in shales with variable content of plagioclase, and dolomite as major carbonate mineral. Mica (muscovite and biotite) and zeolite minerals are rare. Pyrite is the most abundant sulphide mineral but in low amount compared to coal. Lead, Zn, and Cu sulphide minerals are also included in the deepest part of the deposit and correspond to the highest contents of As, Cd, Sb, Pb, and Zn, tab. S5 in the Supplementary material. The highest content of Mn is also noticed in the same part. Mineralogical and geochemical compositions are in accordance and imply variation in the depositional environment and local climatic conditions as well as post- depositional hydrothermal phases in the Ibar Basin. Although the studied coals and shales in the subbasins of Jarando Basin are domi- nantly deposited in marshes surrounding the basin under reducing and humid climatic condi- tions [4, 6], our data show internal variations from this trend. In particular, the documented variations in coal mineralogy and geochemistry imply that aforementioned conditions have been interrupted by short phases when the succession was exposed to oxic and dry conditions. Conclusions The Jarando, Progorelica and Tadenje coals are characterised by high content of quartz and clay minerals and lower amount of plagioclase and mica. The dominant clay mineral in coal is kaolinite, accompanied by smectite, rarely illite and interstratified smectite-chlorite- vermiculite. Pyrite is the most abundant sulphide mineral with variable content of Ni and As. Small amount of sphalerite is also included. Gypsum and szomolnokite/kieserite are the most common sulphate minerals in Tadenje deposit, whereas barite mostly enriched in Sr, is less abundant. The Fe oxides/hydroxides occur in considerable amounts in the Progorelica deposit while rutile/anatase is present in Jarando coal in low amount. Calcite is the most abundant car- bonate mineral, especially in the lower part of Seam 5 in Tadenje deposit, where also ankerite occurs in small amount. The major oxide composition of the HTCA is compatible with the mineral association in coal. The organic-rich shale from the Piskanja deposit is characterised by high content of silicates and aluminosilicates with variable content of carbonate minerals. The most abundant silicate minerals are quartz and clay minerals, with lower content of plagioclase and mica. Do- lomite is the most abundant carbonate mineral, especially in the upper part of deposit. The mineral association is in accordance with the major oxide composition and the trace element contents. Acknowledgment This work was financially supported by the Ministry of Science, Technological De- velopment and Innovation of the Republic of Serbia (Contract number: 451-03-66/2024- 03/200052, 451-03-66/2024-03/200053, and 451-03-65/2024-03/200126) as well as by the Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 4143 Deutsche Forschungsgemeinschaft (DFG) DRASTIC grant to Nevena Andrić-Tomšević (grant number TO 1364/3-1). Authors are also grateful to the reviewers Prof dr Kimon Christanis and Prof dr Ksen- ija Stojanović, Editor-in-Chief, Dr. Vukman Bakić and Prof dr Simeon Oka and Guest Editor, Prof. Dr. Marko Obradović, whose constructive comments and suggestions greatly improved this manuscript. Supplementary Material Figure S1. Location of the Ibar Basin and the sampling sites Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … 4144 THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 Table S1. The samples collected from the Ibar Basin Mine/ deposit Latitude- longitude [°] Sample ID Lithology Seam Depth [m] Analytical technique applied Jarando N 43.40264 E 20.62593 Jarando 1 Coal 6 296.0-296.5 ICP-MS, XRD, SEM-EDS, FTIR Jarando 3 Coal 6 297.3-297.9 ICP-MS, XRD, SEM-EDS, FTIR Tadenje N 43.43155 E 20.61397 Tadenje 11 Coal 3 47.6-48.6 ICP-MS, XRD, SEM-EDS, FTIR Tadenje 14 Coal 3 49.6-50.3 ICP-MS, XRD, SEM-EDS, FTIR Tadenje 1 Coal 5 68.4-68.6 ICP-MS, XRD, SEM-EDS, FTIR Tadenje 10A Coal 5 70.5-70.7 ICP-MS, XRD, SEM-EDS, FTIR Tadenje 10B Coal 5 70.7-71.0 ICP-MS, XRD, SEM-EDS, FTIR Progorelica N 43.43093 E 20.62405 Progorelica 3 Coal Upper 2.2-2.7 ICP-MS, XRD, SEM-EDS, FTIR Progorelica 5 Coal Upper 4.3-5.8 ICP-MS, XRD, SEM-EDS, FTIR Progorelica 1 Coal Main 17.8-18.0 ICP-MS, XRD, SEM-EDS, FTIR Progorelica 10 Coal Main 20.3-21.3 ICP-MS, XRD, SEM-EDS, FTIR Progorelica 16 Coal Main 33.8-34.3 ICP-MS, XRD, SEM-EDS, FTIR Progorelica 11 Coal Main 42.3-43.1 ICP-MS, XRD, SEM-EDS, FTIR Piskanja N 43.38174 E 20.65376 IBM-1/1 Shale 43.5-44.5 XRF, ICP-MS, SEM-EDS, FTIR IBM-1/2 Shale 47.0-47.9 XRF, ICP-MS, XRD, SEM-EDS, FTIR IBM-1/3 Shale 63.2-66.8 XRF, ICP-MS, XRD, SEM-EDS, FTIR IBM-1/4 Shale 122.8-123.9 XRF, ICP-MS, XRD, SEM-EDS, FTIR IBM-1/6 Shale 127.0-128.2 XRF, ICP-MS, SEM-EDS, FTIR IBM-1/7 Shale 195.4-196.6 XRF, ICP-MS, XRD, FTIR IBM-1/8 Shale 226.3-227.6 XRF, ICP-MS, XRD, SEM-EDS, FTIR IBM-1/27 Shale 344.2-344.5 XRF, ICP-MS, XRD, SEM-EDS, FTIR IBM-1/29 Shale 352.2-353.2 XRF, ICP-MS, SEM-EDS, FTIR Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 4145 Table S2. The FTIR absorption bands of coal samples spectra from Tadenje, Jarando, and Progorelica deposits in comparison with previously reported data Frequency (measured) [cm–1] Second derivative [cm–1] Frequency (literature) [cm–1] Assignment Compound References 3695 3695 In-phase stretching mode of inner-surface OH groups Kaolinite 30-32 3648 3651 Out-of-phase stretching modes of inner-surface OH groups 33, 31 3621-3620 3619 Stretching of the inner OH group 33, 31 2965-2955 2954 –CH3 asymmetric stretching Aliphatic components 34 2919-2926 2923 2921, 2915-2923, 2918 –CH2 asymmetric stretching 35 2868-2867 2870 –CH3 symmetric stretching 34 2850 2851 2851 –CH2 symmetric stretching 35 2820 2820 Unknown 34 1795 1795 v1+v4 vibrational modes Calcite 36 1705 Carboxyl acids Oxygenated (C=O) functional groups 34 1659-1657 1659 C=O 37 1650-1649 Conjugated C=O 34, 38 1620-1596 1635 OH bending vibrations Smectite, Illite 33 1620 Aromatic C=C ring stretching Aromatic components (e.g. lignin) 34, 38 1613-1611 38 1600-1598 1599-1591 1606 35 1430 1427 v3(CO3) asymmetric stretching Calcite 36, 39 1375 1375 Tertiary butyl groups 40 1164-1162 1173-1170, 1175 v3(Si–O) asymmetrical stretching (Al/Si substitution) Quartz 36, 41 1149-1090 1150-1080 v3(SO4) asymmetrical stretching Sulfates 36, 42, 43 1093-1086 1084, 1085-1081 v3(Si–O) asymmetrical stretching (Al/Si substitution) Quartz 36, 41 1035-1026 1032 In-plane Si–O-Si stretching Silicates 35 1008-1006 1009 35 Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … 4146 THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 Table S2. continuation Frequency (measured) [cm–1] Second derivative [cm–1] Frequency (literature) [cm–1] Assignment Compound References 915-913 915 Al–OH–Al bending Montmori- llonite 33, 32 874 876 v2(CO3) out-of-plane bending Calcite 36 828 828 Al–OH–Mg bending Illite 33 802-797 798, 801-797 v1(Si–O) symmetrical stretching Quartz 36, 41 779-777 779-778, 782-778 36, 41 712 712 v4(CO3) in-plane bending Calcite 36, 39 695-694 696, 695-691 v2(Si–O) symmetrical bending Quartz 36, 41 599 602 604 SO4 2– bending Gypsum 35 532 536, 538 Al–O–Si bending Kaolinite 36, 35 512-507 513-512, 524-512 v2(Si–O) symmetrical bending Quartz 36, 41 467-463 459, 462-457, 466-463 v4(Si–O) asymmetrical bending Quartz 36, 41, 44 423-419 425, 425-422 Pyrite 42, 43 Table S3. The FTIR absorption bands of shale samples spectra from Piskanja boron deposit in comparison with previously reported data Frequency (measured) [cm–1] Frequency (literature) [cm–1] Assignment Mineral/compound References 3674 3679-3671 Mg3OH stretching Chlorite 45 3620-3626 3619, 3622–3621 Stretching of the inner OH group Smectite, Illite 3575-3555 Interlayer oxy-hydroxyl sheets Chlorite 45 3420-3400 broad band near 3420 OH stretching vibrations (in H2O) Smectite 45 2920 2921, 2915-2923, 2918 –CH2 asymmetric stretching Aliphatic component 35, 34 2853 2851 –CH2 symmetric stretching 1635 1635 OH bending vibrations Smectite, Illite 33 1473-1437 1441 v3(CO3) asymmetric stretching Dolomite 46 1163 1173-1170, 1175 v3(Si–O) asymmetrical stretching (Al/Si substitution) Quartz 36, 41 1083 1084, 1085-1081 v3(Si–O) asymmetrical stretching (Al/Si substitution) Quartz 36, 41 Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 4147 Table S3. continuation Frequency (measured) [cm–1] Frequency (literature) [cm–1] Assignment Mineral/compound References 1010-980 1032, 1009 In-plane Si–O-Si stretching Silicates 36, 42 915 915 Al–OH–Al bending Smectite, Illite 33, 32 878 881 v2(CO3) out-of-plane bending Dolomite 47 854 858-854 ν2(CO3) out-of-plane bending Aragonite? 48 828 828 Al–OH–Mg bending Illite 33 799 798, 801-797 v1(Si–O) symmetrical stretching Quartz 36, 41 778 779-778, 782-778 36, 41 757 756 Al–O–Si in-plane Illite 45 728 730 v4(CO3) in-plane bending Dolomite 47 695 696, 695-691 v2(Si–O) symmetrical bending Quartz 36, 41 670-650 675-650 OH bending Chlorite 45 537-512 534-520 Al–O–Si bending Smectite 45 513-512, 524-512 v2(Si–O) symmetrical bending Quartz 36, 41 464 459, 462-457, 466-463 v4(Si–O) asymmetrical bending Quartz 36, 41, 44 440-410 Si-O-Si bending Smectite, Illite, Chlorite 45 423-419 425, 425-422 Pyrite 42, 43 Table S4. Mineralogical composition of coal and shale samples from the Ibar Basin, based on data from FTIR analysis Sample ID Minerals Sample ID Minerals Jarando 1 Qz, Kln, Sme, Ilt, Py Progorelica 16 Qz, Kln, Sme, Ilt, Py Jarando 3 Qz, Kln, Sme, Ilt, Py Progorelica 11 Qz, Kln, Sme, Ilt, Py Tadenje 11 Qz, Kln, Sme, Ilt, Py IBM-1/1 Qz, Dol, Sme, Ilt, Chl, Arg, Py Tadenje 14 Qz, Kln, Sme, Ilt, Py IBM-1/2 Qz, Dol, Sme, Ilt, Chl Tadenje 1 Qz, Kln, Sme, Ilt, Cal, Py IBM-1/3 Qz, Dol, Sme, Ilt, Chl, Arg, Py Tadenje 10A Qz, Kln, Sme, Ilt, Cal, Py, Gp IBM-1/4 Qz, Sme, Ilt, Chl Tadenje 10B Qz, Kln, Sme, Ilt, Cal, Py, Gp IBM-1/6 Qz, Dol, Sme, Ilt, Chl, Arg, Py Progorelica 3 Qz, Kln, Sme, Ilt, Py IBM-1/7 Qz, Sme, Ilt, Chl, Arg, Py Progorelica 5 Qz, Kln, Sme, Ilt, Py IBM-1/8 Qz, Sme, Ilt, Chl Progorelica 1 Qz, Sme, Ilt, Py IBM-1/27 Qz, Dol, Sme, Ilt, Chl Progorelica 10 Qz, Kln, Sme, Ilt, Py IBM-1/29 Qz, Dol, Sme, Ilt, Chl Qz – quartz, Kln – kaolinite, Ilt – illite, Sme – smectite, Chl – chlorite, Arg – aragonite, Py – pyrite, Cal – calcite; Dol – dolomite, Gp – gypsum Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … 4148 THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 Table S5. Content of major oxides [%] of individual samples in HTCA and shale samples from the Ibar Basin Sample ID SiO2 Al2O3 Fe2O3 TiO2 SO3 CaO MgO Na2О K2O P2O5 Jarando 1 60.57 17.04 12.20 0.41 1.15 1.01 1.53 0.88 1.56 0.11 Jarando 3 61.89 14.15 12.83 0.46 1.17 1.01 1.18 0.78 1.53 0.13 Tadenje 11 40.58 11.47 31.50 0.47 6.40 5.83 0.84 0.67 0.88 0.43 Tadenje 14 31.58 10.00 49.78 0.30 2.41 3.17 0.66 0.41 1.18 0.09 Tadenje 1 43.14 15.65 16.45 0.42 5.46 8.58 1.99 1.04 1.38 0.78 Tadenje 10A 17.99 6.05 10.30 0.19 14.31 45.63 0.95 0.38 0.77 0.25 Tadenje 10B 22.64 8.75 17.96 0.29 14.94 32.33 0.78 0.71 0.87 0.40 Progorelica 3 73.34 5.40 3.18 0.20 7.96 8.74 0.48 0.12 0.26 0.19 Progorelica 5 67.77 13.90 3.81 0.41 4.47 5.48 0.81 0.11 0.79 0.21 Progorelica 1 78.79 3.64 10.99 0.29 1.60 1.99 0.33 0.32 0.49 0.66 Progorelica 10 63.70 19.29 8.22 0.50 0.97 0.90 0.83 0.13 1.15 0.26 Progorelica 16 70.06 14.71 7.89 0.33 0.77 0.85 0.69 0.15 0.73 0.21 Progorelica 11 73.66 9.68 3.23 0.41 2.85 2.33 0.62 0.14 1.20 0.20 IBM-1/1 50.21 12.60 6.04 0.54 0.32 10.86 14.19 1.83 2.72 0.17 IBM-1/2 51.93 13.13 6.04 0.78 0.44 8.99 13.43 1.72 3.23 <0.1 IBM-1/3 59.06 13.47 7.08 0.60 0.09 7.12 7.15 2.22 2.84 0.15 IBM-1/4 59.18 14.05 6.03 0.55 0.09 1.50 11.69 3.49 3.14 0.11 IBM-1/6 52.73 14.43 6.63 0.66 0.17 7.73 10.93 2.76 3.45 0.14 IBM-1/7 52.64 15.76 6.90 0.59 0.37 13.06 5.05 3.05 2.38 <0.1 IBM-1/8 59.40 15.60 7.89 0.48 0.09 3.77 6.38 2.67 3.49 <0.1 IBM-1/27 62.25 14.81 6.44 0.73 0.09 5.56 5.04 1.86 2.96 <0.1 IBM-1/29 58.45 19.39 7.42 0.86 0.09 3.42 3.95 1.63 4.34 <0.1 Mincoal 17.99 3.64 3.18 0.19 0.77 0.85 0.33 0.11 0.26 0.09 Maxcoal 78.79 19.29 49.78 0.50 14.94 45.63 1.99 1.04 1.56 0.78 AVcoal 54.29 11.52 14.49 0.36 4.96 9.07 0.90 0.45 0.98 0.30 Minshale 50.21 12.60 6.03 0.48 0.09 1.50 3.95 1.63 2.38 0.11 Maxshale 62.25 19.39 7.89 0.86 0.44 13.06 14.19 3.49 4.34 0.17 AVshale 56.20 14.81 6.72 0.64 0.19 6.89 8.65 2.36 3.17 0.14 Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 4149 Table S6. Content of selected trace elements [ppm] of individual samples in HTCA and shale samples from the Ibar Basin Sample ID As Ba Be Cd Co Cu Cr Ni Mn Mo Sb Sr Pb V Zn Jarando 1 75.2 485 4.3 0.4 20.8 57.6 57.0 78.1 232 6.7 1.9 350 30.4 130.8 88.0 Jarando 3 88.6 443 8.1 2.4 145.1 33.4 66.2 145.3 763 7.8 2.8 285 27.8 201.1 312.4 Tadenje 11 852.7 617 10.1 0.5 21.3 81.2 244.0 575.8 65 29.6 15.5 244 54.3 259.1 93.5 Tadenje 14 296.4 180 8.5 0.8 55.4 82.7 294.3 1025.6 89 30.4 20.0 140 73.9 272.2 76.6 Tadenje 1 130.7 276 11.1 1.0 49.5 137.2 278.6 731.9 256 45.5 21.7 287 91.7 208.1 187.3 Tadenje 10A 56.0 168 2.7 0.6 28.5 62.8 124.3 327.1 315 29.2 14.2 1520 32.8 237.8 78.6 Tadenje 10B <2.3 262 5.7 0.6 50.4 85.5 176.3 637.4 293 <1.0 <1.5 793 19.9 10.5 105.4 Progorelica 3 31.4 699 1.0 <0.10 2.7 60.5 40.6 19.6 25 8.4 1.7 279 10.0 41.4 24.5 Progorelica 5 57.9 475 1.0 <0.10 1.8 122.9 68.2 14.1 19 16.3 2.4 254 21.0 99.6 13.3 Progorelica 1 122.6 582 6.5 0.2 6.2 126.8 133.4 47.2 51 25.7 1.7 186 11.0 233.8 21.9 Progorelica 10 127.5 367 1.2 0.2 24.4 75.5 58.3 91.3 82 17.0 3.5 271 17.3 168.3 91.0 Progorelica 16 122.2 394 1.8 0.2 26.6 39.8 61.7 107.7 70 22.5 2.6 203 16.4 110.3 108.3 Progorelica 11 49.1 269 1.6 <0.10 5.1 32.5 110.2 34.5 63 23.7 4.9 245 20.2 151.8 23.0 IBM-1/1 31.6 613 1.7 0.7 29.0 337.5 203.7 253.8 1581 21.2 4.6 1103 105.3 123.2 IBM-1/2 19.1 529 1.6 0.6 25.3 158.0 191.3 185.7 1405 29.0 2.2 1212 95.4 118.8 IBM-1/3 20.3 473 2.4 0.5 28.1 129.4 243.3 240.2 1712 3.9 5.9 667 134.4 154.3 IBM-1/4 26.3 600 1.4 0.6 31.5 138.6 274.6 273.0 508 4.7 4.0 1073 122.2 149.9 IBM-1/6 28.2 723 1.8 0.6 27.3 108.7 196.4 189.5 1660 14.0 3.7 1285 90.0 124.8 IBM-1/7 24.8 440 1.7 0.5 27.8 124.7 242.1 250.4 705 4.5 4.5 775 122.7 130.6 IBM-1/8 33.3 582 2.1 0.9 30.3 138.0 270.7 264.4 1207 2.9 9.3 240 364.9 229.6 IBM-1/27 173.5 391 1.7 1.3 18.6 81.9 142.2 109.1 1386 1.9 25.7 435 395.5 304.6 IBM-1/29 225.3 551 2.2 2.6 23.1 64.2 185.6 163.9 2662 1.8 32.0 195 718.3 555.4 Mincoal 31.4 168 1.0 0.2 1.8 32.5 40.6 14.1 19 6.7 1.7 140 10.0 10.5 13.3 Maxcoal 852.7 699 11.1 2.4 145.1 137.2 294.3 1025.6 763 45.5 21.7 1520 91.7 272.2 312.4 AVcoal 167.5 401 4.9 0.7 33.7 76.8 131.8 295.0 179 21.9 7.7 389 32.8 163.4 94.1 Minshale 19.1 391 1.4 0.5 18.6 64.2 142.2 109.1 508 1.8 2.2 195 90.0 118.8 Maxshale 225.3 723 2.4 2.6 31.5 337.5 274.6 273.0 2662 29.0 32.0 1285 718.3 555.4 AVshale 64.7 544 1.8 0.9 26.8 142.3 216.7 214.4 1425 9.3 10.2 776 238.7 210.1 References [1] Dai, S., et al., Inorganic Geochemistry of Coal, Elsevier, Amsterdam, The Netherlands, 2023 [2] Miller, B. G. Clean coal engineering technology, 2nd edn. Elsevier, Amsterdam, The Netherlands, 2016 [3] Hower, J. C., et al., Understanding Coal Quality and the Critical Importance of Comprehensive Coal Anal- yses, International Journal of Coal Geology, 263 (2022), 104120 Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … 4150 THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 [4] Ercegovac, M., et al., Petrological and Geochemical Studies of the Coals of the Ibar River Basin (Yugo- slavia) (in German), International Journal of Coal Geology, 111 (1991), 19, pp. 5-22 [5] Obradović, J., Vasić, N., Neogene Lacustrine Basins from Serbia, Serbian Academy of Science and Arts, Belgrade, Serbia 2007 [6] Andrić, N., et al., The Thermal History of the Miocene Ibar Basin (Southern Serbia): New Constraints from Apatite and Zircon Fission Track and Vitrinite Reflectance Data, Geologica Carpatica, 66 (2015), 1, pp. 37-50 [7] Đorđević, Ž., Das Tertiäre Ibar-Becken (in Serbian), Proceedings of the Serbian Geological Society, Bel- grade, Serbia, pp. 97-100, 1954 [8] Pantić, N., Age of the Coal-Bearing Sedimentary Series near JARANDOL (valley of the river Ibar) on the Basis of the Latest Paleofloral Data (in Serbian), Bulletin of Institute for geological and geophysical ex- ploration, XIX (1961), A, pp. 287-297 [9] Ćirić, A., Über den Fund der Art Mastodon (Bunolophodon) Angustidens Cuv. F. Subtapirodea Schles. in der Braunkohlengrube Jarando bei Raška (in Serbian and German), Bulletin of Institute for geological and geophysical exploration, XX (1962), A, pp. 103-106 [10] ***, Basic Geologic Map of Serbia, section K34-18, https://geoliss.mre.gov.rs/prez/OGK/ RasterSrbija [11] ***, Basic Geologic Map of Serbia, section K34-30, https://geoliss.mre.gov.rs/prez/OGK/ RasterSrbija [12] Harzhauser, M., Mandić, O., Neogene Lake Systems of Central and South-Eastern Europe: Faunal Diver- sity, Gradients and Interrelations, Palaeogeography, Palaeoclimatology, Palaeoecology, 260 (2008), 3-4, pp. 417-434 [13] Andrić-Tomašević, et al., An Arid Phase in the Internal Dinarides During the Early to Middle Miocene: Inferences from Mg-Clays in the Pranjani Basin (Serbia), Palaeogeography, Palaeoclimatology, Palaeo- ecology, 562 (2021), 110145 [14] Schmid, S. M., et al., The Alpine-Carpathian-Dinaridic Orogenic System: Correlation and Evolution of Tectonic Units, Swiss Journal of Geosciences, 101 (2008), Mar., pp. 139-183 [15] Stojadinović, U., et al., The Balance between Orogenic Building and Subsequent Extension during the Tertiary Evolution of the NE Dinarides: Constraints from Low-Temperature Thermochronology, Global and Planetary Change 1, 103 (2013), Apr., pp. 19-38 [16] Andrić, N., et al., The Link between Tectonics and Sedimentation in Asymmetric Extensional Basins – Inferences from the Study of the Sarajevo-Zenica Basin, Marine and Petroleum Geology, 83 (2017), May, pp. 305-332 [17] Schefer, S., Tectono-Metamorphic and Magmatic Evolution of the Internal Dinarides (Kopaonik Area, Southern Serbia) and Its Significance for the Geodynamic Evolution of the Balkan Peninsula, Ph. D. thesis, University of Basel, Basel, Switzerland, 2010 [18] Matović, V., et al., Sedimentary Rock Testing Methods, University of Begrade, Faculty of Mining and Geology, Begrade, Serbia, 2019 [19] Menges, F., Spectragryph – Optical Spectroscopy Software, Version 1.2.16.1, 2022, http://www.ef- femm2.de/spectragryph/ [20] ***, ISO 7404-2, 2009. Methods for the Petrographic Analysis of Coals — Part 2: Methods of Preparing Coal Samples. International Organization for Standardization, Geneva, Switzerland, (2009) [21] ***, ASTM D6357-21a, Determination of Trace Elements in Coal, Coke and Combustion Residues from Coal Utilization Processes Using ICP-AES, ICP-MS and GFAAS, American Society for Testing and Ma- terials, Philadelphia, USA, 2021 [22] ***, ASTM D6349-21, Determination of Major and Minor Elements in Coal, Coke and Solid Residues from Combustion of Coal and Coke by Using ICP-AES, American Society for Testing and Materials, Philadelphia, USA, 2021 [23] Whitney, D. L., Evans, B. W., Abbreviations for Names of Rock-Forming Minerals, American Mineralo- gist, 95 (2010), 1, pp. 185-187 [24] Ketris, M. P., Yudovich, Y. A. E., Estimations of Clarkes for Carbonaceous Biolithes: World Averages for Trace Element Contents in Black Shales and Coals, International Journal of Coal Geology, 78 (2009), 2, pp. 135-148 [25] Dai, S., et al., Geochemistry of Trace Elements in Chinese Coals: a Review of Abundances, Genetic Types, Impacts on Human Health, and Industrial Utilization, International Journal of Coal Geology, 94 (2012), May, pp. 3-21 [26] Finkelman, R. B., et al., The Importance of Minerals in Coal as the Hosts of Chemical Elements: A Re- view, International Journal of Coal Geology, 212 (2019), 103251 https://geoliss.mre.gov.rs/prez/OGK/%20RasterSrbija http://www.effemm2.de/spectragryph/ http://www.effemm2.de/spectragryph/ Novković, Ž. N., et al.: Mineralogy, Chemistry, and Distribution of Selected … THERMAL SCIENCE: Year 2024, Vol. 28, No. 5B, pp. 4131-4151 4151 [27] Ward, C. R., Analysis, Origin and Significance of Mineral Matter in Coal: an Updated Review, Interna- tional Journal of Coal Geology, 165 (2016), Aug., pp. 1-27 [28] Chou, C.-L., Sulfur in Coals: A Review of Geochemistry and Origins, International Journal of Coal Ge- ology, 100 (2012), Oct., pp. 1-13 [29] Dai, S., et al., Recognition of Peat Depositional Environments in Coal: A Review, International Journal of Coal Geology, 219 (2020), 103383 [30] Srodon, J., Identification and Quantitative Analysis of Clay Minerals, in: (F. Bergaya and G. Lagaly Edi- tors), 5, Handbook of Clay Science, Elsevier, Amsterdam, The Netherlands, 2013, pp. 25-49 [31] Balan, E., et al., First-Principles Study of OH-Stretching Modes in Kaolinite, Dickite, and Nacrite, Amer- ican Mineralogist, 90, (2005), 1, pp. 50-60 [32] Srasra, E., et al., Infrared Spectroscopy Study of Tetrahedral and Octahedral Substitutions in an Interstrat- ified Illite-Smectite Clay, Clays and Clay Minerals, 42 (1994), 3, pp. 237-241 [33] Muller, C., et al., Infrared Attenuated Total Reflectance Spectroscopy: An Innovative Strategy for Ana- lyzing Mineral Components in Energy Relevant Systems, Scientific Reports, 4 (2014), 1, 6764 [34] Ibarra, J. V., et al., FTIR Study of the Evolution of Coal Structure during the Coalification Process, Or- ganic Geochemistry, 24 (1996), 6, pp. 725-735 [35] Yin, Y., et al., Characterization of Coals and Coal Ashes with High Si Content Using Combined Second- Derivative Infrared Spectroscopy and Raman Spectroscopy, Crystals, 10 (2019), 9, 513 [36] Chukanov, N. V., Infrared Spectra of Mineral Species, Springer Mineralogy, Springer International Pub- lishing, Cham, New York, USA, 2014 [37] Li, K., et al., Comprehensive Investigation of Various Structural Features of Bituminous Coals Using Advanced Analytical Techniques, Energy & Fuels, 29 (2015), 11, pp. 7178-7189 [38] Craddock, P., et al., Evolution of Kerogen and Bitumen during Thermal Maturation via Semi-Open Py- rolysis Investigated by Infrared Spectroscopy, Energy & Fuels, 29 (2015), 4, pp. 2197-2210 [39] Luzinova, Y., et al., Detection of Cold Seep Derived Authigenic Carbonates with Infrared Spectroscopy, Marine Chemistry, 125 (2011), 1-4, pp. 8-18 [40] Balachandran, M., Role of Infrared Spectroscopy in Coal Analysis – An Investigation, American Journal of Analytical Chemistry, 5 (2014), 6, pp. 367-372 [41] Saikia, B. J., et al., Fourier Transform Infrared Spectroscopic Estimation of Crystallinity in SiO2 Based Rocks, Bulletin of Material Science, 31, (2008), Nov., pp. 775-779 [42] Chukanov, N. V., Chervonnyi, A. D., Infrared Spectroscopy of Minerals and Related Compounds, Springer Mineralogy, Springer International Publishing, Cham, New York, USA, 2016 [43] Dunn, J. G., et al., A Fourier Transform Infrared Study of the Oxidation of Pyrite, Thermochimica Acta, 208 (1992), Oct., pp. 293-303 [44] Saikia B. J., Spectroscopic Estimation of Geometrical Structure Elucidation in Natural SiO2 Crystal, Jour- nal of Materials Physics and Chemistry, 2 (2014), 2, pp. 28-33 [45] Madejova, J., et al., Chapter 5 – IR Spectra of Clay Minerals, in: (W. P. Gates, J. T. Kloprogge, J. Madejova and F. Bergaya eds.), 8, Developments in Clay Science, Elsevier, Amsterdam, The Netherlands, 2017, pp. 107-149 [46] Chester, R., Elderfield, H., The Application of Infra-Red Absorption Spectroscopy to Carbonate Mineral- ogy, Sedimentology, 9 (1967), 1, pp. 5-21 [47] Reig, F., et al., FTIR Quantitative Analysis of Calcium Carbonate (Calcite) and Silica (Quartz) Mixtures Using the Constant Ratio Method, Application to Geological Samples, Talanta, 58 (2002), 4, pp. 811-821 [48] Chakrabarty, D., Mahapatra, S., Aragonite Crystals with Unconventional Morphologies, Journal of Mate- rials Chemistry, 11 (1999), 9, pp. 2953-2957 Paper submitted: April 5, 2024 Paper revised: May 7, 2024 2024 Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. Paper accepted: May 27, 2024 This is an open access article distributed under the CC BY-NC-ND 4.0 terms and conditions. https://link.springer.com/article/10.1007/s12034-008-0123-0#auth-Bhaskar_J_-Saikia http://www.vin.bg.ac.rs/index.php/en/