Insight into the water–rock interaction process and purification mechanism of mine water in underground reservoir of Daliuta coal mine in China

Author(s):  
Binbin Jiang ◽  
Ju Gao ◽  
Kun Du ◽  
Xu Deng ◽  
Kai Zhang
2021 ◽  
Author(s):  
Binbin Jiang ◽  
Ju Gao ◽  
Kun Du ◽  
Xu Deng ◽  
Kai Zhang

Abstract The process of water rock interaction and the purification mechanism of mine water quality were not clear after being stored in underground reservoir. This study based on the analysis of the hydrochemical characteristics of the reservoir water samples and the characterization of the rock samples, combined with PHREEQC analysis, the mechanism of water quality purification of mine water was discussed. The results showed that the rocks in the underground reservoir had layered silicate structure and flaky kaolinite structure, with some irregular edges and micro cracks, and higher specific surface area and total pore volume. These characteristics made the rocks had a certain adsorption and removal capacity for heavy metal ions and other pollutants in the mine water. The water rock interaction, such as the dissolution of albite and halite, the precipitation of gypsum and kaolinite, and the cation exchange, resulted in the increase of the concentration of Na+ and the decrease of the concentration of Ca2+, Mg2+ and TDS in the outlet water. This study also showed that PHREEQC analysis can be used to analyze the water rock interaction of coal mine underground reservoir and obtained more detailed information.


2014 ◽  
Vol 78 (6) ◽  
pp. 1473-1477
Author(s):  
Jan Přikryl ◽  
Andri Stefánsson

The interaction of CO2-rich water with olivine was studied using geochemical reaction modelling in order to gain insight into the effects of temperature, acid supply (CO2) and extent of reaction on the secondary mineralogy, water chemistry and mass transfer. Olivine (Fo93) was dissolved at 150 and 250ºC and pCO2 of 2 and 20 bar in a closed system and an open system with secondary minerals allowed to precipitate. The progressive water–rock interaction resulted in increased solution pH, with gradual carbonate formation starting at pH 5 and various Mg-OH and Mg-Si minerals becoming dominant at pH>8. The major factor determining olivine alteration is the pH of the water. In turn, the pH value is determined by acid supply, reaction progress and temperature.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Huafeng Deng ◽  
Yinchai Zhang ◽  
Yongyan Zhi ◽  
Lingling Duan ◽  
Jianlin Li ◽  
...  

During the long-term reservoir operation, the seismic capability and dynamic response characteristics of the bank slope are of great importance to its safety evaluation content. Aimed at typical bank slopes, considering reservoir water level fluctuation and soaking-air drying cyclic interaction, an experiment has been designed and conducted. In addition, the cyclic loading test with different stress amplitudes was carried out in different water-rock cycles. The laboratory results indicate that (1) during the immersion-air dry circulation process, the damping ratio and damping coefficient of sandstone gradually increased while the dynamic elastic modulus decreased. It is obvious that the dynamic elastic modulus of sandstone decreases dramatically during the immersion-air dry circulation process, especially in the first six periods. Also, its variation curve fits with the logarithmic curve. (2) When the cyclic load stress amplitude increases from 10 MPa to 35 MPa, the damping ratio and coefficient of the rock sample gradually decreased while dynamic elastic modulus increased. each dynamic parameter shows a more obvious variation trend when the stress amplitude is lower than 25 MPa. (3) During the water-rock interaction process, the closely knit microstructure of rock gradually becomes loose and porous, which resulted in the degradation of macroscopic physical and mechanical properties of sandstone. (4) In the analysis of the seismic response of the bank slope, the actual water-rock interaction process and the seismic level of the bank slope should be more considered. To find out further accurate reflection in the earthquake resistance and dynamic response of the bank slope, it is necessary to select the reasonable dynamic parameter to carry out seismic research.


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