Mesoscale experimental study on chemical composition,pore size distribution,and permeability of tailings     

Zengguang Xu  Yang Yang  Junrui Chai  Xuemin Yang  Yuan Qin  Yanlong Li 《Environmental Earth Sciences》2017,76(20):707

To study the seepage characteristics of tailing sand, an indoor sand column test was performed with three kinds of tailing sand obtained from Henan and Shaanxi provinces, China. River sand, quartz sand, and glass beads were also employed for comparison. Using the nuclear magnetic resonance, the researchers studied pore size distribution and permeability under different hydraulic gradients. The chemical composition and particle morphology were analyzed by energy-dispersive spectrometry and X-ray diffraction. The results were as follows. (1) The three kinds of tailings sand are small in diameter, mainly in the range from 0.15 to 0.5 mm. Their diameter distribution is more concentrated than river sand. The surface of tailing sand is rough. As for chemical composition, tailing sand contains many kinds of metal elements. (2) With hydraulic gradient increasing, the micropores in the tailings samples become fewer, the larger pores grow in number, and the peak of the pore size distribution changes to the left; blocking is more obvious. (3) The small pores gradually decrease during the test. Under the influence of groundwater pressure, the smaller gravel could migrate and block tiny pores. The structure of particle arrangement becomes denser. Therefore, it would prevent the seepage liquid from passing through the medium. The permeability coefficient K decreases.  相似文献   

Understanding the characteristic of GLONASS inter-frequency clock bias using both FDMA and CDMA signals     

Zhang  Fan  Chai  Hongzhou  Li  Linyang  Wang  Min  Feng  Xu  Du  Zhenqiang 《GPS Solutions》2022,26(2):1-19

GPS Solutions - High-frequency global navigation satellite system (GNSS) observations are of great significance for structural health monitoring. At present, most studies on high-frequency GNSS...  相似文献