Potential of Dual and Multi Energy XRT and CT Analyses on Iron Formations

Abstract

Dual and multi energy X-ray transmission imaging (DE-/ME-XRT) are powerful tools to acquire quantitative material characteristics of diverse samples without destruction. As those X-ray imaging techniques are based on the projection onto the imaging plane, only two-dimensional data can be obtained. To acquire three-dimensional information and a complete examination on topology and spatial trends of materials, computed tomography (CT) can be used. In combination, these methods may offer a robust non-destructive testing technique for research and industrial applications. For example, the iron ore mining and processing industry requires the ratio of economic iron minerals to siliceous waste material for resource and reserve estimations, and for efficient sorting prior to beneficiation, to avoid equipment destruction due to highly abrasive quartz. While XRT provides information concerning the thickness, areal density and mass fraction of iron and the respective background material, CT may deliver size, distribution and orientation of internal structures. Our study shows that the data provided by XRT and CT is reliable and, together with data processing, can be successfully applied for distinguishing iron oxide rich parts from waste. Furthermore, heavy element bearing minerals such as baryte, uraninite, galena and monazite can be detected.

Dual and Multi Energy XRT and CT Analyses Applied to Copper-Molybdenum Mineralizations in Porphyry Deposits

“…However, previous results on iron-oxide ores show the reliability of the used methods [6]. Furthermore, all methods show similar trends for the medium-Z fraction.…”

“…The 3D reconstructions of the five rock samples were processed to obtain characteristic information such as the size and number of internal fractions [6,14]. To reduce noise, a 5 × 5 × 5 median filter (ball mask) was applied to the 3D data.…”

“…The obtainable information is thus limited. Dual energy (DE) and multi energy (ME) XRT use the material and energy dependence of X-ray attenuation to gain additional knowledge on the chemical composition of the samples [6].…”

“…While measurement and reconstruction are more time consuming than XRT, the method allows us to investigate the internal sample structure by virtually slicing the sample in any arbitrary direction. In this way, the local variation of minerals can be visualized [6].…”

Mounted Single Particle Characterization for 3D Mineralogical Analysis—MSPaCMAn

“…The 3D microstructure of samples can be segmented into regions with similar grey-values (e.g., mineral or group of minerals) for analyses and quantification [12]. For example, volume, grain sizes, surface area, spatial distribution and associations of individual particles or phases can be quantified [14][15][16][17][18][19][20]. Despite the advantages of measuring 3D microstructures, classifying the phases composing those microstructures based on grey-values remains challenging due to imaging artefacts [21,22] that cause a broadening of the grey-scale interval that can be attributed to a phase [23,24].…”