scholarly journals Physical-mechanical Properties and Radon Exhalation of Fiber-reinforced Uranium Tailings Geopolymer Solidified Bodies

2021 ◽  
Author(s):  
Fuliang Jiang ◽  
Biao Tan ◽  
Zhe Wang ◽  
Yong Liu ◽  
Yuying Hao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Basalt Fiber ◽  
Volume Resistivity ◽  
National Standard ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Radon Exhalation ◽  
Pva Fiber ◽  
Uranium Tailings

Abstract Uranium tailing ponds are a potential major source of radioactive pollution. Solidification treatment of uranium tailings can control the diffusion and migration of radioactive elements in uranium tailings to safeguard the surrounding ecological environment. Literature review and field investigation were conducted in this study prior to fabricating 11 solidified uranium tailings samples with different proportions with PVA fiber, basalt fiber, metakaolin, and fly ash. The samples’ pore structure, volume resistivity, compressive strength, and radon exhalation rate variations were analyzed. The pore size of the solidified samples is mainly between 1–50 nm, the pore volume is between 0.726–1.750 cm3/g, the volume resistivity is between 1411.33-1937.33 Ω·m, and the compressive strength is between 20.61–36.91 MPa. The radon exhalation rate is between 0.0397–0.0853 Bq·m2·s− 1, which is lower than the national standard. Based on a comprehensive analysis of the physical and mechanical properties and radon exhalation rate of the solidified samples, the basalt fiber is found to outperform PVA fiber overall. The solidification effect is optimal when the 0.6% basalt fiber is added.

Noise Reduction Treatment and Analysis of Accumulated Radon Concentration in Uranium-Like Rock Based on Wavelet Theory

2018 ◽  
Author(s):  
Fuliang Jiang ◽  
Wenchao Yang ◽  
Ming Li ◽  
Xiangyang Li ◽  
Changshou Hong
Keyword(s):  
Radon Concentration ◽  
Raw Materials ◽  
Uranium Mine ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Wavelet Theory ◽  
Actual Measurement ◽  
Radon Exhalation ◽  
Single Side ◽  
Uranium Tailings

Based on the principle of similarity, uranium ore samples were prepared from raw materials such as uranium tailings, quartz sand and refined iron powder, and then the samples were treated with different packages for measuring the sample accumulated radon concentration. In the actual measurement process, due to the characteristics of radionuclide decay, instrument reasons and human factors, the data will be a certain deviation. Therefore, the method of wavelet analysis is used to denoise the accumulated radon concentration and obtain radon exhalation rate. The results of the study show: the correlation coefficient of cumulative radon concentration fitted by wavelet denoising is improved greatly, and all of them are above 0.99, the recalculated radon exhalation rate of the single side of the sample is decreased by 0.06Bq · m−2 · s−1, and double-edged is decreased by 0.02Bq · m−2 · s−1. The experiment proved that wavelet theory can be used to correct calculated value of radon exhalation rate of uranium-like rock. At the same time, it provides a new method for further study of uranium mine radiation protection parameters.

Compressive strength, water absorption, water sorptivity and surface radon exhalation rate of silica fume and fly ash based mortar

2019 ◽  
Vol 23 ◽  
pp. 369-376 ◽  
Author(s):  
Daniel Hatungimana ◽  
Caner Taşköprü ◽  
Mutlu İçhedef ◽  
Müslim Murat Saç ◽  
Şemsi Yazıcı
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Water Absorption ◽  
Silica Fume ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Radon Exhalation ◽  
Water Sorptivity

scholarly journals Laboratory Experimental Laws for the Radon Exhalation of Similar Uranium Samples with Low-Frequency Vibrations

2018 ◽  
Vol 10 (8) ◽  
pp. 2937 ◽  
Author(s):  
Zi-qi Cai ◽  
Xiang-yang Li ◽  
Bo Lei ◽  
Jing-fan Yuan ◽  
Chang-shou Hong ◽  
...  
Keyword(s):  
Low Frequency ◽  
Silicon Powder ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Blank Group ◽  
Closed Chamber ◽  
Radon Exhalation ◽  
Damage Degree ◽  
Low Frequency Vibration ◽  
Uranium Tailings

It is the fact that there are lots of hazard incidents in underground uranium mines caused by radon but in-suit uranium samples were difficult to collect. Based on closed chamber method, three similar samples in different sealed ways were made in a laboratory with different material rations, namely uranium tailings, quartz sand, cement, iron powder and silicon powder to measure the radon concentrations with and without low-frequency vibrations, which was used by the experimental device for low-frequency vibration diffusion of radon. The results showed that the radon exhalation coming from the similar samples was influenced by the low frequency vibration; the results are presented as two-stage variations compared with the blank group. The radon exhalation increased with the rising vibration frequency when the frequency was 50 to 70 Hz, but fell slowly after reaching the peak radon exhalation rate. Analyses of the relations between the rock damage degree, changes in porosity and the occurrence of an inflection point in the radon exhalation rate in the samples found that they also increased when the frequency was between 0 to 80 in sample 3. The maximum porosity of the third samples was about 4.8% with a low-frequency vibration 60 Hz, while the maximum damage degree was about 0.07 at 50 Hz.

FRACTAL AND CHAOS ANALYSIS FOR DYNAMICS OF RADON EXHALATION FROM URANIUM MILL TAILINGS

Fractals ◽  
2016 ◽  
Vol 24 (03) ◽  
pp. 1650029 ◽  
Author(s):  
YONGMEI LI ◽  
WANYU TAN ◽  
KAIXUAN TAN ◽  
ZEHUA LIU ◽  
YANSHI XIE
Keyword(s):  
Time Series ◽  
Lyapunov Exponent ◽  
Hurst Exponent ◽  
Correlation Dimension ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Radon Exhalation ◽  
Mill Tailings ◽  
Uranium Tailings ◽  
Uranium Mill Tailings

Tailings from mining and milling of uranium ores potentially are large volumes of low-level radioactive materials. A typical environmental problem associated with uranium tailings is radon exhalation, which can significantly pose risks to environment and human health. In order to reduce these risks, it is essential to study the dynamical nature and underlying mechanism of radon exhalation from uranium mill tailings. This motivates the conduction of this study, which is based on the fractal and chaotic methods (e.g. calculating the Hurst exponent, Lyapunov exponent and correlation dimension) and laboratory experiments of the radon exhalation rates. The experimental results show that the radon exhalation rate from uranium mill tailings is highly oscillated. In addition, the nonlinear analyses of the time series of radon exhalation rate demonstrate the following points: (1) the value of Hurst exponent much larger than 0.5 indicates non-random behavior of the radon time series; (2) the positive Lyapunov exponent and non-integer correlation dimension of the time series imply that the radon exhalation from uranium tailings is a chaotic dynamical process; (3) the required minimum number of variables should be five to describe the time evolution of radon exhalation. Therefore, it can be concluded that the internal factors, including heterogeneous distribution of radium, and randomness of radium decay, as well as the fractal characteristics of the tailings, can result in the chaotic evolution of radon exhalation from the tailings.

Analysis of the Ventilation Effects on Radon-222 Exhalation in a Dead-End Tunnel

2015 ◽  
Vol 713-715 ◽  
pp. 304-313
Author(s):  
Shu Guang Wang ◽  
Wei Yang ◽  
Qing Chen ◽  
Jian Hua Chen ◽  
Cong Han
Keyword(s):  
High Temperature ◽  
Ambient Temperature ◽  
Natural Ventilation ◽  
Weather Conditions ◽  
Calculation Model ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Radon Exhalation ◽  
Exhaust Ventilation ◽  
Dead End

The regularity of radon exhalation rate in the over-broken granite tunnel is susceptible to weather conditions and ventilation styles. Based on the calculation model of radon exhalation in tunnel, some experiments have been carried out to analyze the variations of radon exhalation in cases of natural ventilation, blowing ventilation and exhaust ventilation separately. The results show that there is a linear relation between the radon exhalation and the natural ventilation quantity, and also between the radon exhalation and the ambient temperature; the radon exhalation in the case of exhaust ventilation is 63% higher than that in the blowing case under the condition of the same ventilation quantity and ambient temperature. Therefore, it is suggested that operation in the tunnel in high temperature be avoided in summer, and the blowing ventilation be adopted as an effective way for ventilation.

scholarly journals Outdoor 222Rn behaviour in different areas of Slovakia

Nukleonika ◽  
2016 ◽  
Vol 61 (3) ◽  
pp. 281-288 ◽  
Author(s):  
Karol Holý ◽  
Monika Műllerová ◽  
Martin Bulko ◽  
Oľga Holá ◽  
Terézia Melicherová
Keyword(s):  
Time Series ◽  
Significant Influence ◽  
Activity Concentration ◽  
Sandy Soils ◽  
Simple Approach ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Hilly Terrain ◽  
Radon Exhalation ◽  
Linear Dependency

Abstract Radon activity concentration (RAC) in the outdoor atmosphere was monitored in four localities of Slovakia. The distance between the localities were up to 130 km. The localities had a diverse orography, ranging from flatland to hilly terrain. A significant influence of orography and 226Ra and 222Rn content in soil on diurnal time series of RAC was found. A simple approach of determining radon exhalation rate from soil based on the increase of RAC from daily minima to maxima and removal characteristic of radon is presented. A linear dependency between radon exhalation rate from the soil and RAC in the soil gas at a depth of 0.8 m was found for sandy soils.

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