X-ray diffraction (XRD) is an important and widely used material characterization technique. With the recent development in material science technology and understanding, various new materials are being developed, which requires upgrading the existing analytical techniques such that emerging intricate problems can be solved. Although XRD is a well-established non-destructive technique, it still requires further improvements in its characterization capabilities, especially when dealing with complex mineral structures. The present review conducts comprehensive discussions on atomic crystal structure, XRD principle, its applications, uncertainty during XRD analysis, and required safety precautions. The future research directions, especially the use of artificial intelligence and machine learning tools, for improving the effectiveness and accuracy of the XRD technique, are discussed for mineral characterization. The topics covered include how XRD patterns can be utilized for a thorough understanding of the crystalline structure, size, and orientation, dislocation density, phase identification, quantification, and transformation, information about lattice parameters, residual stress, and strain, and thermal expansion coefficient of materials. All these important discussions on XRD analysis for mineral characterization are compiled in this comprehensive review, so that it can benefit specialists and engineers in the chemical, mining, iron, metallurgy, and steel industries. 

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X-ray Diffraction Techniques for Mineral Characterization: A Review for Engineers of the Fundamentals, Applications, and Research Directions

Coal fly ash is found to be one of the key pollutants worldwide due to its toxic heavy metal content. However, due to advancements in technology, coal fly ash has gained importance in various emerging fields. They are rich sources of carbonaceous particles which remain unburnt during burning of various coals in thermal power plants (TPPs). Various carbonaceous nanoparticles in the form of fullerenes, soot, and carbon nanotubes could be recovered from coal fly ash by applying trending techniques. Moreover, coal fly ash is comprised of rich sources of organic carbons such as polycyclic and polyaromatic hydrocarbons that are used in various industries for the development of carbon-derived value-added materials and nanocomposites. Here, we focus on all the types of carbon nanominerals from coal fly ash with the latest techniques applied. Moreover, we also emphasize the recovery of organic carbons in polyaromatic (PAHs) and polycyclic hydrocarbons (PCHs) from coal fly ash (CFA). Finally, we try to elucidate the latest applications of such carbon particle in the industry.

Recent Advances in Methods for the Recovery of Carbon Nanominerals and Polyaromatic Hydrocarbons from Coal Fly Ash and Their Emerging Applications

This investigation aimed at evaluating the efficiency of micro and nanoclays as a low-cost material for the removal of crystal violet (CV) dye from an aqueous solution. The impacts of various factors (contact time, pH, adsorbent dosage, temperature, initial dye concentration) on the adsorption process have been taken into consideration. Six micro and nanoclay samples were obtained by treating clay materials collected from different locations in the Albaha region, Saudi Arabia. Out of the six tested micro and nanoclays materials, two (NCQ1 and NCQ3) were selected based on the highest adsorption efficiency for complete experimentation. The morphology and structure of the selected micro and nanoclay adsorbents were characterized by various techniques: SEM-EDX, FTIR, XRF, XRD, and ICP-MS. The XRF showed that the main oxides of both nanoclays were SiO2, Al2O3, Fe2O3, K2O, CaO, and MgO, and the rest were impurities. All the parameters affecting the adsorption of CV dye were optimized in a batch system, and the optimized working conditions were an equilibrium time of 120 min, a dose of 30 mg, a temperature of 25 °C, and an initial CV concentration of 400 mg/L. The equilibrium data were tested using nonlinear isotherm and kinetic models, which showed that the Freundlich isotherm and pseudo-second-order kinetics gave the best fit with the experimental data, indicating a physico-chemical interaction occurred between the CV dye and both selected micro and nanoclay surfaces. The maximum adsorption capacities of NCQ1 and NCQ3 adsorbents were 206.73 and 203.66 mg/g, respectively, at 25 °C. The thermodynamic factors revealed that the CV dye adsorption of both micro and nanoclays was spontaneous and showed an exothermic process. Therefore, the examined natural micro and nanoclays adsorbents are promising effective adsorbents for the elimination of CV dye from an aqueous environment.

Natural Clay as a Low-Cost Adsorbent for Crystal Violet Dye Removal and Antimicrobial Activity.

Comprehensive utilization of foundry dust: Coal powder and clay minerals separation by ultrasonic-assisted flotation.

A biodegradable in situ Zn-Mg2Ge composite for bone-implant applications.

Comparative study on performance and microstructure of composite water-soluble salt core material for manufacturing hollow zinc alloy castings

The invention belongs to the technical field of casting, and particularly relates to a high-strength composite salt core material for low-melting-point alloy casting. The high-strength composite salt core material comprises, by mass, 70%-100% of water-soluble inorganic salt and 0%-30% of a reinforcement, wherein the water-soluble inorganic salt comprises one of low-melting-point salts including potassium nitrate and sodium nitrate, and at least one of high-melting-point salts including potassium chloride, sodium chloride, potassium bromide and sodium bromide, and positive ions of the low-melting-point slats are the same as positive ions of the high-melting-point salts. The invention further discloses a preparation method of a high-strength composite salt core, and an obtained salt core product. The prepared composite salt core has extremely high bending strength, excellent hygroscopicity and small volume shrinkage, and the comprehensive performance is excellent. In addition, the preparation technique of the high-strength composite salt core is simple, raw materials are cheap, and industrial production is easy.

High-strength composite salt core material for low-melting-point alloy casting, salt core and preparation method

The water-soluble salt core with higher bending strength and toughness is necessary to withstand the high pressure needed to manufacture some complex parts by high pressure die casting (HPDC). In this paper, the effects of glass fiber size and content on microstructures and properties of KNO3-based (KNO3-30 mol%KCl) water-soluble salt core were systematically studied. The results showed that increasing the glass fiber content greatly improved the bending strength and impact toughness of the KNO3-based salt core, decreased the water solubility rate and increased the humidity resistance. In addition, increasing the glass fiber size sharply enhanced the impact toughness of the KNO3-based salt core, while decreasing the bending strength, water solubility rate and humidity resistance. The maximum bending strength and impact toughness of the reinforced KNO3-based salt core with the glass fiber were, respectively, 41.32 ± 0.38 MPa and 2.146 ± 0.108 kJ/m2, which were 55.9% and 315.1% higher than those of the unreinforced KNO3-based salt core, respectively. The microstructures show that the glass fibers were evenly distributed in the KNO3-based salt core, which significantly refined the KCl primary phases, especially for the 12.5-μm glass fiber. Meanwhile, many fiber pull-out holes were observed in the KNO3-based salt cores with 75-μm and 25-μm glass fiber. The grain refinement, fiber pull-out and crack deflection were the main mechanism for improving the strength and toughness of the KNO3-based salt core.

Effects of glass fiber size and content on microstructures and properties of KNO3-based water-soluble salt core for high pressure die casting

The invention belongs to the technical field of recycle of old water glass sand, and discloses an ultrasonic wet method for recycling the old water glass sand The ultrasonic wet method comprises the following steps: adding initial old water glass sand into water or an alkaline solution, mixing the two, performing ultrasonic treatment for 1-30 minutes to obtain a sand and water mixture, dewatering the sand and water mixture till the water content is not higher than 4% to obtain initial recycled sand and a waste alkali solution, adding the initial recycled sand into water, and repeating processes of mixing, ultrasonic treatment and dewatering till the sodium oxide content of the recycled sand is not higher that 005% so as to achieve the recycle of the old water glass sand By the ultrasonic wet method, the obtained recycled sand is high in release rate (higher than 95%) and good in performance; in addition, the water consumption is low, so that the sewage amount can be reduced and the sewage treatment cost is reduced

Gong Xiaolong

Papers

Comprehensive utilization of foundry dust: Coal powder and clay minerals separation by ultrasonic-assisted flotation.

Comparative study on performance and microstructure of composite water-soluble salt core material for manufacturing hollow zinc alloy castings

High-strength composite salt core material for low-melting-point alloy casting, salt core and preparation method

Effects of glass fiber size and content on microstructures and properties of KNO3-based water-soluble salt core for high pressure die casting

Ultrasonic wet method for recycling old water glass sand