Comprehensive evaluation and interpretation of mercury intrusion porosimetry data of coals based on fractal theory, Tait equation and matrix compressibility

Fuel ◽  
2021 ◽  
Vol 298 ◽  
pp. 120823
Author(s):  
Quanlin Yang ◽  
Junhua Xue ◽  
Wei Li ◽  
Xuanhong Du ◽  
Qian Ma ◽  
...  
2020 ◽  
pp. 16-23
Author(s):  
QI DAOZHENG ◽  
GU CONG ◽  
FU JIAJIA ◽  
WANG YAO

The clay-sand mixtures with diferent partcle sizes were prepared to investgate partcle and pore characteristcs. The microstructure characteristcs of the sand-clay mixtures were studied by the Mercury Intrusion Porosimetry (MIP) test and Scanning Electron Microscopy (SEM). Image-Pro Plus (IPP) image processing sofware was used to quantfy SEM images which investgated the micro-mechanism of structural evoluton of mixtures under diferent gradatons. The research results indicate that the units of mixtures develop from platelets and honeycomb to agglomerated and granular with the increase of sand content. The contact between partcles transits from face-face contacts to edge-face and pointface contacts. This artcle evaluated the fractal characteristc of partcle and pore structure based on the fractal theory. With the increase Circularity of the partcles, the ordered arrangement of the partcles in the mixed soil is further reduced. In general, the distributon of pores changes from intergranular pores to pores in aggregate, which provides a theoretcal basis for further study on the micro-macro correlaton of mixtures.


2010 ◽  
Vol 168-170 ◽  
pp. 615-618
Author(s):  
Zhi Qin Du ◽  
Wei Sun

The effect of different quantity of air-entraining agent on the impermeability of cement-based materials are studied in this paper. Impermeability test and mercury intrusion porosimetry (MIP) method were used to characterize the impermeability and pore structures. The fractal dimension is used to describe the characteristic of pore structure and calculated by the data of MIP experiment. The result shows that owing to the improvement of pore structure, the impermeability performance of the cement-based composites is noticeably enhanced when air-entraining agent is added with appropriate quantity.


2011 ◽  
Vol 197-198 ◽  
pp. 662-666
Author(s):  
Qing Jun Zhang ◽  
Wen Ling Mo ◽  
Yuan Liang Li ◽  
Yu Zhu Zhang

The pore in the sinter is an important character. Because of multiphase and asymmetry in the sinter, the structure of the pore is very complex. To study the character of the pore effectively, the method of mercury intrusion porosimetry is applied to measure the pore in the sinter, and the results are dealt with by the fractal theory. The results prove that the pores in the sinter are actually fractal structure when the size of the pores is more than 204.5 nm because their curves in the log-log plot are linear, and some curves qualified with the linearity obviously possess of the segment linearity character. According to the calculation of the fractal D, the relationship of the strength and fractal D will be established.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1823
Author(s):  
Won-Kyung Kim ◽  
Young-Ho Kim ◽  
Gigwon Hong ◽  
Jong-Min Kim ◽  
Jung-Geun Han ◽  
...  

This study analyzed the effects of applying highly concentrated hydrogen nanobubble water (HNBW) on the workability, durability, watertightness, and microstructure of cement mixtures. The number of hydrogen nanobubbles was concentrated twofold to a more stable state using osmosis. The compressive strength of the cement mortar for each curing day was improved by about 3.7–15.79%, compared to the specimen that used general water, when two concentrations of HNBW were used as the mixing water. The results of mercury intrusion porosimetry and a scanning electron microscope analysis of the cement paste showed that the pore volume of the specimen decreased by about 4.38–10.26%, thereby improving the watertightness when high-concentration HNBW was used. The improvement in strength and watertightness is a result of the reduction of the microbubbles’ particle size, and the increase in the zeta potential and surface tension, which activated the hydration reaction of the cement and accelerated the pozzolanic reaction.


Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Na Zhang ◽  
Fangfang Zhao ◽  
Pingye Guo ◽  
Jiabin Li ◽  
Weili Gong ◽  
...  

Porosity and permeability of two typical sedimentary rocks in coal bearing strata of underground coal mines in China, i.e., mudrocks and fine-grained sandstones, were comprehensively investigated by multiple experimental methods. Measured porosity averages of the helium gas porosity (φg), MIP porosity (φMIP), water porosity (φw), and NMR porosity (φNMR) of the twelve investigated rock samples range from 1.78 to 16.50% and the measured gas permeabilities (Kg) range from 0.0003 to 2.4133 mD. Meanwhile, pore types, pore morphologies, and pore size distributions (PSD) were determined by focused ion beam scanning electron microscopy (FIB-SEM), mercury intrusion porosimetry (MIP), and low-field nuclear magnetic resonance (NMR). FIB-SEM image analyses showed that the mineral matrix pores including interparticle (interP) and intraparticle (intraP) pores with varied morphologies are the dominant pore types of the investigated rock samples while very few organic matter (OM) pores were observed. Results of the MIP and the full water-saturated NMR measurements showed that the PSD curves of the mudrock samples mostly present a unimodal pattern and nanopores with pore diameter less than 0.1 μm are their predominant pore type, while the PSD curves of the fine-grained sandstone samples are featured by a bimodal distribution. Furthermore, comparison of the full water-saturated and irreducible-water-saturated NMR measurements indicated that pores in the mudrocks are solely adsorption pores (normally pore size < 0.1 μm) whereas apart from a fraction of adsorption pores, a large part of the pores in the sandstone sample with relatively high porosity are seepage pores (normally pore size > 0.1 μm). Moreover, the PSD curves of NMR quantitatively converted from the NMR T2 spectra by T2Pc and weighted arithmetic mean (WAM) methods are in good agreement with the PSD curves of MIP. Finally, the applicability of three classic permeability estimation models based on MIP and NMR data to the investigated rock samples was evaluated.


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