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.
Residual barite deposits of the Southeast Missouri barite district were derived from the weathering of lower Paleozoic dolostones, chiefly the Upper Cambrian Potosi and Eminence Dolomites. Open-space, Mississippi Valley-type mineralization in the bedrock was controlled by the intersection of permeable lithologies with late Paleozoic near-vertical faults or linear zones of intense jointing. Linear trends of residual deposits are the surface expression of these bed-rock controls. A consistent mineralogical and barite textural zonation is disposed about the central structures. Sulfide mineralization is concentrated about the central structures, whereas barite is more widespread. Barite textures vary systematically from coarse bladed near the central structures to fine plumose more distally. Such zoning indicates outward ore fluid flow from the central faults and joint zones. Fluid inclusions in sphalerite indicate that warm Na-Ca-C1 brines (69ø-105øC, 20-25.5 equiv wt % NaC1) were present during early mineralization. Salinity data for fluid inclusions in barite (0-14 equiv wt % NaC1) may be representative of the barite mineralizing fluid, but contamination by later fluids is possible. Sulfur isotope studies show that the paragenetically early sulfides are isotopically lighter than later barite. Individual minerals involved in mainstage mineralization have the following ranges of •534S values: pyrite-marcasite, 8.4 to 34.7 per mil; galena, 3.2 to 11.8 per mil; sphalerite, 7.2 to 15.8 per mil; barite, 20.5 to 32.2 per mil. Barite ($34S values show enrichment in 34S away from the central fault. This spatial distribution is due to the incorporation of sulfate from two reservoirs. Isotopically light sulfate, developed most strongly about the central fault, originated from the oxidation of H2S in the ore fluid emanating from the central fault. The heavy sulfate that prevailed distally was indigenous to the host dolostone formation water. The/J•sO values of main-stage barite vary from 17.0 to 19.6 per mil and the range is attributed to mixing of two fluids of different oxygen isotope composition and to variable isotopic fractionation between sulfate and water due to changing temperature. The light sulfur and oxygen isotope composition of supergene barite (•j34S = 15.8%0,/j•80 = 9.0%0) is due to incorporation ofisotopically light sulfate produced locally during the oxidation of sulfide minerals in the soil environment. Barite precipitation was caused by fluid mixing, in which a Ba-Pb-Zn-H2S-bearing brine discharged from faults and joints into lower Paleozoic dolostones and mixed with an oxidizing, sulfate-bearing, dilute fluid. Increased supersaturation of barite with progressive mixing caused the systematic spatial variation of barite textures from coarse bladed near the central structures to fine plumose more distally. Similar barite-sulfide mineralization in the Central Missouri barite district probably formed in the same manner. Barite mineralization across the north flank of the Ozark dome postdates local Appalachian-O...
Firefighters, paramedics, nursing staff, and other occupational groups are in constant need of fast and proper cleaning of their professional workwear, not only during a pandemic. Thus, laundry technology needs to become more efficient and automated. Unfortunately, some steps of the cleaning process, such as finding and removing foreign items from pockets or belts, are still completed manually. This is not just time-consuming but potentially dangerous for the workers due to the hazardous nature of items such as scissors, scalpels, or syringes. Additionally, some items may damage the garments by staining or harm the laundry machines, causing malfunctions and process failure. On the one hand, these foreign items are often hidden inside the clothes, making detection very challenging with conventional superficial sensors. On the other hand, these items can be diverse and cannot be detected by metal detectors alone. X-ray transmission has proven to be a powerful tool for detecting items inside of objects. The dual-energy approach (DE-XRT) even allows obtaining quantitative information about the chemical composition of the measured materials. In this study, working garments were accompanied and filled with realistic foreign items. The potential of DE-XRT to detect those items was successfully shown.
X-ray transmission (XRT) and computed tomography (CT) was used on five samples from the Niaz porphyry Cu–Mo deposit in Iran, representing different alteration zones. Analysis of three-dimensional CT data revealed structural information and groups of elements with low, medium and high attenuation, which were assigned to minerals previously determined by scanning electron microscopy. Thus, the mineralization can be located, and the metal/waste ratio can be estimated, leading to more precise ore body modelling and process parameter determination. CT is useful for selected samples as it is time consuming. XRT can be used as real-time process on conveyor belts.
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