scholarly journals Quantitative X-ray µCT Measurement of the Effect of Ore Characteristics on Non-Surface Mineral Grain Leaching

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 746
Author(s):  
Mahdi Ghadiri ◽  
Susan T.L. Harrison ◽  
Marijke A. Fagan-Endres
Keyword(s):  
Particle Surface ◽  
Crack Development ◽  
Mineral Dissolution ◽  
Copper Recovery ◽  
Sulphide Mineral ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Penetration Distance ◽  
Maximum Penetration ◽  
Increasing Temperature

In heap (bio)leaching processes, a substantial fraction of the valuable mineral is positioned below the ore particle surface. X-ray micro-computed tomography (μCT) was used to quantify the effect of ore type and structure and operating temperature on the leaching of this mineral, to investigate the rate-controlling factors. Mini-leaching columns containing agglomerated chalcopyrite, pyrite, and malachite ores were scanned by X-ray μCT (13.40 µm resolution) at select time intervals. The leaching of a relatively porous malachite ore was reaction-controlled, with no leaching penetration limitation into the ore particles. For two less porous ore types, the structure and higher porosity of the agglomerate rim and conditions that resulted in the degradation of the full ore matrix structure were found to be the determining variables of the leaching extent and time. In the case of a chalcopyrite ore, an enhancement of copper recovery and sulphide mineral dissolution with increasing temperature was attributable to the increased leaching penetration distance and crack development in addition to thermodynamically expected increased leaching rate. Increasing temperature did not affect the maximum penetration distance for the waste rock containing pyrite, with no crack development observed. Overall increases in iron recovery were due to accelerated leaching rates, though diffusion or mineral access limitations were evident at a higher temperature.

Morphology and Affinities of Ampelocissites Seeds (Vitaceae: Ampelopsis clade) from the Paleogene of Texas, USA

2020 ◽  
Vol 45 (3) ◽  
pp. 478-482
Author(s):  
Steven R. Manchester
Keyword(s):  
Computed Tomography ◽  
Cross Sections ◽  
Seed Coat ◽  
Ct Scanning ◽  
Seed Morphology ◽  
Early Eocene ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Fossil Seeds ◽  
Fossil Genus

Abstract—The type material on which the fossil genus name Ampelocissites was established in 1929 has been reexamined with the aid of X-ray micro-computed tomography (μ-CT) scanning and compared with seeds of extant taxa to assess the relationships of these fossils within the grape family, Vitaceae. The specimens were collected from a sandstone of late Paleocene or early Eocene age. Although originally inferred by Berry to be intermediate in morphology between Ampelocissus and Vitis, the newly revealed details of seed morphology indicate that these seeds represent instead the Ampelopsis clade. Digital cross sections show that the seed coat maintains its thickness over the external surfaces, but diminishes quickly in the ventral infolds. This feature, along with the elliptical chalaza and lack of an apical groove, indicate that Ampelocissites lytlensis Berry probably represents Ampelopsis or Nekemias (rather than Ampelocissus or Vitis) and that the generic name Ampelocissites may be useful for fossil seeds with morphology consistent with the Ampelopsis clade that lack sufficient characters to specify placement within one of these extant genera.

INVESTIGATION OF AUBRITES THROUGH INTEGRATION OF 3D MODAL MINERALOGY WITH X-RAY MICRO-COMPUTED TOMOGRAPHY AND GEOCHEMISTRY

2018 ◽  
Author(s):  
Zoë E. Wilbur ◽  
◽  
Arya Udry ◽  
Arya Udry ◽  
Daniel M. Coleff ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Micro Computed Tomography ◽  
X Ray

scholarly journals Removal of hexavalent chromium from wastewater by Cu/Fe bimetallic nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jien Ye ◽  
Yi Wang ◽  
Qiao Xu ◽  
Hanxin Wu ◽  
Jianhao Tong ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Photoelectron Spectroscopy ◽  
Bimetallic Nanoparticles ◽  
Chemical Reduction ◽  
Particle Surface ◽  
Zerovalent Iron ◽  
Order Model ◽  
X Ray ◽  
Nanoscale Zerovalent Iron

AbstractPassivation of nanoscale zerovalent iron hinders its efficiency in water treatment, and loading another catalytic metal has been found to improve the efficiency significantly. In this study, Cu/Fe bimetallic nanoparticles were prepared by liquid-phase chemical reduction for removal of hexavalent chromium (Cr(VI)) from wastewater. Synthesized bimetallic nanoparticles were characterized by transmission electron microscopy, Brunauer–Emmet–Teller isotherm, and X-ray diffraction. The results showed that Cu loading can significantly enhance the removal efficiency of Cr(VI) by 29.3% to 84.0%, and the optimal Cu loading rate was 3% (wt%). The removal efficiency decreased with increasing initial pH and Cr(VI) concentration. The removal of Cr(VI) was better fitted by pseudo-second-order model than pseudo-first-order model. Thermodynamic analysis revealed that the Cr(VI) removal was spontaneous and endothermic, and the increase of reaction temperature facilitated the process. X-ray photoelectron spectroscopy (XPS) analysis indicated that Cr(VI) was completely reduced to Cr(III) and precipitated on the particle surface as hydroxylated Cr(OH)3 and CrxFe1−x(OH)3 coprecipitation. Our work could be beneficial for the application of iron-based nanomaterials in remediation of wastewater.

scholarly journals Investigation of opening eye defects and effects of different ripening profiles on eye structure in semi-hard cheese using X-ray micro-computed tomography

2021 ◽  
Vol 28 ◽  
pp. 100190
Author(s):  
Jaqueline Auer ◽  
Michael Reiter ◽  
Sascha Senck ◽  
Andreas Reiter ◽  
Johann Kastner ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Hard Cheese

scholarly journals 3D visualisation of voids in grapevine flowers and berries using X‐ray micro computed tomography

2021 ◽  
Author(s):  
Z. Xiao ◽  
T. Stait‐Gardner ◽  
S.A. Willis ◽  
W.S. Price ◽  
F.J. Moroni ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Micro Computed Tomography ◽  
X Ray ◽  
3D Visualisation

scholarly journals 3D Ore Characterization as a Paradigm Shift for Process Design and Simulation in Mineral Processing

2021 ◽  
Author(s):  
Pratama Istiadi Guntoro ◽  
Yousef Ghorbani ◽  
Jan Rosenkranz
Keyword(s):  
Process Design ◽  
Paradigm Shift ◽  
Mineral Processing ◽  
Analysis Tool ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Automated Mineralogy ◽  
Process Mineralogy ◽  
The Common ◽  
Ore Characterization

AbstractCurrent advances and developments in automated mineralogy have made it a crucial key technology in the field of process mineralogy, allowing better understanding and connection between mineralogy and the beneficiation process. The latest developments in X‑ray micro-computed tomography (µCT) have shown a great potential to let it become the next-generation automated mineralogy technique. µCT’s main benefit lies in its capability to allow 3D monitoring of the internal structure of the ore sample at resolutions down to a few hundred nanometers, thus excluding the common stereological error in conventional 2D analysis. Driven by the technological and computational progress, µCT is constantly developing as an analysis tool and successively it will become an essential technique in the field of process mineralogy. This study aims to assess the potential application of µCT systems, for 3D ore characterization through relevant case studies. The opportunities and platforms that µCT 3D ore characterization provides for process design and simulation in mineral processing are presented.

Identification of corrosion products and 3D distribution in reinforced concrete using X-ray micro computed tomography

2019 ◽  
Vol 207 ◽  
pp. 304-315 ◽  
Author(s):  
Guohao Fang ◽  
Weijian Ding ◽  
Yuqing Liu ◽  
Jianchao Zhang ◽  
Feng Xing ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Reinforced Concrete ◽  
Corrosion Products ◽  
Micro Computed Tomography ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document