X-ray Fluorescence Method Research Articles

BOTTOM SEDIMENTS OF SURFACE WATERCOURSES OF THE MALMYZHSKY MOUNTAIN RANGE

X-ray fluorescence, electron microscopic, sedimentation analyses and laser diffractometry methods were used to study the composition of bottom sediments of surface watercourses of the Malmyzhskaya Ridge section allocated for the construction of a mining and processing plant (Khabarovsk region, Russia). It is established that the bottom sediments of the coastal zone of the watercourses of the studied area are characterized by a similar gross composition and physical and chemical properties (pH, solid phase density, total carbon content, wetting edge angle CAW). Th ey are mainly represented by fine earth with a high proportion of suspended sediments, in which the fraction of coarse silt prevails (particle size <2,0 mm, <0,1 mm and 0,01-0,05 mm, respectively). It is shown that deforestation in the sources of watercourses accompanied by soil erosion leads to a significant increase in the dispersion of sediments (an increase in the proportion of suspended sediments up to 90%) in the upstream. Downstream, with the distance from the felling sites, the infl uence of deforestation on the dispersion of deposits fades. Th e content of suspended sediment is reduced to values characteristic of watercourses in the catchment area of which deforestation has not been carried out. Significant microaggregation of suspended sediments of watercourses was revealed, the participation of microbiota (testate amoebas of xenosome taxa, diatoms and Fereducing bacteria) in the formation of microaggregates was diagnosed. Th e latter are involved in the formation of vivianite on the surface of ferruginous-clay microaggregates with an increased content of phosphates after fires. The mechanism of formation of toroidal microforms of vaterite in bottom sediments with the participation of cyanobacteria of the Spirulinaceae family is proposed.

Synthesis of Ti-Ni and Zr-Ni Core–Shell Particles Using Galvanic Replacement

This article focuses on the galvanic replacement synthesis of Ti-Ni and Zr-Ni metal systems with a “core-shell” structure, which are potential precursors for intermetallics. The authors defined effective synthesis parameters and formation features of polymetallic systems characterized by granulometric, phase, and elemental composition. X-ray fluorescence and X-ray phase analysis methods showed that the deposition of nickel on dispersed titanium and zirconium leads to the production of test samples with phase composition representing a mechanical mixture of Ni and Ti, and Ni and Zr. The method of X-ray fluorescence analysis showed that the presence of hydrofluoric acid with a 0.5-1.5 M concentration results in the formation of fixed quantitative ratios of elements in the precipitate, which allows the quantitative composition of dispersed systems “titanium-nickel” and “zirconium-nickel” to be regulated within a relatively wide range. Scanning electron microscopy proved that all synthesized systems are characterized by a highly porous structure that follows the titanium and zirconium particle surface contour and the presence of spherical nanoscale subunits on the formed particle surface.

Thermal Decomposition of Siderite and Characterization of the Decomposition Products under O2 and CO2 Atmospheres

Siderite (FeCO3) is an iron-bearing carbonate mineral that is the most abundant sedimentary iron formation on Earth. Mineralogical alteration of four siderite samples annealed at temperatures 200 °C, 300 °C, 400 °C, 500 °C, 750 °C, and 1000 °C in an O2 and a CO2 atmosphere were investigated using such tools as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), the X-ray fluorescence (XRF) method, differential scanning calorimetry and thermogravimetric analysis (DSC/TGA), and Mössbauer spectroscopy measurements. The decomposition of three siderite samples with similar iron content in the oxygen atmosphere took place in the temperature range of 340–607 °C. This process begins at approximately ~100 °C higher under a reducing atmosphere, but it is completed just above 600 °C, which is a temperature comparable to decomposition in an oxidizing atmosphere. These processes are shifted toward higher temperatures for the fourth sample with the lowest iron but the highest magnesium content. Magnetite, hematite, and maghemite are products of siderite decomposition after annealing in the oxygen atmosphere in the temperature range 300–500 °C, whereas hematite is the main component of the sample detected after annealing at 750 °C and 1000 °C. Magnetite is the main product of siderite decomposition under the CO2 atmosphere. However, hematite, maghemite, wüstite, and olivine were also present in the samples after annealing above 500 °C in this atmosphere.

New quantification approaches for total-reflection X-ray fluorescence analysis of micro-sized samples: Apatite case study

Sensitive methods for quantitative elemental analysis of micro-sized samples are limited. In this study, total-reflection X-ray fluorescence (TXRF) method was applied as fast and cost-efficient method to apatite microcrystals. In situ acid digestion based on direct treatment of single crystal onto the carrier was used as sample preparation strategy. Since the internal standard addition is complicated in the case of micro-sized samples, new quantification approaches based on external calibration for TXRF analysis of apatite were offered. An experimental design was created for apatite samples with a differentiation of specimen masses from 1.0 to 100 μg to find patterns in the spectral information. A workflow has been proposed for analyzing apatite crystals of various sizes (100, 500, 1000 µm) with TXRF based on an external calibration using an apatite powder sample as a standard and normalizing the spectra to the P-Kα and Mo-Kα peaks. The conditions of the workflow should be the following: Ca/P ratio is in a range between 19 and 23, and a dead time value does not exceed 4.0 %. The dead time value was used as a main factor of quantification, when calibration sample should match the unknown sample. Limit of detection values of the proposed method are from 1.0 to 100 μg/g depending on the crystal size and element of interest. Validation of the TXRF method was performed by analysis of Durango and McClure apatite samples. Comparison of TXRF results with laser ablation inductively coupled plasma mass spectrometry data showed the good agreement between two methods.

Influence of anthropogenic waste of different genesis on properties of fine-grained concrete

Introduction. The growing amount of stored waste from TPPs has a negative impact on the environmental and economic situation in Russia. The content of ash dumps leads to pollution of nearby areas and increase in energy prices. To solve this problem, it is proposed to use TPP waste as a component of solutions. Materials and methods. The equipment on which the experiment was performed is listed. For the test of compressive strength, the press TP-1-350 Universal was used. For the test of flexural strength, MII-100 machine was used. Specific surface area of TPP waste was determined on PSKh-12 device. The samples gained the strength in the chamber of normal hardening. The chemical composition of TPP waste was determined by the X-ray fluorescent method. Results. The experimental data on the strength of specimens with the replacement of part of the cement by waste thermal power plants of different genesis are presented. The part of the samples were cured under normal conditions, and part was subjected to heat and humidity treatment. Specific cement consumption per unit of compressive and flexural strength was calculated. Compressive strength of mortars with replacement of 20% of cement by Kuznetsky TPP ash makes it possible to obtain samples with strength by 8% less than the control sample under normal curing conditions. The use of acid ash from Omsk TPP and Kuznetsky TPP under heat and moisture treatment makes it possible to obtain the samples with compressive strength higher than the control sample up to 13%. The introduction of 30 % of the basic ash from Novosibirsk TPP instead of cement allows to obtain samples with compressive strength up to 46,55 MPa. The calculation of specific consumption of cement per unit strength showed that the use of the proposed compositions is more cost-effective than the control ashless sample up to 30%. Discussion and conclusions. It has been proved that replacement of up to 30% of cement by TPP wastes makes it possible to obtain mortars with strength not lower than that of the control cement sample. Depending on curing conditions and the type of used TPP waste it is possible to receive samples with compressive strength up to 46,55 MPa and bending strength up to 9,31 MPa. It was found that the use of heat and moisture treatment for the samples using basic ash does not give an increase in strength, compared to acidic ash.

Utilizing X-ray fluorescence (XRF) method to evaluate the content of metal elements in soil and their effects on the total phenolic and flavonoid contents of some medicinal plants.

Soil factors, especially metal elements in the soil, play a significant role in forming and accumulating secondary metabolites, which determine the medicinal properties of medicinal herbs. In this study, the concentrations of some metal elements (K, Mn, Fe, Cu, Zn, and Cr) in Cam Mountain and Tinh Bien Town, An Giang Province, Vietnam, were determined using the XRF method. We simultaneously determined the total phenolic and flavonoid content of some medicinal herbs collected from the collected soil sample areas, thereby assessing the influence of these elements on the formation of secondary metabolites in medicinal plants. The results showed that K, Mn, and Cr were mainly concentrated in the topsoil and transition layers; Fe and Cu elements tended to concentrate in the transition layer and the subsoil when surveying the soil profile. K, Mn, Cu, and Cr concentrations were more focused in Tinh Bien area, while Fe and Zn had higher concentrations at Cam Mountain. Additionally, results from evaluating the relationship between the content of the elements in the soil and the content of two active compounds also showed the correlation regression model between Zn and flavonoid expression by level 4 at the 5% significance level. Thus, the nonlinear model is suitable for evaluating the relationship between the content of metal elements in the soil and the active compound in medicinal plants.

Efficient and cost-effective determination of Cr(VI) ions using immobilized 4,5-dihydroxynaphthalene-2,7-disulfonic acid disodium salt dihydrate: a novel analytical reagent with high selectivity and sensitivity

ABSTRACT The determination of Cr(VI) ions in real-world samples is of utmost importance due to the critical role it plays in assessing and monitoring the levels of Cr(VI) contamination in water. The present study introduces a time-saving, cost-effective, selective, highly efficient and eco-friendly analytical reagent to detect Cr(VI) ions. This study presents fabrication of immobilised 4,5-dihydroxynaphthalene-2,7-disulfonic acid disodium salt dihydrate (DHNDSADNa) on a polyethylene-polyamine polyacrylonitrile (PPA) matrix for the determination of Cr(VI) ions using X-ray fluorescence, spectroscopic analysis and potentiodynamic titration methods. The findings revealed that the immobilised DHNDSADNa on the PPA matrix is a highly selective, accurate, easily regenerable, and rapid analytical reagent for the determination of Cr(VI) ions. The DHNDSADNa-anchored PPA framework demonstrated distinctive spectroscopic signals at 460 nm and 590 nm for the reagent and its complex with Cr(VI) ions, respectively. The detection limit for Cr(VI) ions was found to be 2 μg/mL, which is lower than that of DHNDSADNa in solution. Furthermore, the reagent exhibited high selectivity and efficiency for Cr(VI) ions even in the presence of other ions such as Co(II), Ni(II), Al(III), Fe(II), Ti(IV), Zr(IV), Ta(V), Mn(II), and W(VI). Last but not least, the immobilised DHNDSADNa on the PPA matrix exhibits superior analytical characteristics compared to previously utilised methods, making it a promising tool for various applications in medicine, pharmacology, biology, chemistry, and engineering.

The Characterization of Used Cooking Oil as a Raw Material to Produce Biofuel Using CoMo/Bottom Ash with Catalytic Cracking Process

The research conducted in the study of converting used cooking oil into biofuel is done using the catalytic cracking technology process. Used cooking oil, a byproduct of household cooking oil waste, has the potential to be turned into energy. However, its utilization is not yet optimal, and it often just becomes household waste. Therefore, in this study, used cooking oil is used to produce biofuel. The CoMo/Bottom ash catalyst is used to accelerate the biofuel production process. The characteristics of the used cooking oil were analyzed using the Gas Chromatography-Mass Spectrometry (GC-MS) method, which revealed that the oil contained 2.50% linoleic acid, 0.54% myristic acid, and 22.11% palmitic acid, which are some of the main ingredients for making biofuel. The physical properties of the used cooking oil were found to be a viscosity of 3.81 mPa.s, a density of 0.93 g/ml, a refractive index of 1.43, and a flash point of 241°C. Meanwhile, the characteristics of the coal bottom ash used as a catalyst were analyzed using the X-Ray Fluorescence or X-ray diffraction method. It was found to contain 48.61% silicon dioxide (SiO2), 13.97% aluminum oxide (Al2O3), 4.40% iron (III) oxide (Fe2O3), 2.92% calcium oxide (CaO), 0.82% magnesium oxide (MgO), and 0.48% potassium oxide (K2O). The characteristics of the used cooking oil and the coal bottom ash that were analyzed show that used cooking oil can be used as raw material for biofuel production, while coal bottom ash can be used as a catalyst.

Pozzolanic properties of marble industrial waste and its used in concrete

Concrete needs to use alternative materials to reduce cement content to limit the effect of carbon emissions. Marble dust as a waste of the marble industry has very fine grains. X-Ray Fluorescence (X-RF) method was conducted to determine the mineral properties of marble dust. Marble dust was found to contain 98.62% Calcium Oxide (CaO), 0.17% Sulfur Trioxide (SO3) and some elements in small levels. To determine the impact of marble dust on the mechanical characteristics of concrete, an experimental study was conducted. Test specimens were made with four different levels of marble dust, namely 0%, 5%, 10%, and 15%. The experimental results showed that the optimum usage was 6.62% by weight of cement which gave the advantage of increasing the compressive strength of concrete by 11.77%.

THE EFFECT OF THE TYPE AND CONTENT OF CARBONATES ON THE CHARACTERISTICS OF POROSITY OF CERAMIC MEMBRANES

The main issue considered in the work is the creation of a matrix for ceramic membranes, which would be distinguished by low cost and high porosity. In order to reduce the cost of ceramic membranes, a widespread approach was chosen, which is powerfully used by many researchers, namely the use of natural minerals - kaolin and saponite - as the main components of the matrix. Carbonates were used as pore generating agents to achieve the required porosity value. Three series of ceramic membranes (CM) differing in chemical composition were synthesized in the work: KP1, KP2, and KP3 series. The main composition of CM includes: kaolin, saponite, sodium silicate and carbonates. The effect of the type and amount of carbonates (CaCO3, NH4HCO3, (NH4)2CO3) as pore generating agents on the formation of the porous structure of the samples was studied. The type and content of carbonates varied in different samples from 8 wt% up to 40 wt%. The dry pressing method using pressure equivalent to 8 tons and 15 tons was used to form ceramic membranes. The main parameters by which the properties of ceramic membranes were evaluated: water absorption, total and open porosity. Standard methods were used to determine these parameters for synthesized samples. The chemical composition of the dry mixture of the ceramic membrane, for which the porosity is the maximum in the series of manufactured samples, was established. It was established that the addition of calcium carbonate components to the dry mixture increases the porosity of ceramic membranes and water absorption. The chemical composition of a ceramic membrane sample with the best indicators of total and open porosity in the KP2 series is given. The chemical and phase composition of samples of the KP2 series, as well as their structural and adsorption characteristics, were investigated by X-ray fluorescence and diffraction methods of analysis and low-temperature nitrogen adsorption-desorption. The effect of the addition of silicon carbide on the characteristics of the porosity of the samples was determined.

Chemical analysis and filtration efficiency of ceramic point-of-use water filters

Ceramic water filters (CWFs) are globally employed as a point-of-use water treatment technology. Although, there are no standards to regulate the use of these CWFs in developing countries, they are gaining acceptability for domestic water treatment. This study sought to assess and compare the efficiency of commercially available types of CWFs and to propose a consumer selection guide for the purchase and use of CWFs. The CWFs selected for the study were, Ball filter with activated carbon (BF + AC), Candle filter (CF), and Pot filter (PFcs) coated with colloidal silver. The elemental and mineral oxide composition of the selected CWFs were analysed with x-ray fluorescence method. Furthermore, the raw unfiltered water (from three different common sources), and the filtrates obtained with the CWFs were analysed for their physicochemical, metal ion removability, and microbial correction. The x-ray fluorescence analysis indicated that Al2O3 and SiO2 were the major mineral oxide compositions of the selected CWFs. These metal oxides were present in varying concentrations. The CWFs showed turbidity reduction of 74.28–99.40%, Mn and Fe reduction of 54.04–98.48% and 48.82–97.50% respectively. In addition, the total coliform reduction by the selected CWFs ranged from 2.31 to 76.97%. It was therefore observed from the results that, the efficiency of commercially available CWFs varied in the order BF + AC > CF > PFcs. BF + AC was the most efficient in both physicochemical and microbial correction of all water sources. CWF selection guide for consumers based on different sources of water which considered the physicochemical parameters, biological parameters and Water Quality Index was discussed. This has an implication for regulation and standardization of CWFs.

Relevance of Soil Heavy Metal XRF Screening for Quality and Landscaping of Public Playgrounds.

Heavy metals have become widespread urban pollutants, exposing vulnerable age groups such as children to potential risk. Specialists need feasible approaches that can routinely assist them in customizing options for sustainable and safer urban playgrounds. The aim of this research was to explore the practical relevance of the X-ray Fluorescence (XRF) method from the perspective of landscaping specialists, and the practical significance of screening for those heavy metals that currently present elevated levels across urban environments Europe-wide. Soil samples from six public children's playgrounds of different typologies from Cluj-Napoca, Romania, were analyzed. The results indicated that this method was sensitive to identifying thresholds stipulated in legislation for the screened elements (V, Cr, Mn, Ni, Cu, Zn, As, and Pb). Coupled with the calculation of pollution indexes, this method can serve as a quick orientation in landscaping options for urban playgrounds. The pollution load index (PLI) for the screened metals showed that three sites displayed baseline pollution with incipient deterioration in soil quality (PLI = 1.01-1.51). The highest contribution to the PLI among the screened elements, depending on the site, was due to Zn, Pb, As, and Mn. The average levels of the detected heavy metals were within admissible limits according to national legislation. Implementable protocols addressed to different categories of specialists could help to transition towards safer playgrounds and more research on accurate cost-effective procedures to overcome the limitations of existing approaches is currently needed.

Role of TiO2 addition on recycling of TV screen waste glasses: Experimental and theoretical studies on structure and radiation attenuation properties

Using the powder metallurgy, TiO2-doped TV screen glass ceramic samples were prepared with TiO2 concentrations of 0 (S-TV), 10 (S-TV/Ti10), and 20 (S-TV/Ti20) wt%. The TV screen glass was collected from a damaged TV's CRT. The fabricated materials were investigated for their physical, structural, and radiation-shielding attributes. The chemical composition of the prepared glasses was analysed with the aid of the X-ray fluorescence (XRF) method. The crystalline phase and microstructure of the glass ceramics were studied through the X-ray diffraction (XRD) method and scanning electron microscope (SEM), respectively. The density and Vickers hardness of the sample were determined by the Archimedes method and a micro hardness tester, respectively. The absorption parameters of electrons, protons, alpha particles, carbon ions, fast neutrons, and thermal neutron were calculated from various software and analytic expressions. The XRD spectra of the samples showed the presence of distinct crystalline peaks associated with TiO2, SiO2, and Ba2SiO4. The SEM images revealed that crystalline structures nucleated and increased with coarser crystalline grains when the amount of TiO2 was increased. The densities of the glass ceramics were 2.525, 2.546, and 2.285 g/cm3 for the S-TV, S-TV/Ti10, and S-TV/Ti20 samples, respectively while the corresponding Vickers hardness values were 495, 540, and 578 HV. The projected range of electrons, protons, alpha particles, and heavy carbon ions were within the limits 2.78–32182.18 μm, 0.215–1400 μm, 0.154–130.54 μm, and 0.053–14.10 μm in S-TV, 2.76–31991.36 μm, 0.205–1320 μm, 0.147–122.05 μm, and 0.049–13.11 μm in S-TV/Ti10, and 2.84–32824.95 μm, 0.212–1360 μm, 0.151–125.55 μm, and 0.051–13.45 μm in S-TV/Ti20, respectively. Among the three samples, S-TV was the best thermal neutron absorber, while S-TV/Ti10 is most effective in slowing down fast neutrons. The optimum TiO2 doping content for enhancing the charged particle and fast neutron moderating abilities of TV screens is 10 wt%.

Hydrometallurgical refining of metallurgical silicon

The paper presents the results of refining silicon of metallurgical grades based on leaching of impurities with inorganic acids. Silicon samples were studied by metallographic and X-ray fluorescent methods of analysis, as well as X-ray spectral microanalysis. To improve the quality of this alloying element, we carried out experimental work on its hydrometallurgical purification with solutions of various acids (10 % H2SO4 , HCl, HNO3 , 4 % HF) and their mixtures. Values of changes in the Gibbs energy were calculated for reactions of interaction with reagents of the main impurity inclusions recorded in the studied silicon samples (FeSi2 , Fe2Si, FeSi, AlFeSi, AlFeSi2 , Al3FeSi2 , FeSi2Ti, FeAlTiSi, TiSi2 , Ca2Si). The experiments were carried out on silicon samples with a particle size of –200 μm with constant stirring by a magnetic stirrer at a temperature of 60 °С, duration 1 h and L:S = 5:1. Determination of concentration of the impurity elements in the solution after leaching was made by the atomic emission method of analysis. When hydrofluoric acid is used as a solvent, the best results are obtained for purification of iron, aluminum, and titanium (concentration in solution, mg/dm3, respectively: 2380, 831, 145). The maximum concentration of calcium in the solution (147 mg/dm3 ) was achieved by hydrochloric acid treatment of fine silicon. The most effective for transferring impurities into solution is a mixture of sulfuric and hydrofluoric acids at a ratio of 1:1. Using a mixture of H2SO4 and HCl as a solvent (at a ratio of 1:3) made it possible to achieve sufficiently high mass concentrations of impurity elements in the leaching solution. The degree of silicon purification from iron was 33.32 %, aluminum – 54.64 %, calcium – 65.77 %, titanium – 15.64 %.

CHEMICAL PROPERTIES OF SOIL IN QUARTZ SAND MINING IN RIAU ISLANDS PRE-RECLAMATION ACTIVITIES

It is necessary to figure out the chemical characteristic of soil in the pre-reclaimed land of quartz sand mines in order to find the appropriate and optimal reclamation method applied. A laboratory analysis is then conducted to determine the impact of the causes of decreased soil fertility. This research is conducted at PT. X Kepulauan Riau. The method used for soil sampling is FAO (1976) at a depth of 0-30 cm, with a total of 4 samples, namely sample A, B, C, and D. Sample A, B, and C are used in the XRF (X-Ray Fluorescence) method to determine the chemical compounds contained in the soil, while sample D is used for analyzing the soil chemical characteristic to determine the nutrients contained in the soil. Based on the results of the analysis, the condition of the pre-reclaimed land of quartz sand is classified as infertile. Nutrient levels in the pre-reclaimed land were mostly low, and this is an important factor inhibiting plants from growing at the study site.

Chemical analyses of Urartian bronze objects from the Ayanis fortress

The bronze finds from the Ayanis Fortress, dated to Rusa (son of Argishti) (680–640 BC), were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to investigate the alloying techniques of Urartian bronze work. The feasibility of a handheld portable X-ray fluorescence (pXRF) method for measuring the elemental characteristics of ancient bronze artifacts was also examined. The chemical data revealed that Ayanis bronze objects were made of copper-tin (Cu-Sn) alloy, but the Cu/Sn ratio varied for the artifacts, showing that tailored alloying techniques were not applied with regard to the function of the objects. Following a comparison of the elemental data from bulk and surface analysis, pXRF was deemed less accurate because of corrosion layers on the surface, even for mechanically cleaned samples. Microstructural observation showed features that imply several cold working and annealing cycles were applied during manufacture.

A non-destructive X-ray fluorescence method of analysis of formalin fixed-paraffin embedded biopsied samples for biomarkers for breast and colon cancer

In this work we present a methodology for the non-destructive elemental determination of formalin-fixed paraffin-embedded (FFPE) human tissue samples based on the Fundamental Parameters method for the quantification of micro Energy Dispersive X Ray Fluorescence (micro-EDXRF) area scans.This methodology intended to overcome two major constraints in the analysis of paraffin embedded tissue samples – retrieval of optimal region of analysis of the tissue within the paraffin block and the determination of the dark matrix composition of the biopsied sample. This way, an image treatment algorithm, based on R® tool to select the regions of the micro-EDXRF area scans was developed. Also, different dark matrix compositions were evaluated using varying combinations of H, C, N and O until the most accurate matrix was found: 8% H, 15% C, 1% N and 60% O for breast FFPE samples and 8% H, 23% C, 2% N and 55% O for colon. The developed methodology was applied to paired normal-tumour samples of breast and colon biopsied tissues in order to gauge potential elemental biomarkers for carcinogenesis in these tissues. The obtained results showed distinctive biomarkers for breast and for colon: there was a significant increase of P, S, K and Fe in both tissues, while a significant increase of Ca an Zn concentrations was also determined for breast tumour samples.

Composition and formation conditions of nephrite, Nyrdvomenshor deposit, Polar Urals

Research subject. Nephrite and related rocks from the Nyrdvomenshor deposit in the Polar Urals were studied. The Nyrdvomenshor deposit is located in the exocontact of the Rai-Iz ultramafic massif, confined to the Main Ural Fault. The deposit was developed in the process of geological exploration; a license has been issued for a part of the deposit. Aim. To study the nephrite and related rocks from alluvial of the deposit, to formulate a model of its origin. Methods. Qualitative characteristics were assessed visually using a binocular microscope and a special flashlight. The chemical composition was determined by the X-ray fluorescence method. The contents of trace elements were determined by ICP-MS analysis. The mineral composition was studied on a scanning electron microscope with an energy dispersive microanalysis system. Measurements of the isotopic composition of oxygen were carried out. Results. In addition to vesuvianite rodingite, hydrogarnet rodingite was found to be common at the deposit. The studied nephrite is substandard. Tremolite predominates in nephrite, diopside forms relic grains. Uvarovite is widespread, forming both idiomorphic grains, sometimes sheath, less often elongated xenomorphic, and replacing chromite. Omphacite overgrows grains of chromite and uvarovite. Grains of the Fe-dominant mineral of the shuiskite group are noted. Conclusions. Nephrite was formed through both metamorphic and metasomatic processes. Serpentinite was replaced by diopside, which was then replaced by nephrite. Metamorphism enhanced the metasomatism of the serpentinite melange and provided the cryptocrystalline tangled fibrous structure of the nephrite. Then metamorphism and metasomatism led to the formation of omphacite and cracking of the nephrite, which reduced its quality. As these processes progressed, the contribution of the crustal fluid increased, which is confirmed by the results of studying the oxygen isotopic composition of nephrite and other rocks of the deposit.

STUDY OF WATER ABSORPTION OF GEOPOLYMER MATERIALS BASED ON IRON ORE ENRICHMENT TAILINGS

As you know, the problem of environmental safety is important in the process of mining and processing of ore and non-metallic minerals. In the process of primary processing of ore minerals, the so-called enrichment tailings or production wastes are formed. The resulting waste accumulates in huge quantities, contributing to changes in the landscape and worsening the hydrogeological and sanitary conditions of the environment. In addition, rainfall and meltwater contribute to the constant leaching of heavy metals from waste dumps, which eventually leads to the pollution of groundwater, rivers and lakes. Therefore, the important ecological task of rational disposal of mining tailings is very relevant around the world. Research aimed at developing and obtaining new materials on the basis of this waste is of the greatest interest. One of such directions is the utilization (immobilization) of mining tailings when obtaining of geopolymer materials, which eliminates the leaching of heavy metals from the volume of the obtained material. Over the past 60 years, millions of tons of enrichment tailings have accumulated at the Dashkesan iron ore deposit, which are waiting to be disposed of. For this reason, the tailings of Dashkesan iron ore enrichment were used as a mineral filler for producing geopolymer material. Mineralogical and chemical compositions of enrichment tailings were studied using X-ray phase and X-ray fluorescence methods. Water absorption of the obtained specimens of geopolymer material was researched in accordance with the known methodology. It was revealed that with the increase of mineral filler content from 60 to 90%wt. the value of water absorption of geopolymer material specimens in the first five minutes of exposure increased from 1 to 10,2%, respectively. With the increase of mineral filler content from 60 to 90%wt. the maximum value of water absorption increases from 2,6 to 10,2%, respectively. Keywords: geopolymer, water absorption, enrichment tailings, iron ore.

Resolution-enhanced X-ray fluorescence microscopy via deep residual networks

Multimodal hard X-ray scanning probe microscopy has been extensively used to study functional materials providing multiple contrast mechanisms. For instance, combining ptychography with X-ray fluorescence (XRF) microscopy reveals structural and chemical properties simultaneously. While ptychography can achieve diffraction-limited spatial resolution, the resolution of XRF is limited by the X-ray probe size. Here, we develop a machine learning (ML) model to overcome this problem by decoupling the impact of the X-ray probe from the XRF signal. The enhanced spatial resolution was observed for both simulated and experimental XRF data, showing superior performance over the state-of-the-art scanning XRF method with different nano-sized X-ray probes. Enhanced spatial resolutions were also observed for the accompanying XRF tomography reconstructions. Using this probe profile deconvolution with the proposed ML solution to enhance the spatial resolution of XRF microscopy will be broadly applicable across both functional materials and biological imaging with XRF and other related application areas.