Quantitative X-ray Research Articles

Influence of pretreatments on accelerated dry carbonation of MSWI fly ash under medium temperatures

The dry gas-solid carbonation of municipal solid waste incineration fly ash was investigated in order to attain harmless treatments. The main composition of fly ash was Ca-containing compounds, which could react with CO2 to produce carbonate for solidification, alleviating the pollution of heavy metals and soluble chlorides originated from fly ash. The accelerated carbonation tests were conducted under medium temperatures (350 °C–550 °C) in the fixed-bed experimental system. Moreover, the effects of pretreatment involving calcination and water-washing on carbonation were studied. The composition, phase content and structure of fly ash were determined using quantitative X-ray diffraction (QXRD) and scanning electron microscope (SEM). Additionally, the leaching characteristics of Cu, Zn, Pb, Cr, Cd, and Ni were investigated. The results revealed that pretreatments influenced mass gain during carbonation. The mass gain of calcined fly ash increased with the increasing temperature, whereas the mass gain of raw fly ash and washed fly ash decreased after 400 °C. The QXRD calculation indicated that CaClOH did not decompose completely at 600 °C. The CaCO3 content of carbonated washed fly ash reached the maximum of 88% at 550 °C. In addition, raw fly ash and washed fly ash could be carbonated completely at 350 °C, whereas calcined fly ash required 400 °C. The leaching characteristics analysis showed that pretreatments would increase the leaching concentration of heavy metals (except Pb). However, the leaching concentration of Cu, Pb and Cr decreased obviously after carbonation. For fly ash in this study, carbonation at 400 °C–450 °C can meet the requirements. The study provides useful information for the research and applications of dry carbonation of MSWI fly ash.

Effects of duration of solution heat treatment on the evolution of 3D microstructure in AlSi7Cu3 alloy: A quantitative X-ray tomography study

The evolution of the microstructure of an AlSi7Cu3 alloy is investigated by optical microscopy and X-ray tomography in as-cast condition and with subsequent solution treatments for 2 h 30 min and 50 h at 495 °C, respectively. The analyzed microstructure contains pores and hard inclusions, i.e. eutectic Si, iron-intermetallics, and Al2Cu phases. 2D microscopic surface examination was performed to reveal the characteristics of eutectic Si phase while 3D characterization by X-ray tomography (Lab-CT) was performed for the pores, iron-intermetallics, and Al2Cu phases. The 3D quantitative characterization can provide new insight into the microstructures amount, size and morphology change mechanisms during heat treatment. The Al2Cu phase, which presents a 3D interconnected structure in the as-cast condition, undergoes significant morphological changes during the solution heat treatment. The incipient melting of Al2Cu phase was evidenced after 50 h of solution treatment at 495 °C, which leads to the formation of small pores (<60 μm). Statistical analyses of the Al2Cu particle distribution, their size and their local mean curvatures describe the disintegration of the interconnected network structure followed by the dissolving of the disconnected particles. The eutectic Si undergoes fragmentation, spheroidization, and coarsening during the solution treatment.

Preparation of sample solutions using nanoimprint films for quantitative X-ray fluorescence analysis by thin film fundamental parameter method

Various sample preparation methods have been proposed for X-ray fluorescence analysis of mineral components in a liquid. Among them, the dry spot method is widely used; however, the issue is that the prepared dried residue is non-uniform. We developed nanoimprint films using the thermal nanoimprint method. A uniform and thin dry residue was prepared using the nanoimprint film. The thin film fundamental parameter method, a quantitative analysis method used in X-ray fluorescence analysis, was applied to dried residues to analyze their content. As a result, the analysis value was found to be close to the authentication and inductively coupled plasma atomic emission spectromy analysis values.

Phase evolutions of cementitious materials with very low water/binder ratios

High-performance and ultra-high-performance concrete have been increasingly used as building materials in modern construction, and their superior properties derived from a tailored microstructure. In this study, Rietveld quantitative X-ray diffraction analysis was adopted to investigate phase evolutions of four cementitious pastes with varied addition of fly ash or silica fume at very low water/binder ratios. The results indicate that the phase changes concerning the contents of the major clinker phases mainly happen within the first 7 d. The content of portlandite (CH) in pure cement paste increases monotonically while, due to pozzolanic reaction, it decreases in blended pastes between 7 and 28 d. At early age, the addition of silica fume accelerates the hydration of cement, while the introduction of fly ash shows significant retardation especially at 1 d. The degree of hydration (DOH) of cement is mainly determined by the effective water/cement ratio of the paste, and the incorporation of fly ash, while initially producing little reaction, results in a higher DOH of cement. With steam curing, the content of CH significantly decreases in the blended pastes, which indicates a promoted pozzolanic reaction.

Polysulfide driven degradation in lithium–sulfur batteries during cycling – quantitative and high time-resolution operando X-ray absorption study for dissolved polysulfides probed at both electrode sides

The quantitative evolution of dissolved polysulfides at both electrode sides of lithium–sulfur batteries is determined with operando X-ray spectrometry.

X-ray spectral analysis development in Novosibirsk city (Electron probe microanalysis and X-ray fluorescence analysis using the synchrotron radiation)

Current article considers the contribution of X-ray physicists from the city of Novosibirsk to the formation and development of the two X-ray spectral analysis directions: electron probe microanalysis and X-ray fluorescence analysis using the synchrotron radiation. The research on geological topics at the Institute of Geology and Geophysics of the Siberian Branch of the USSR Academy of Sciences using the MS-46 electron probe microanalyzer of the French company CAMECA (since 1967) served as the basis for the development of methods for the quantitative X-ray microanalysis of rock-forming minerals as the methods for quantitative determination of the contents of elements with low atomic numbers in the long-wavelength X-ray region were still in their infancy. With the development and the improvement of the method’s technical base (microprobes JXA-5A, JEOL, 1975; Kamebaks Micro, CAMECA, 1981; JXA-8100, JEOL, 2003; JXA-8230, JEOL, 2016; electronic computing), the software for controlling the operation of devices and converting the measured intensities of the analytical lines into the concentration of elements continued to changed and improve. The first results of elemental analysis, obtained using the synchrotron radiation to excite X-ray fluorescence at the VEPP-3 accelerating ring at the Institute of Nuclear Physics of the Siberian Branch of the USSR Academy of Sciences, were published in1977. Inthe following years, at the station of elemental SRXRF, samples of various nature were studied — biological (bio tissues of the heart, liver, lungs, hairs, bones, plants), geological, environmental objects (soils, sediments, aerosols, etc.), archaeological sites as well as new technological materials. The procedures for the determination of chemical elements in low-mass samples (milligrams) in unique samples of lunar soil samples, biopsy material of human myocardial tissues, etc. have been developed. The scanning device at the elemental SRXRF station made it possible to obtain the information for reconstructing the climate change for different periods of time – from 100 to 1000 years. A new non-destructive method of confocal X-ray microscopy for studying micro-objects and visualizing the distribution of chemical elements in extended objects on this station are currently being developed.

MINERALOGICAL ANALYSIS OF SAMPLES FROM THE OLD BOR MINE FLOTATION TAILING, REPUBLIC SERBIA

The mineralogical analysis of the samples from the Bor’s mine tailings, which were taken from boreholes, was realized in two stages. As a qualitative ore microscopic and quantitative X-ray structural analysis. About a dozen ore minerals, of higher intensity, were detected by ore microscopic analysis, such as chalcopyrite, magnetite, pyrite, bornite, molybdenite, native gold, etc. Quantitatively, with the help of the scanning-electron microscope, the compositions of all significant ore minerals were determined, from which it should be emphasized that in most of them there are no major deviations from the reference values. For chalcopyrite as the most intense mineral, the copper concentration ranged from 33.24 to 36.33% Cu, iron from 29.78 to 32.13% Fe and sulfur from 32.40 to 35.73% S, while in bornite those concentrations ranged from 61.99 to 64.01% Cu, from 11.40 to 13.01% Fe and from 23.69 to 25.43% S. The quantification of XRD confirmed the presence of pyrite, quartz, nacrite, alunite, anorthite, hornblende and others.

Petrography and Geochemical Characteristics of Nari Sandstone in Lower Indus Basin, Sindh, Pakistan

Pakistan has been suffering from severe energy crisis for decades. Discovering new oil and gas fields plays significant role in alleviating the energy deficit. Exploitation and development of new fields for the country is very challenging due to economic, technological, social and environmental concerns. Hence, it is essential to assess the potential of hydrocarbon bearing formations using integrated analysis techniques in order to explore the resources efficiently. In this paper, we have analyzed Nari sandstone reservoir potential of the country. The key objectives of the study are to characterize petrographic, mineralogical and microstructural data through laboratory study on Oligocene strata of Nari sandstone in the lower Indus Basin. For this purpose, we collected several exposed outcrop samples from different stations in the onshore areas of Nari Sandstone formation. The work performed includes, the integrated study of petrography using Scanning Electron Microscopy (SEM) along with Energy Dispersive Spectrometry (EDS) application. In addition, Quantitative X-Ray Diffraction (QXRD) analysis was performed. The results revealed that these sandstones were mainly composed of quartz grains, which are surrounded by calcite cement. EDS elemental sequence shows Calcium (Ca), Carbon (C),Silicon (Si), Iron (Fe), Magnesium (Mg), Aluminum (AI) and K (Potassium) in variable intensities in the samples indicating the presence of different minerals within these rocks such as quartz, calcite, clay and ferruginous cement. This study is the comprehensive collection of data of Nari sandstones that is essential to assess the potential of hydrocarbon bearing formations.

Physical and Chemical Fundamentals of Sodium Phosphate Use in Foundry Production

The technology of synthesis of inorganic binder material based on sodium tripolyphosphate Na5P3O10 and orthophosphoric acid has been developed. The sequence of physicochemical transformations in this system, as well as the optimal mass ratio of orthophosphoric acid and sodium tripolyphosphate are established. The research uses methods of quantitative and qualitative X-ray phase analysis, differential thermal analysis, standard methods of testing samples for compressive strength. The ratios of the atomic radii of the cation (Na) and the anion (P2O7), as well as the presence of hydrogen bonds, provide a significant increase in the binding potential compared to other sodium phosphates. It was found that the strengthening of mixtures with 2…8 mass parts including sodium pyrophosphate, the filler of which is quartz-based sand, occurs as intensely as possible when heated to 150°C. A further increase in temperature above 250 °C leads to the conversion of sodium pyrophosphate to ordinary (non-polymeric) metaphosphate NaPO3, which exists without changes in chemical structure up to 1000°C. The developed binder material, given the global trends of decarbonization and resource conservation, is a competitive alternative to widely used synthetic resins and other organic materials. It does not contain harmful substances and does not emit dangerous products when heated.

Arsenic Adsorption by Some Iron Oxide Minerals: Influence of Interfacial Chemistry

The dramatic increase in hydrometallurgical extraction of gold from arsenic bearing gold ores has inevitably resulted in the release of arsenic into the environment worldwide. Residual arsenic minerals in tailings storage facilities can be oxidised and mobilise arsenic into the environment. This can contaminate soils, ground and surface waters and eventually biota. In spite of well-established technologies and recent advances in arsenic remediation, there are limited knowledge and understanding of the iron oxide substrate (goethite, hematite and magnetite) mineralogy and the fate of arsenic on the surface charge of these iron oxide substrates in an aqueous media during adsorption. The aim of the present study was to investigate the influence of interfacial chemistry on arsenic adsorption onto selected iron oxide particles to assist in developing a better understanding and new knowledge in arsenic removal from contaminated waters. Bulk mineralogy and partial chemical composition of selected iron oxide minerals were obtained using quantitative x-ray diffractometry (QXRD) and acid digestion followed by metal determination using inductively coupled plasma optical emission spectrometry (ICP-OES) respectively. Zeta Potential measurements involving iron oxide particles as arsenic adsorbents were carried out to elucidate the influence of interfacial chemistry on the adsorption behavior of arsenic from solution. The study confirmed that the iron oxide minerals were predominantly hematite, magnetite and goethite with goethite containing significant amounts of quartz. Arsenic adsorption was pH dependent and strongly influenced the zeta potential and isoelectric point (IEP) of the iron oxide particles. The zeta potential of all substrates studied was strongly positive at pH 2 but indicated a reversal at pH ~ &gt; 9. The interaction between substrates, arsenic and its hydrolysable products resulted in significant decrease in the magnitude of zeta potential and change in IEP indicating specific adsorption.&#x0D; &#x0D; Keywords: Arsenic, Adsorption, Iron Oxide Minerals, Zeta Potential

Influences of formation potential on oxide film of TC4 in 0.5 M sulfuric acid

The correlation between film formation potential and the thickness, valence state, and corrosion resistance of the oxide film on TC4 (Ti-6Al-4V) in 0.5 M sulfuric acid is investigated. Potentiostatic polarization and electrochemical impedance spectra measurements reveal the passivation process and electrochemical properties of TC4 alloy. Relative quantitative X-ray photoelectron spectroscopy and Auger electron spectrum analyses illustrate that the formation of thicker and higher valence state film is promoted by the increase in applied potential. Those passive films formed at the potentials in passive region show good protections, and the corrosion resistance of the passive film becomes larger with the increase in passivation potentials. The TiO2 form in oxide films generated under the above conditions transforms from anatase to rutile with the increase in applied potentials and this transformation is found through comparing with the X-ray absorption spectroscopy of reference oxides.

Phase-Vortex Removal for Quantitative X-Ray Nanotomography with Near-Field Ptychography

X-ray ptychotomography in the near-field regime is a promising technique for high-resolution, quantitative, and nondestructive investigations in materials science, paleontology, and biomedicine. X-ray near-field ptychography has been previously demonstrated in projection and tomography mode, but the quantitativeness of the reconstructed data has never been discussed in detail. Here, we use measurements of a sample made of aluminum and nickel microparticles to evaluate the quantitativeness of the volumetric mass-density data. Moreover, we propose an algorithm (VortRem) for the removal of phase vortexes, a type of artifact that frequently occurs in holographic methods. VortRem and the results presented here may be fundamental for extending the applicability of this emerging technique to quantitative three-dimensional characterization studies of light as well as dense samples down to the nanoscale.

Co-precipitation of Cu and Zn in precipitation of struvite

Struvite recovered from wastewater can be used as a slow-release fertilizer. Nevertheless, hazardous metals easily precipitated with struvite would increase the ecological risk for its agricultural use. In this study, the influence of individual and coexistence of Cu and Zn on the precipitation of struvite was investigated. The loading of Cu and/or Zn in precipitates increased with the increase of initial metal concentrations (0.1–100 mg/L). Quantitative X-ray diffraction (QXRD) analysis revealed that the increase of Cu and/or Zn level in reaction solution disturbed crystal growth of struvite and promoted the formation of amorphous phase(s). Scanning electron microscopy (SEM) revealed the pit formation on struvite crystal surfaces, combined with X-ray photoelectron spectroscopy (XPS) data, the results indicated a surface interaction for the formation of Cu-OH and Cu-NH3 on struvite surface at Cu of 0.1–10 mg/L. With the increase of Cu to 25–100 mg/L, the precipitation of amorphous Cu phosphate(s) was confirmed by XPS and QXRD. At Zn of 0.1–10 mg/L, the enrichment of Zn-PO4 and Zn-OH on struvite surface was observed, whereas, the precipitation of amorphous Zn hydroxide(s) was confirmed at Zn of 25–100 mg/L. At Cu and Zn co-existed solution, the decrease of Cu-PO4 and increase of Zn-PO4 suggested the competitive binding of PO4 between Cu and Zn. In addition, the formation of amorphous Mg hydroxide(s) and phosphate(s) was detected regardless of the addition of Cu in solutions. The overall results revealed that the existence of Cu and Zn during struvite formation can greatly affect its content by formation of different metal-containing products.

Production of autoclaved aerated concrete with silica raw materials of a higher solubility than quartz part I: Influence of calcined diatomaceous earth

This study examines the effects of calcined diatomaceous earth (C-DE) as a silica raw material of a higher solubility than quartz, on the mechanical and microstructural properties of autoclaved aerated concrete (AAC) produced at the steam curing temperature of 192 °C for 6 h. Quartz within an AAC mixture was replaced at various replacement ratios by C-DE. The resultant phases were characterized using quantitative and qualitative X-ray diffraction (XRD), scanning electron microscopy (SEM), differential thermal analysis (DTA), and thermogravimetric analysis (TGA). In the mixtures with more than 50% substitution of quartz with C-DE, the autoclaving temperature of 192 °C with a duration of 6 h prevented the crystallization of amorphous calcium silicate hydrate (C-S-H) to tobermorite. The optimum strength was obtained at the substitution ratio of 75% despite having the lowest tobermorite content. By substituting quartz with C-DE for higher than 50%, plate-like tobermorite was changed to grass-like and amorphous C-S-H with low CaO/SiO2.

Improving diagnostics of periodontal diseases in children with connective tissue dysplasia based on X-ray morphometric and densitometric data

Relevance. Detection of maxillofacial pathomorphological changes in children with connective tissue dysplasia (CTD) allows identifying the nature and severity of disorders, as well as it serves the basis for selecting the best treatment options in view of the pathogenetic features. The purpose is to improve the diagnosis of periodontal diseases in children with CTD based on x-ray morphometric indices of the lower jaw and peripheral skeleton ultrasound osteodensitometry.Materials and methods. 92 children with varying CTD severity, and 43 healthy children, underwent cone-beam computed tomogram examination with a further analysis of their X-ray morphometric (quantitative, qualitative) values and the lower jaw optical density indices. Besides, the status of the peripheral skeleton bone tissue was also determined through quantitative ultrasonic densitometry.Results. Quantitative X-ray morphometric indices in healthy children and children with CTD revealed strong positive correlation with the Z-criterion of osteodensitometry, offering an objective reflection of the bone tissue status in the peripheral skeleton.Conclusion. CTD progression in children correlates with the bone structure destruction intensity in the maxillofacial area, an increase in chronic productive inflammation, a decrease in the bone density, bone tissue fibrous transformation, a decrease in the thickness of cortical, and fiber-dissociation in closing, plates, of the lower jaw, prevalence of mid- and fine-meshed bone pattern, disturbed spatial orientation and thinning of bone trabeculae, as well as the development of pathologies in the periodontium.

Remarkable bactericidal traits of a metal-ceramic composite coating elated by hierarchically structured surface.

SummaryA ceramic-based coating with a hierarchical surface structure was synthesized via solid-state reaction enabled by a double cathode glow discharge technique. This innovative coating comprises two distinct layers, specifically an outer layer with a well-aligned micro-pillar array and a dense inner layer. Both are composed of a face-centered cubic Cu(Co,Ni,Fe) solid solution phase together with a spinel-type Fe(Al,Cr)2O4 oxide. This coating exhibits superhydrophobicity and, yet, a very strong adhesion to water, i.e., the so-called “rose petal effect”. This coating also exhibits highly efficient antibacterial ability against both Staphylococcus aureus and Escherichia coli bacteria under both dark and visible light conditions. The excellent antibacterial property originates from the synergistic effects through the release of Cu ions coupled with photothermal activity upon light activation.

Premature failure of superheater tubes in a fertilizer plant

This work presents an unique premature failure of steam superheater tubes in a fertilizer plant. The heat exchanger tube bundle made of SA 213 grade T11 steel suffered from wall thinning in the vicinity of baffles causing reduction in wall thickness of the tubes leading to perforation and leakage of steam from the tube-side into the shell-side during service. The work presents details of metallurgical failure analysis involving: site inspection, visual inspection, chemical analysis, X-Ray diffraction, microstructural analysis, and computational fluid dynamics analysis. The qualitative and quantitative chemical analyses and X-Ray diffraction carried out on superheater residue followed by microstructural analysis of failed tubes confirmed that the tubes suffered from aggressive corrosion attack at certain locations due to hot flue gas carrying alkaline salts and refractory fines. To understand the mechanism of thinning and the reasons for the tube bundle failure only at certain locations, a detailed CFD analysis was carried out on model of the heat exchanger which simulated the flow pattern of the hot gas. The analysis comprehensively demonstrates that the hot gas carrying both corrosive and erosive species caused erosion-corrosion of the tubes in the vicinity of tube-baffle junction that lead to wall thinning and subsequent failure of the tube bundle. Suitable remedial measures are suggested to minimize such failures in future.

Study of Eco-Friendly Belite-Calcium Sulfoaluminate Cements Obtained from Special Wastes

Belite-calcium sulfoaluminate (BCSA) cements are special binders obtained from non-Portland clinkers; they have become increasingly more important due to their environmental impact during the manufacturing process compared to Portland cements, such as lower energy consumption and CO2 emissions. The aim of this paper was to assess the possible use of titanogypsum (T) and water potabilization sludge (W) to reduce the amount of natural raw materials (natural gypsum and clay, respectively) used in the production of BCSA cements. Three BCSA clinker generating raw mixes, containing T and/or W, and a reference mix based only on natural materials (limestone, clay, bauxite and natural gypsum) were heated in an electric furnace at temperatures ranging from 1200 to 1350 °C. Quantitative X-ray diffraction (XRD) analysis of the burnt products showed high conversion of reactants towards the main hydraulically active BCSA clinkers components (C2S and C4A3$), particularly at temperatures of 1300 and 1350 °C. Isothermal calorimetric measurements, differential thermal–thermogravimetric and XRD analyses as well as porosimetric measurements showed that all BCSA cements, from mixing the clinkers (at optimum temperatures) with commercial anhydrite, exhibited similar hydration behavior.

X-Ray Fluorescence Determination of Ore Elements in Ferromanganese Formations

Elemental analysis of ferromanganese formations (first of all, the determination of ore elements) is a necessary stage in the development of ore deposits. A technique for X-ray fluorescence quantitative analysis was proposed for the determination of iron, manganese, cobalt, nickel, copper, and zinc in oceanic ferromanganese formations (nodules and crusts). The studies were performed using a S4 Pioneer wavelength-dispersive spectrometer equipped with a LiF (200) crystal and a scintillation detector. In order to plot the calibration curves, sets of certified reference materials such as ferromanganese nodules, cobalt-bearing ferromanganese crusts, and pelagic sediments previously dried at 105°C for 24 h to remove hygroscopic moisture were used. Two sample preparation techniques were compared: pressing of powder samples with the use a boric acid substrate and homogenizing via fusion with lithium tetraborate at a ratio of 1 : 30 in an electric furnace at 1050°C. For each sample preparation technique, spectral overlaps and matrix correction methods (theoretical and empirical) were considered, and optimal calibration curves for determining ore elements were chosen. The accuracy of the X-ray fluorescence technique was assessed via analyzing a reference material FeMn-1 with a certified content of ore elements and a reference ferromanganese nodule sample preliminarily analyzed using a PerkinElmer M403 atomic absorption spectrometer. Both homogenization via fusion and analysis of pressed samples provide quantitative X-ray fluorescence determination of the main ore elements and can be used to assess the industrial significance of oceanic ferromanganese formations.

Single-frame far-field diffractive imaging with randomized illumination.

We introduce a single-frame diffractive imaging method called randomized probe imaging (RPI). In RPI, a sample is illuminated by a structured probe field containing speckles smaller than the sample's typical feature size. Quantitative amplitude and phase images are then reconstructed from the resulting far-field diffraction pattern. The experimental geometry of RPI is straightforward to implement, requires no near-field optics, and is applicable to extended samples. When the resulting data are analyzed with a complimentary algorithm, reliable reconstructions which are robust to missing data are achieved. To realize these benefits, a resolution limit associated with the numerical aperture of the probe-forming optics is imposed. RPI therefore offers an attractive modality for quantitative X-ray phase imaging when temporal resolution and reliability are critical but spatial resolution in the tens of nanometers is sufficient. We discuss the method, introduce a reconstruction algorithm, and present two proof-of-concept experiments: one using visible light, and one using soft X-rays.