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

For many decades, X-ray diffraction (XRD) has been used for material characterization. With the recent development in material science understanding and technology, various new materials are being developed, which requires upgrading the existing analytical techniques such that 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, all in one place. It further discusses the future research directions, especially the use of artificial intelligence and machine learning tools for improving the effectiveness and accuracy of XRD technique for mineral characterization. It has been focused that 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 for mineral characterization are compiled in this short yet comprehensive review that would benefit specialists and engineers in the chemical, mining, iron, metallurgy, and steel industries.

Mineral Preparation Using Rod Mill for Mineral Galena Characterization

Galena mineral preparation was carried out for mineral characterization. The mineral characterization carried out included XRD (X-Ray Diffraction), XRF (X-Ray Fluorescence), SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-Ray). The preparation of galena minerals begins with the process of reducing the grain size including crushing and grinding. The results of crushing and grinding are then separated based on grain size using a sieve or siever to get a grain size of -200 mesh. The grinding process using a rod mill needs to be timed, so that the results are not too fine which is causing the recovery in the mineral concentration process to be low.

Orange Pickeringite from the Algares 30-Level Adit, Aljustrel Mine, Iberian Pyrite Belt, Portugal

The sheltered environment of the Algares +30 level adit (underground mine gallery) contributes to the preservation of secondary water-soluble minerals formed on the tunnel walls. The massive sulphide and related stockwork zone are hosted by the Mine Tuff volcanic unit and are exposed in the walls of the gallery, showing intense oxidation and hydrothermal alteration. Minerals from the halotrichite group were identified on the efflorescent salts, typically white fine-acicular crystals but also on aggregates with dark orange/brownish colour. Mineral characterization was performed using several methods and analytical techniques (XRD, XRF-WDS, SEM-EDS, DTA-TG), and the chemical formulas were calculated maintaining the ratio A:B ≅ 1:2 in accordance with the general formula of the halotrichite group, AB2(SO4)4·22H2O. This methodology allowed the assignment of the orange colour to the presence of trivalent iron on iron-rich pickeringite in partial substitution of aluminium.

Review on Mineral Characterization of Precambrian Charnockites – using PIXE Technique

Particle Induced X-ray Emission (PIXE) has been applied to a analytical tool for long range of major, minor and trace elemental analysis in Precambrian charnockites. PIXE is sensitive and non-destructive method for some elemental analysis in a variety of Precambrian charnockite rocks down to levels of a few parts per million and it is not valid for all remaining elements in the composition. The elements identified in the Precambrian charnokite rock are Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb, Sr, Y, Zr, Nb, Mo, Ru, Ag, Pb are identified without exact values by PIXE but the elements minor F, major elements Na, Mg, Al, Si, P and Ba and traces of Co, Th and U not detected due to various reasons even though there present in the charnockites, because of PIXE which is operation at 3 MeV energy and characterization material of charnockite mineral investigated. In mineral characterization of charnockite rocks, elemental errors in concentration of the compositions explained by comparing with present and previous studies.