scholarly journals A new X-ray transparent flow-through reaction cell for a μ-CT-based concomitant surveillance of the reaction progress of hydrothermal mineral-fluid interactions

2016 ◽  
Author(s):  
Wolf-Achim Kahl ◽  
Christian Hansen ◽  
Wolfgang Bach

Abstract. A new flow-through reaction cell consisting of an X-ray transparent semicrystalline thermoplastic has been developed for percolation experiments. Core holder, tubing and all confining parts are designed of PEEK (polyetheretherketone) to allow concomitant surveillance of the reaction progress by X-ray microtomography (μ-CT). With this cell setup, corrosive or oversaturated fluids can be forced through rock cores (up to ∅ 19 mm) or powders at pressures up to 100 bars and temperatures up to 200 °C. The reaction progress of the experiment can be monitored without dismantling the sample from the core holder. The combination of this flow-through reaction cell setup with a laboratory X-ray μ-CT system facilitates on-demand monitoring of the reaction progress of (long-term) hydrothermal experiments in the own laboratory, keeping interruption times as short as possible. To demonstrate both the suitability of the cell construction material for X-ray imaging purposes and the experimental performance of the flow-through system, we report the virtually non-existent bias of the PEEK cell setup with distinctive X-ray observations (e. g., differing states of pore fillings: air vs. fluid; detection of delicate fabric elements: filigree zeolitic crystals overgrowing weathered muscovite), and the monitoring of the gypsum/anhydrite transition as a case study of a 4D fabric evolution.

Solid Earth ◽  
2016 ◽  
Vol 7 (2) ◽  
pp. 651-658 ◽  
Author(s):  
Wolf-Achim Kahl ◽  
Christian Hansen ◽  
Wolfgang Bach

Abstract. A new flow-through reaction cell consisting of an X-ray-transparent semicrystalline thermoplastic has been developed for percolation experiments. Core holder, tubing and all confining parts are constructed using PEEK (polyetheretherketone) to allow concomitant surveillance of the reaction progress by X-ray microtomography (μ-CT). With this cell setup, corrosive or oversaturated fluids can be forced through rock cores (up to ∅ 19 mm) or powders at pressures up to 100 bar and temperatures up to 200 °C. The reaction progress of the experiment can be monitored without dismantling the sample from the core holder. The combination of this flow-through reaction cell setup with a laboratory X-ray μ-CT system facilitates on-demand monitoring of the reaction progress of (long-term) hydrothermal experiments in the own laboratory, keeping interruption times as short as possible. To demonstrate both the suitability of the cell construction material for X-ray imaging purposes and the experimental performance of the flow-through system, we report the virtually non-existent bias of the PEEK cell setup with distinctive X-ray observations (e.g., differing states of pore fillings: air vs. fluid; detection of delicate fabric elements: filigree zeolite crystals overgrowing weathered muscovite), and the monitoring of the gypsum/anhydrite transition as a case study of a 4-D fabric evolution.


2011 ◽  
Vol 44 (2) ◽  
pp. 429-432 ◽  
Author(s):  
Andrew J. Wall ◽  
Peter J. Heaney ◽  
Ryan Mathur ◽  
Jeffrey E. Post ◽  
Jonathan C. Hanson ◽  
...  

A non-metallic flow-through reaction cell is described, designed forin situtime-resolved X-ray diffraction coupled with stable isotope analysis. The experimental setup allows the correlation of Cu isotope fractionation with changes in crystal structure during copper sulfide dissolution. This flow-through cell can be applied to many classes of fluid–mineral reactions that involve dissolution or ion exchange.


Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 990
Author(s):  
Fatemeh Nikkhou ◽  
Fang Xia ◽  
Xizhi Yao ◽  
Idowu A. Adegoke ◽  
Qinfen Gu ◽  
...  

A flow-through reaction cell has been developed for studying minerals leaching by in-situ time-resolved powder X-ray diffraction, allowing for a better understanding of the leaching mechanisms and kinetics. The cell has the capability of independent control of temperature (up to 95 °C) and flow rate (>0.5 mL min−1) for atmospheric pressure leaching. It was successfully tested at the powder diffraction beamline at the Australian Synchrotron. Galena powder was leached in a citrate solution under flow-through condition at a flow rate of 0.5 mL min−1, while diffraction patterns were collected during the entire leaching process, showing rapid galena dissolution without the formation of secondary mineral phases. The flow-through cell can be used to study leaching processes of other ore minerals.


2011 ◽  
Vol 19 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Pilar Ferrer ◽  
Iván da Silva ◽  
Juan Rubio-Zuazo ◽  
Belén F. Alfonso ◽  
Camino Trobajo ◽  
...  

A portable powder–liquid high-corrosion-resistant reaction cell has been designed to followin situreactions by X-ray powder diffraction (XRD) and X-ray absorption spectroscopy (XAS) techniques. The cell has been conceived to be mounted on the experimental stations for diffraction and absorption of the Spanish CRG SpLine-BM25 beamline at the European Synchrotron Radiation Facility. Powder reactants and/or products are kept at a fixed position in a vertical geometry in the X-ray pathway by a porous membrane, under forced liquid reflux circulation. Owing to the short pathway of the X-ray beam through the cell, XRD and XAS measurements can be carried out in transmission configuration/mode. In the case of the diffraction technique, data can be collected with either a point detector or a two-dimensional CCD detector, depending on specific experimental requirements in terms of space or time resolution. Crystallization processes, heterogeneous catalytic processes and several varieties of experiments can be followed by these techniques with this cell. Two experiments were carried out to demonstrate the cell feasibility: the phase transformations of layered titanium phosphates in boiling aqueous solutions of phosphoric acid, and the reaction of copper carbonate and L-isoleucine amino acid powders in boiling aqueous solution. In this last case the shrinking of the solid reactants and the formation of Cu(isoleucine)2is observed. The crystallization processes and several phase transitions have been observed during the experiments, as well as an unexpected reaction pathway.


1987 ◽  
Vol 112 ◽  
Author(s):  
M. A. Gardiner ◽  
G. H. Kacandes ◽  
G. C. Ulmer ◽  
D. E. Grandstaff

AbstractCohassett basalt was reacted with synthetic Hanford groundwater in a Dickson rocking autoclave at 300°C and 30 MPa for ca. 7600 hours. During the experiment fresh solution was twice reinjected into the reaction cell, raising the nominal water:rock mass ratio from 50:1 to 140:1. The reinjection experiment is intermediate between closed-system Dickson experiments and flow-through tests in that the fluid and solids can remain in contact for extended periods of time before the solution is replaced. This allows more time for equilibrium to be approached. Data from this experiment suggest:(1) After reinjection many solution parameters quickly (hrs-days) returned to near preinjection values. (2) The redox buffer capacity of the basalt was not exceeded, i.e. fO2 values remained near magnetite-hematite values, although the nominal water:rock mass ratio was raised to ca. 140 during the experiment. (3) After reinjection the stable high-temperature pH value was only slightly less than the initial pH value. (4) The silica concentration stabilized near apparent quartz saturation rather than the cristobalite saturation value found in closed-system experiments. (5) Short-term relationships between cations appear to be controlled by ionexchange between the solutions and clay minerals.Reaction products identified from the experiment include: Fesmectite, illite, hematite, minor cristobalite and possibly Ti-maghemite.


Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).


Author(s):  
James F. Mancuso ◽  
William B. Maxwell ◽  
Russell E. Camp ◽  
Mark H. Ellisman

The imaging requirements for 1000 line CCD camera systems include resolution, sensitivity, and field of view. In electronic camera systems these characteristics are determined primarily by the performance of the electro-optic interface. This component converts the electron image into a light image which is ultimately received by a camera sensor.Light production in the interface occurs when high energy electrons strike a phosphor or scintillator. Resolution is limited by electron scattering and absorption. For a constant resolution, more energy deposition occurs in denser phosphors (Figure 1). In this respect, high density x-ray phosphors such as Gd2O2S are better than ZnS based cathode ray tube phosphors. Scintillating fiber optics can be used instead of a discrete phosphor layer. The resolution of scintillating fiber optics that are used in x-ray imaging exceed 20 1p/mm and can be made very large. An example of a digital TEM image using a scintillating fiber optic plate is shown in Figure 2.


Author(s):  
Ann LeFurgey ◽  
Peter Ingram ◽  
J.J. Blum ◽  
M.C. Carney ◽  
L.A. Hawkey ◽  
...  

Subcellular compartments commonly identified and analyzed by high resolution electron probe x-ray microanalysis (EPXMA) include mitochondria, cytoplasm and endoplasmic or sarcoplasmic reticulum. These organelles and cell regions are of primary importance in regulation of cell ionic homeostasis. Correlative structural-functional studies, based on the static probe method of EPXMA combined with biochemical and electrophysiological techniques, have focused on the role of these organelles, for example, in maintaining cell calcium homeostasis or in control of excitation-contraction coupling. New methods of real time quantitative x-ray imaging permit simultaneous examination of multiple cell compartments, especially those areas for which both membrane transport properties and element content are less well defined, e.g. nuclei including euchromatin and heterochromatin, lysosomes, mucous granules, storage vacuoles, microvilli. Investigations currently in progress have examined the role of Zn-containing polyphosphate vacuoles in the metabolism of Leishmania major, the distribution of Na, K, S and other elements during anoxia in kidney cell nuclel and lysosomes; the content and distribution of S and Ca in mucous granules of cystic fibrosis (CF) nasal epithelia; the uptake of cationic probes by mltochondria in cultured heart ceils; and the junctional sarcoplasmic retlculum (JSR) in frog skeletal muscle.


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