Quantitative Mineralogical Analysis Research Articles

Loess doll from Pleistocene loess-like sediments in the Vishera diamond-bearing area (Perm region)

The purpose of the study is to investigate the cranes from loess-like deposits as indicator formations for the glacial epochs of the late Pleistocene – Holocene using current lithology methods. The motivating reason for the study was that loess-like deposits directly “seal” the industrial placer of the Silurian diamond-bearing reservoir in the Vishera diamondiferous region.Loess doll (loess pupae, dutiki) are concretions weakly cemented by iron hydroxides, consisting of quartz grains with an admixture of fine-silty feldspars. In terms of granulometry and mineral composition, the cranes correspond to the loess-like deposits that host them and are the frame of the root system of tundra-type grass vegetation. In the center of the concretion, in place of the disappeared grass root, a hollow tubule is preserved, sometimes filled with silty sand from the surrounding rocks.The granulometric composition of loess-like deposits was studied using an Analysette 22 MicroTec plus laser diffraction analyzer. Mineral composition of the heavy fraction of loess-like and underlying sediments – using quantitative mineralogical analysis. Quantitative gross mineral composition and the ratio of clay minerals in the pelitic fraction – using a D2 Phaser X-ray powder diffractometer (Bruker, Germany).The data obtained can be used for geological surveying and exploration of diamond-bearing placers in the Urals and in regions with a similar geological structure. It must be borne in mind that in the study area the described loess-like deposits do not have a direct connection with industrial placer diamond content.

Novel technique for the preparation and analysis of powder-based polished sections by automated optical mineralogy: Part 2 – Use of deep learning approach for transparent mineral detection

Automated reflected light optical microscopy represents an alternative and affordable technique compared to automated scanning electron microscopy for quantitative mineralogical analysis. Polished sections are the commonly used sample analysis format, and it is essential to obtain unbiased mineralogical quantification results from those. However, automated optical microscopy does not allow the detection of transparent minerals during reflected light analysis, as the reflectivity of the resin and these minerals is very similar.This work aims to propose an innovative way to automatically detect all particles and minerals, including transparent minerals, in polished sections with acrylic resin using reflected light optical imaging and a deep learning algorithm. To do so, several ore powders and standard mineral mixes were mounted into acrylic resin polished sections at two different particle sizes: < 1 mm and P80 ∼ 75 µm. Optical images of these polished sections were acquired with an automated reflected light optical microscope to train and test the deep learning algorithm to detect mineral particles. The results suggest that the deep learning algorithm easily detected all mineral particles in the acrylic resin matrix, allowing all minerals particles (including transparent minerals) to be well-differentiated under reflected light optical microscopy, and providing an unbiased mineralogical quantification.

Incomplete sulfide oxidation under sub-oxic conditions: Rates and aqueous sulfur speciation

The oxidative dissolution of sulfide minerals consumes oxygen and can generate redox gradients in mine wastes that affect the mobility of redox-sensitive solutes. However, the controls of oxygen depletion on sulfide reactivity and sulfur mobilization remain poorly constrained, complicating the long-term assessment of drainage quality dynamics. We investigated pyrite and Fe-rich sphalerite weathering using aqueous S speciation and quantitative mineralogical analyses under controlled, ambient versus sub-oxic, conditions at 6 < pH < 9. Titration assays revealed that oxidation rates for pyrite (up to 10−10 mol m−2 s−1) were higher than for sphalerite (up to 10−11 mol m−2 s−1) and, for both minerals, decreased by two orders-of-magnitude under sub-oxic (<50 ppm O2) conditions. Precipitation of secondary S-bearing minerals was restricted to elemental S, with no sulfate- or thiosulfate-salts detectable >0.01 wt%. Sulfate was the dominant aqueous S species produced in all experiments, but significant amounts of thiosulfate, tetrathionate, and sulfite were also found. These dissolved intermediate S species were abundant under both sub-oxic and oxic conditions, and broadly in line with known sulfide oxidation mechanisms, even though the weathering of pyrite produced several factors less incompletely oxidized S than that of sphalerite, under otherwise comparable conditions. This work shows that a range of intermediate S species may be produced even in low-reactivity conditions and may help optimize the management of such mine waste materials.

First results of electron microscopic study of sandstones of the Salikhovo Formation Vendian (The East-European platform)

For the first time, for the platform Vendian deposits, along with lithological and petrographic methods of studying rocks in sections and quantitative mineralogical analysis of the heavy fraction of concentrate, a study was carried out by scanning electron microscopy in thin sections. The use of scanning electron microscopy made it possible to significantly refine the mineral composition of rock-forming, secondary and accessory minerals. For the first time, it was indicated that the sandstones have their own minerals of rare earth elements (monazite and xenotime) and thorium (torite), and some geochemical features of REE concentrator minerals (apatite and zircon) have been identified. Additional information on the mineral and geochemical composition of the rocks of the Salikhov Formation can be used in the future to reconstruct the composition of the feeding provinces and the conditions for the formation of sedimentary paleobasins.

Novel technique for the preparation and analysis of powder-based polished sections by automated optical Mineralogy: Part 1 – Comparative study of representativity

Reflected optical microscopy is an affordable technique that can be used for automated quantitative mineralogical analysis. Polished sections are a common format used to analyze representative powdered mineral samples. The epoxy resin used to make polished sections for quantitative automated mineralogy is known to cause preferential sedimentation (or segregation) of the particles through the polished section. This phenomenon results in biased polished sections. Carbon-based resin preparation is now widely used to overcome this problem. This study presents a new resin for polished section preparation, acrylic resin, which can provide ready-to-analyze polished sections in less than three hours (instead of more than 10 h for other resins).This work investigated the effect of other polished section resin preparation protocols and compared them, including rheological measurements and automated optical microscopy analyses. The aim was to compare the polished section preparation techniques aiming at determining the technique which allows a reliable mineral abundance while not introducing a bias due to segregation in the polished sections. To do so, standard mineral powders were prepared using different pure opaque minerals at a calibrated size fraction of 20–75 μm. The results suggest that the rheological behavior of the fast-hardening acrylic resin allowed an accurate modal composition to be obtained while avoiding any preferential sedimentation of the particles compared to the other studied resins.

Automated quantitative mineralogy analysis reveals characteristics of Co occurrence in the Jinchang porphyry deposit, NE China

A critical and strategic metal, demand for cobalt (Co) has increased in recent years given its widespread use in new energy batteries. This has led to the need to search for new Co sources. Porphyry deposits have provided large quantities of Cu, Mo, Au and other critical elements such as Re, Se and Te. However, there is a paucity of research on the occurrence, enrichment mechanisms, and metallogenic potential of Co in porphyry deposits. The Palaeo-Pacific slab subduction related Jinchang Au deposit (∼80 t @ 8 g/t Au; Heilongjiang province, NE China) has recently been recognized as a cobalt-rich porphyry Au deposit. We conducted MapsMin (automated mineralogy analysis) on two bulk samples (10-c and Z1-13) from the J0 orebody of the Jinchang deposit to accurately determine the elemental content and Co distribution, and to definitively identify the Co minerals. MapsMin analysis revealed Co contents of 0.27% and 0.07% for samples 10-c and Z1-13, respectively. In addition, we conducted whole-rock geochemistry on ten powdered samples with inductively coupled plasma-atomic emission spectroscopy/mass spectrometry. The results showed Co ranges from 0.04 wt% to 0.29 wt% (average 0.1 wt%). We compared the results of MapsMin on bulk samples with inductively coupled plasma-atomic emission spectroscopy/mass spectrometry on powders, and confirmed the accuracy of the MapsMin analysis. The relative difference in the content of the main ore-forming elements Cu, Fe, Ti, and Co in the samples is less than 30%. MapsMin identified two Co minerals (siegenite and cobaltite) and revealed that there is an isomorphic Co-rich zone in pyrite rims. The good negative correlation between Co, (Co + Cu + Ni) and Fe in pyrite indicates that Co can enter the pyrite lattice through the substitution Co2++ (Cu2++Ni2+)↔ Fe2+. Crystal size distribution data shows that siegenite in 10-c was formed under two different conditions and petrographic evidence indicates that siegenite was the first to precipitate with chalcopyrite and pyrite in the Jinchang deposit. The formation of pyrite spans the entire mineralization process. During late-formed pyrite precipitation, Co-rich hydrothermal fluids were reinjected, causing a second precipitation of siegenite. High levels of Co entered the rim of pyrite, forming a Co-rich zone. Finally, a decrease of fO2 led to the precipitation of cobaltite. Mapsmin can provide a fast, accurate and reliable mineralogy data which can be used to constrain the contents and occurrences of cobalt and other metals, such as nickel, copper, gold, rare earth elements, etc.

Spatial variability of arsenic fractionation in an abandoned arsenic-containing mine: Insights into soil particle sizes and quantitative mineralogical analysis

Soil particle sizes and mineral phases play a major role in the migration of arsenic (As) in mine. In this study, soil As fractionation and mineralogical composition in different particle sizes soil at naturally mineralized and anthropogenically disturbed zones from an abandoned mine were comprehensively studied. The results showed that soil As contents in anthropogenically disturbed mining zone (MZ), processing zone (PZ), and smelting zone (SZ) were increased with decreasing of soil particle sizes. The contents of As in the fine soil particles (0.45–2 μm) reached to 850–4800 mg·kg−1, which mainly existed at readily soluble, specifically sorbed, and Al-oxide fractions, and contributed to 25.9–62.6 % of the total As contents in soil. Conversely, soil As contents in naturally mineralized zone (NZ) were decreased with decreasing of soil particle sizes and As was mainly accumulated in the coarse fraction of soil (0.075–2 mm). Despite the speciation of As in 0.075–2 mm soil mainly existed as residual fraction, the content of non-residual As fraction reached up to 1636 mg·kg−1, indicating a high potential risk of As in naturally mineralized soil. The utilization of scanning electron microscopy, fourier transform infrared spectroscopy combined with mineral liberation analyzer revealed that soil As in NZ and PZ was mainly retained by iron (hydrogen)oxide, while whereas the dominant host minerals for soil As in MZ and SZ were the surrounding rocks of calcite and the iron-rich silicate mineral biotite. Notably, both of the calcite and biotite exhibited high mineral liberation, which was partly contributed to a significant portion of mobile As fraction in MZ and SZ soil. The results suggested that the potential risks of soil As from SZ and MZ at abandoned mine, particularly in the fine soil particles, should be a prior concern.

1 Comparison of Ni Speciation Using Methods of Sequential Leaching and Quantitative Mineralogy for Workplace Aerosol at a Stainless Steel Plant

Abstract Based on epidemiological records of workers at Ni operations, regulatory guidelines often target specific Ni compounds for setting exposure limits. Thus, reliable methods of Ni speciation in airborne dust samples are required for effective monitoring of workplace exposure. In this study, Ni speciation of dust collected from a stainless steel operation was performed using a variety of methods: Zatka sequential leaching (original and modified protocols), soluble and insoluble Ni as described in ISO 15202, and quantitative mineralogy (QEMSCAN). Mineral characterization was also performed on bulk material collected from selected work areas at the plant. The quantitative mineralogical analysis determined that the Ni dust is composed of oxidic Ni (Ni in chromite and trevorite, &amp;gt; 80 % of the Ni in most samples) and metallic Ni (Ni-Fe alloy), and the results were validated against chemical assays and alternate methods of mineral characterization (Electron Probe Microanalysis, EPMA). In contrast, the original Zatka method erroneously identified soluble Ni as a major Ni contributor, whereas the modified Zatka method identified sulfidic Ni. The mineralogy identified ambient dust and grain sizes and textures of individual Ni compounds as potential factors that can affect leaching selectivity. Improving methods of sequential leaching is important because the resolution of quantitative mineralogical techniques diminishes at &amp;lt; 3 µm (respirable dust fraction). We recommend that quantitative mineralogy be performed in parallel with methods of sequential leaching to provide a robust system of characterization.

In situ calcite U–Pb geochronology of carbonate and clastic sedimentary rocks from the Canning Basin, Western Australia

In sedimentary basins, the determination of the absolute timing of deposition and diagenetic events is a challenging yet critical parameter necessary in the reconstruction of paleo-fluid evolution and burial histories. Here we demonstrate the practical application of in situ calcite U–Pb geochronology on core samples from the Olympic 1 well in the Canning Basin of Western Australia. Using quantitative mineralogy and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analytical techniques, we obtained an authigenic calcite U–Pb age of 469.7 ± 4.3 Ma for limestone in the Samphire Marsh Member of the Lower Ordovician Nambeet Formation. This precise depositional age can be independently verified using zircon thermal ionisation mass spectrometry U–Pb ages of 479.4 to 470.2 Ma determined on adjacent volcanic ash beds. Further geochronology studies on calcite cements from the Lower Ordovician Fly Flat Member sandstone from the Nambeet Formation returned a U–Pb age of 365.3 ± 5.8 Ma. This is the first study to place absolute age constraints on the diagenetic event that occluded the intergranular space in a sandstone reservoir. The calcite cementation age suggests that impairment of reservoir quality in the Fly Flat Member sandstone occurred in the Late Devonian, much earlier than major petroleum charge events in the Canning Basin. The calcite U–Pb geochronometer, when combined with complementary quantitative mineralogical analysis, can build direct temporal constraints on the depositional and diagenetic processes in both carbonate and clastic sedimentary rocks in basins worldwide.

Sample Preparation Biases in Automated Quantitative Mineralogical Analysis of Mine Wastes

Abstract Mineralogical information is becoming increasingly important for the interpretation and prediction of the long-term leaching behavior of mine waste rock and tailings, yet the collection of quantitative mineralogical data for these materials is complicated by biases introduced during sample preparation. Here, we present experiments with synthetic reference materials, soluble mineral (gypsum) and pulverized weathered waste rock samples to investigate potential artifacts that can be introduced during the preparation of granular sample specimen for quantitative mineralogical analysis. Our results show that, during epoxy-molding, particle segregation due to size is more important than that due to density, both of which can be effectively circumvented by cutting molds perpendicular to the orientation of settling. We also determine that sacrificing sample polish to avoid phase alteration need not impede phase attribution as long as surface roughness and slope are calibrated with sample-internal contrast references. Finally, bootstrapping analysis shows that variability in geometric and mineralogical particle parameters due to unresolved sample heterogeneity is small compared with other biases, even at particle numbers &amp;lt;25,000 at sizes &amp;gt;150 µm. Our results demonstrate the importance of quantifying potential sources of error during sample preparation in quantitative mineralogical studies on mine wastes.

Detrital zircon geochronology of the Permian Lower Shihezi Formation, northern Ordos Basin, China: time constraints for closing of the Palaeo-Asian Ocean

AbstractTemporal constraints on the closure of the eastern segment of the Palaeo-Asian Ocean along the northern margin of the North China Craton (NCC) remain unclear. As a part of the NCC, the sedimentation and tectonic evolution of the Late Palaeozoic Ordos Basin were closely related to the opening and closing of the Palaeo-Asian Ocean. We use petrology, quantitative mineralogical analysis, U–Pb geochronology and trace element signatures of detrital zircons of the Lower Shihezi Formation from two sections in the eastern north Ordos Basin and two sections in the western north Ordos Basin to reconstruct the sedimentary provenance and tectonic background of the northern Ordos Basin. The results show that the sediments of the western sections were mainly derived from the Yinshan orogenic belt and Alxa block, and that those in the eastern sections only came from the Yinshan orogenic belt. The trace element ratios in detrital zircons from the Late Palaeozoic sandstones indicate that the source areas were mainly subduction-related continental arcs, closely related to the continued subduction of the Palaeo-Asian Ocean in the Late Palaeozoic. Since the main Late Palaeozoic magmatic periods vary on the east and west sides of the northern margin of the Ordos Basin, two main collisions related to Palaeo-Asian Ocean closure are recorded. The collision on the west side occurred significantly earlier than that in the east. This study implies that the Palaeo-Asian Ocean began to subduct beneath the NCC in the Carboniferous and gradually closed from west to east thereafter.

LA‐ICP‐MS U–Pb dating of calcite cement in Upper Triassic tight‐gas sandstone reservoirs, western Sichuan Basin, SW China

AbstractThe absolute timing of carbonate cement formations can provide insights into porosity evolution and hydrocarbon accumulation in reservoirs. In this study, scanning electron microscopy‐based cathodoluminescence (SEM‐CL), quantitative mineralogical analysis and laser ablation inductively coupled plasma‐mass spectrometry U–Pb dating were performed on calcite cements from sandstones in the fourth member of the Upper Triassic Xujiahe Formation in the western Sichuan Basin. Two samples yielded U–Pb ages of 149.5 ± 31.1 Ma and 190.0 ± 180.5 Ma (2σ), suggesting late diagenetic precipitation of calcite cements. The backscattered electron and SEM‐CL images indicated that the cements precipitated after feldspar dissolution. Combined with palaeo‐temperature evolution, these results suggest that the timing of calcite cement precipitation occurred between the Late Jurassic to Early Cretaceous. Rapid accumulation of sediment in the western basin in response to the Yanshanian Orogeny may have caused stratum overpressure, resulting in geofluid activity and calcite precipitation in the Xu4 sandstone.

Experimental Simulation of Burial Diagenesis and Subsequent 2D-3D Characterization of Sandstone Reservoir Quality

Characterization of deeply buried sandstones and their reservoir quality is of paramount importance for exploring, developing, and subsurface storage of energy resources. High reservoir quality in deeply buried sandstones is commonly correlated with the occurrence of grain coatings that inhibit quartz cementation. The development of reliable models that can predict reservoir quality relies on incorporating quantitative understanding of these diagenetic processes. Hydrothermal experiments simulating burial diagenesis were integrated with multi-scale X-ray tomography to quantify the 3-dimensional evolution of grain coating volume and porosity with increasing temperature; while microscopic and automated quantitative mineralogy analysis were used to track the associated mineralogical alterations. To simulate reservoir evolution, sandstone samples from the Lower Jurassic Cook Formation (Oseberg Field, 30/6-17R, Norway) were exposed to a silica supersaturated Na2CO3 (0.1 M) solution for up to 360 h at temperatures of 100–250°C. The experimental results show the main porosity and permeability reduction window is associated with pore-filling kaolinite, and lies between 150 and 200°C, above which little change occurs. Volumetric increases in grain coating start to occur at ∼150°C through precipitation of authigenic chlorite, and continue to 250°C, irrespective of the experimental duration. Together with preexisting siderite coatings, the newly precipitated chlorite prevents the loss of reservoir quality by inhibiting quartz overgrowth development. Pore flow simulations based on the observed temperature-dependent 3-dimensional pore networks allow us to characterize pore-throat and permeability evolution and gain quantitative understanding of the impact of diagenetic overprinting on deeply buried sandstone reservoirs.

Gas chromatography-mass spectrometry and scanning electron microscopy with energy-dispersive radiograph analysis of biodeteriorative metabolites produced by Aspergillus species

Background and objectives Fungal deterioration of cultural heritage is a major problem that causes physical and chemical damage as well as esthetic alteration. In the current research, fungal species that exist on a brick sample obtained from Egyptian historical places were isolated and identified. Moreover, various metabolic products produced by the isolated fungal species were detected, which may play an important role in the deterioration of many historical buildings.Materials and methods Various fungi existing on brick samples collected from an Egyptian historical place were identified phenotypically and then confirmed molecularly based on the 18 S rDNA technique. The metabolites found in the chloroform extract of the isolated fungi were detected by gas chromatography-mass spectrometry. Quantitative mineralogical analysis of the deteriorated brick was studied by radiograph diffraction. Moreover, scanning electron microscopy-energy-dispersive radiograph was employed to identify the mineral compositions and surface structural morphology of the collected brick sample.Results and conclusion Three fungi showed the highest occurrence and were identified as Aspergillus niger, Aspergillus terreus, and Aspergillus flavus. The metabolites found in the chloroform extract of the three fungi were detected by gas chromatography-mass spectrometry, which showed that 5­octadecene, (E) was common among A. niger, A. terreus, and A. flavus; nonadecane and E­15­heptadecenal were common between A. niger and A. flavus; α­cadinol, tetradecane, and hexadecane were common between A. niger and A. terreus; and trans­caryophyllene, α­humulene, tau­muurolol, and octadecane were common between A. terreus and A. flavus. In addition, there was a presence of other hydrocarbons and various organic acid esters that play a vital role in the brick deterioration. Moreover, radiograph diffraction and scanning electron microscopy-energy-dispersive radiograph results showed that the brick sample contains Si, Fe, Ca, and Al, with small amounts of Na, Mg, and Cl. The fungal hyphae penetrating the brick sample were also detected. Our results demonstrate that fungi existence could result in physical deterioration by extending their hyphae through the brick pores resulting in stress. Fungi could also lead to chemical deterioration due to the production of different acids and acid derivatives that cause the brick demineralization via chelation of various metal. In addition, the production of various aliphatic and aromatic hydrocarbons by the fungi could play an important role in the deterioration process.

Characterization of Mine Waste from a Former Pb–Zn Mining Site: Reactivity of Minerals During Sequential Extractions

An integrated mineralogical and chemical characterization approach was applied to different types of mine waste collected from the ancient Pb–Zn mining area of Plombières. The combination of different methods to determine (pseudo-)total element concentrations, sequential extractions, and quantitative mineralogical analysis provided detailed information on the reactivity of minerals in the waste, as well as the associated metal(loid) release under different experimental conditions. Lithium borate (LiBO2) fusion was not suited to determine total metal(loid) concentrations in the investigated mine waste samples, due to the incomplete dissolution of the samples, and the volatilization of As and Cd during the fusion. Because some elements were below detection limit of X-ray fluorescence spectrometry (e.g., Cd), aqua regia digestion was useful to complement the chemical sample characterization, bearing in mind that only pseudo-total concentrations could be determined. Galena (PbS) and its alteration products, cerussite and anglesite (PbSO4), were the main lead minerals associated with the mining waste. Because of the high cerussite (PbCO3) content of the investigated samples (2–5 wt%), Pb not only shows the highest potential for recovery from the mining waste, but it also poses the highest environmental and human health risk. Zinc minerals showed a lower reactivity towards the BCR sequential extraction (sphalerite, ZnS) or were less abundant (willemite, Zn2SiO4). Quantitative XRD analysis allowed for better evaluation of the incomplete dissolution of some minerals, improving the interpretation of the sequential extraction results.

Comparison of quantitative mineralogy and sequential leaching for characterization of Ni in workplace dust collected at a stainless steel operation

Based on epidemiological records of workers at Ni operations, regulatory guidelines commonly target specific Ni compounds for setting exposure limits. Thus, reliable methods of Ni speciation in airborne dust samples are required for effective monitoring of workplace exposure. Zatka sequential leaching has been routinely performed industry-wide since the 1990s for characterization of Ni in dust samples; however, limitations related to leaching kinetics have been identified, and optimization of the methodology is required to improve accuracy of data. In this study, Ni characterization of dust collected from a stainless steel operation was performed using Zatka sequential leaching (original and modified protocols) and quantitative mineralogy (QEMSCAN), a method novel to the field of industrial hygiene. Mineral analysis was also performed on bulk material collected from selected work areas at the plant. The results are compared with the objective of identifying opportunities to optimize the methods for characterizing dust that is unique to stainless steel manufacturing. The quantitative mineralogical analysis determined that the Ni dust is composed of oxidic Ni (chromite and trevorite, >80% of the Ni in most samples) and metallic Ni (Ni-Fe alloy), and the results were validated against chemical assays and alternate methods of mineral characterization. In contrast, the original Zatka method erroneously identified soluble Ni as a major Ni contributor, whereas the modified Zatka method identified sulfidic Ni. The mineralogy identified Ni-barren dust and grain sizes and liberation of individual Ni compounds as potential factors that can affect leaching selectivity. Clearly, for any sequential leaching method to be useful for these workplaces, they should be optimized by including reference materials that are representative of Ni substances present at stainless steel operations (chromite, trevorite, and Ni-Fe alloy). Improving methods of sequential leaching is important because the resolution of quantitative mineralogical techniques diminishes at <3 μm (respirable dust fraction). We recommend that quantitative mineralogy be performed in parallel with methods of sequential leaching to provide a robust system of characterization.

Monitoring of Lithium Contents in Lithium Ores and Concentrate-Assessment Using X-ray Diffraction (XRD)

Lithium plays an increasing role in battery applications, but is also used in ceramics and other chemical applications. Therefore, a higher demand can be expected for the coming years. Lithium occurs in nature mainly in different mineralizations but also in large salt lakes in dry areas. As lithium cannot normally be analyzed using XRF-techniques (XRF = X-ray Fluorescence), the element must be analyzed by time consuming wet chemical treatment techniques. This paper concentrates on XRD techniques for the quantitative analysis of lithium minerals and the resulting recalculation using additional statistical methods of the lithium contents. Many lithium containing ores and concentrates are rather simple in mineralogical composition and are often based on binary mineral assemblages. Using these compositions in binary and ternary mixtures of lithium minerals, such as spodumene, amblygonite, lepidolite, zinnwaldite, petalite and triphylite, a quantification of mineral content can be made. The recalculation of lithium content from quantitative mineralogical analysis leads to a fast and reliable lithium determination in the ores and concentrates. The techniques used for the characterization were quantitative mineralogy by the Rietveld method for determining the quantitative mineral compositions and statistical calculations using additional methods such as partial least square regression (PLSR) and cluster analysis methods to predict additional parameters, like quality, of the samples. The statistical calculations and calibration techniques makes it especially possible to quantify reliable and fast. Samples and concentrates from different lithium deposits and occurrences around the world were used for these investigations. Using the proposed XRD method, detection limits of less than 1% of mineral and, therefore down to 0.1% lithium oxide, can be reached. Case studies from a hard rock lithium deposit will demonstrate the value of mineralogical monitoring during mining and the different processing steps. Additional, more complex considerations for the analysis of lithium samples from salt lake brines are included and will be discussed.

Provenance analysis of sediments in the south-east Aegean during the Upper Quaternary: a composite approach based on bulk and clay mineralogy and geochemistry

AbstractSediments from the ST5 deep-sea bottom core collected from the south-east Aegean Sea between Symi and Tilos islands, Greece, were examined by quantitative mineralogical analysis and geochemical analysis to infer provenance and palaeoenvironmental control over sediment deposition. The mineralogical composition comprises carbonates (mainly calcite and Mg-calcite), quartz, feldspars, serpentine, amphibole and clay minerals. Chlorite is the most abundant clay mineral, whereas smectite and illite are less abundant than in the sediments in the south-west Aegean and the Cretan Sea. Semi-quantitative analysis of clay minerals from oriented clay fractions overestimates significantly the smectite content and underestimates the abundances of illite, chlorite and kaolinite. The studied sediments are enriched in MgO, Ni and Cr, which decrease in abundance with decreasing depth, following the distribution of serpentine. By contrast, the abundances of SiO2, Al2O3, Fe2O3, Na2O and K2O increase upcore. The regional S1 sapropel horizon is enriched in V and Co and has considerably greater Ba/Al ratios than the remaining sequence. The mineralogical and geochemical relationships indicate a strong ultrabasic influence, probably from the Marmaris ophiolite in the Lycian nappes. The clay mineral distribution suggests that the smectite was mainly of volcanogenic origin, the illite was supplied by the nearby landmasses of west Anatolia and the islands of Rhodes, Tilos and Symi and the contribution from the south-east Mediterranean was limited or totally lacking. The combined use of the mineralogical and geochemical analysis of bulk sediments rather than the clay fractions is not only extremely useful in tracing sediment provenance in relatively closed basins, but it also enables a more realistic assessment of the importance of water circulation patterns on sedimentation processes in such environments.

Quantitative mineralogical analysis of clay-containing materials using ATR-FT-IR spectroscopy with PLS method.

A universal method for quantitative analysis of clay components, in terms of mineral composition, using ATR-FT-IR spectroscopy (in the mid-IR and far-IR regions) combined with partial least squares (PLS) regression technique (ATR-FT-IR-PLS) is reported. For the PLS method development, altogether 222 samples covering natural clay sources and various archaeological/cultural heritage artefacts were used as calibration and validation standards. This is the largest calibration set used for creating an ATR-FT-IR-PLS method for clay minerals. The quantitative compositions of these standards containing combinations of altogether 29 minerals for the PLS method were determined using XRD analysis. The developed ATR-FT-IR with PLS method is quick and easy to use, and enables analysis of very small sample amounts (down to a few mg). This is very important when working with samples from archaeological and cultural heritage objects. The developed ATR-FT-IR-PLS method enables quantifying the contents of 7 main classes of minerals in different clays with a root mean square error of prediction (RMSEP) ranging from 0.9 to 5.1 g/100g. This means that in some cases, depending also on the content of the mineral in the sample, the accuracy is at a semiquantitative level. This quantitative method was successfully applied to 11 cultural heritage case-study samples.

Content of rare earth elements in basalt aggregate from Winna Góra, Poland

Seek for new Rare Earth Elements (REE) sources encourage looking for easily available sources located in Europe. REE in evolved magmatic systems are predominantly associated with alkali environments. Therefore, it was decided to identify the content of REE in alkali igneous rocks of the Winna Góra basalt quarry located in Lower Silesia, Poland. In this study, a commercially available basalt aggregate from Winna Góra deposit located in the south-western part of Poland near Jawornik was examined for REE content. Mineral content and chemical composition were examined with a light microscope, XRD and XRF, whereas trace element content was measured with the ICP-MS technique. A new method of sample preparation for the purpose of REE identification in basalt aggregate based on pressure microwave mineralisation was developed. Mineral composition and TAS diagram classify aggregate as tephrite. The mineral composition of samples reflects typical mafic and ultramafic rocks. Quantitative mineralogical analysis by the Rietveld method showed that the main minerals are anorthite (46.7%) and augite (37.4%) with a minor content of forsterite (7.5%), nepheline (7.4%) and apatite below 1%. The total content of REE does not exceed 132 ppm. Chondrite normalised curves show the highest concentration of La and Pr. In the case of HREE, the majority of elements (Eu, Tb, Dy, Ho, Er, Yb) concentrations were below 1 ppm, a Tm and Lu were not detected. The low enrichment in HREE was also reflected in La/Gd ratios. Obtained results are comparable to the REE contents in the western part of the Cenozoic European Volcanic Province.