scholarly journals Full-scale pore size distribution features of uranium-bearing sandstone in the northwest of Xinjiang, China

2021 ◽  
Vol 8 (5) ◽  
pp. 202036
Author(s):  
Sheng Zeng ◽  
Hao Li ◽  
Ni Zhang ◽  
Bing Sun ◽  
Jinzhu Li ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Pore Volume ◽  
Gas Adsorption ◽  
Full Scale ◽  
Uranium Recovery ◽  
Distribution Features ◽  
Pore Types

As an important nuclear fuel, uranium in sandstone uranium deposits is mainly extracted by in situ leaching. The porosity of sandstone is one of the important indexes determining in situ leaching efficiency. Moreover, the microscopic pore size distribution (PSD) of the uranium-bearing layer has an important effect on porosity. It is necessary to feature the pore structure by various techniques because of the different pore types and sizes in the uranium layer. In this paper, combined with nitrogen gas adsorption, nuclear magnetic resonance techniques and scanning electron microscopy, the full-scale PSD features of uranium-bearing sandstone in the northwest of Xinjiang are effectively characterized. The results show that pores structure of uranium-bearing sandstone include dissolution pores ( d ≤ 50 nm), intergranular pores (50 nm < d ≤ 200 µm) and microfractures. Intergranular pores of 60 nm and 1 µm are the significant contributors to pore volume. The effects of the pore volume of two pore types (dissolution pores and intergranular pores) on the porosity of uranium-bearing sandstone are analysed. The results show that intergranular pores have the greater influence on the porosity and are positively correlated to the porosity. Dissolution pores have little effect on the porosity, but it is one of the key factors for improving uranium recovery. Moreover, the greater the difference of PSD between sandstones, the stronger the interlayer heterogeneity of uranium-bearing sandstone. This kind of interlayer heterogeneity leads to the change of permeability in the horizontal direction of strata. It provides a basis for a reasonable setting of well type and well spacing parameters.

The relationship between geotechnical index properties and the pore-size distribution of compacted clayey silts

2015 ◽  
Vol 22 (6) ◽  
Author(s):  
Nazile Ural
Keyword(s):  
Specific Surface ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Correlation Coefficients ◽  
Liquid Limit ◽  
Index Properties

AbstractIn this study, the relationships between geotechnical index properties and the pore-size distribution of compacted natural silt and artificial soil mixtures, namely, silt with two different clays and three different clay percentages (10%, 20%, and 40%), were examined and compared. Atterberg’s limit tests, standard compaction tests, mercury intrusion porosimetry, X-ray diffraction, scanning electron microscopy (SEM) analysis, and Brunauer-Emmett-Teller specific surface analysis were conducted. The results show that the liquid limit, the cumulative pore volume, and specific surface area of artificially mixed soils increase with an increase in the percentage of clay. The cumulative pore volume and specific surface area with geotechnical index properties were compared. High correlation coefficients were observed between the specific areas and both the liquid limit and the plasticity index, as well as between the cumulative pore volume and both the clay percentage and the

Porosity and pore size distribution of shales: a case study of the Carynginia Formation, Perth Basin, Western Australia

2017 ◽  
Vol 57 (2) ◽  
pp. 660
Author(s):  
M. Nadia Testamanti ◽  
Reza Rezaee ◽  
Jie Zou
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Gas Adsorption ◽  
Pore Network ◽  
Pore Sizes ◽  
Wide Range ◽  
Pore Characterisation ◽  
Shale Reservoirs ◽  
Mercury Injection Capillary Pressure

The evaluation of the gas storage potential of shale reservoirs requires a good understanding of their pore network. Each of the laboratory techniques used for pore characterisation can be applied to a specific range of pore sizes; but if the lithology of the rock is known, usually one suitable method can be selected to investigate its pore system. Shales do not fall under any particular lithological classification and can have a wide range of minerals present, so a combination of at least two methods is typically recommended for a better understanding of their pore network. In the laboratory, the Low-Pressure Nitrogen Gas Adsorption (LP-N2-GA) technique is typically used to examine micropores and mesopores, and Mercury Injection Capillary Pressure (MICP) tests can identify pore throats larger than 3 nm. In contrast, a wider range of pore sizes in rock can be screened with Nuclear Magnetic Resonance (NMR), either in laboratory measurements made on cores or through well logging, provided that the pores are saturated with a fluid. The pore network of a set of shale core samples from the Carynginia Formation was investigated using a combination of laboratory methods. The cores were studied using the NMR, LP-N2-GA and MICP techniques, and the experimental porosity and pore size distribution results are presented. When NMR results were calibrated with MICP or LP-N2-GA measurements, then the pore size distribution of the shale samples studied could be estimated.

Carbon-Doped Hollow Titania with Tuneable Shell Architecture for Supercapacitors

2016 ◽  
Vol 69 (2) ◽  
pp. 183 ◽  
Author(s):  
Juanrong Chen ◽  
Fengxian Qiu ◽  
Ying Zhang ◽  
Shunsheng Cao
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
High Performance ◽  
Electrode Materials ◽  
Carbon Doping ◽  
Narrow Pore Size Distribution ◽  
Carbon Doped

A new trend in supercapacitor research has focussed on the construction of inexpensive electrode materials with high capacitor performances. In this study, we demonstrate the successful preparation of carbon-doped hollow titania spheres. The as-prepared titania spheres not only exhibit an advantage over existing methods because they are created in situ by directly carbonizing cationic polystyrene templates without the addition of carbon precursors, but also feature a narrow pore size distribution and a tuneable shell architecture. When the materials were applied as supercapacitor anodes, the electrochemical results reveal the superior performances of the supercapacitors over that of commercial P25. The higher performances were attributed to carbon doping. Thus, the reported C-doped hollow titania shows more potential as electrode materials for high-performance supercapacitors.

Water Adsorption in Nanoporous Carbon Characterized by in Situ NMR: Measurements of Pore Size and Pore Size Distribution

2014 ◽  
Vol 118 (16) ◽  
pp. 8474-8480 ◽  
Author(s):  
Hai-Jing Wang ◽  
Alfred Kleinhammes ◽  
Thomas P. McNicholas ◽  
Jie Liu ◽  
Yue Wu
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Water Adsorption ◽  
Nanoporous Carbon ◽  
In Situ Nmr

Biphasic calcium phosphate scaffolds with controlled pore size distribution prepared by in-situ foaming

2019 ◽  
Vol 95 ◽  
pp. 363-370 ◽  
Author(s):  
Lenka Novotna ◽  
Lukas Kucera ◽  
Ales Hampl ◽  
Daniel Drdlik ◽  
Jaroslav Cihlar ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Biphasic Calcium Phosphate
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