期刊：
Fractal and Fractional,2023年7(10):704- ISSN：2504-3110
通讯作者：
Tan, KX
作者机构：
[Cai, Qiue] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Cai, Qiue; Zeng, Sheng; Tan, Kaixuan] Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Zhu, Junjie] Cent South Univ, Sch Geosci & Info Phys, Changsha 410083, Peoples R China.
通讯机构：
[Tan, KX ] U;Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Peoples R China.
关键词：
element concentration–area (C-A);multifractal;singularity exponent;uranium ore;uranium distribution characteristics
摘要：
Based on an analysis of the spatial distribution of uranium grade in 338 boreholes of a uranium deposit in Xinjiang, the enrichment and spatial variation of uranium ore in two stopes of the deposit are discussed using multifractal theory. The distribution characteristics of the uranium ore of the two stopes are studied by multifractal parameters: the scaling exponent of mass tau(q), the scaling exponent alpha(q) of each sub-set and its corresponding fractal dimension f(alpha), the fractal dimension D0 and information dimension D1. The differences of uranium distribution in the two stopes can be quantified well by using multifractal spectrum and multifractal parameters such as Delta alpha, Delta f and R. After a comprehensive multifractal distribution analysis, 10 m x 10 m is defined as a fence unit, and the window sizes epsilon=3,6,9MIDLINE HORIZONTAL ELLIPSIS,45 are set; the singularity exponents alpha of the two stopes are calculated by using this element concentration-area method. The results show that the multifractal theory and model can organically combine spatial structure information, scale change information and anisotropy information to obtain low-grade and weak mineral resources information and can effectively distinguish complex and superimposed anomalies. This will provide a basis for the local concentration and spatial variation rules of uranium distribution and the design of the parameters of the leaching uranium mining well site.
摘要：
Radon in the household water (especially groundwater) which is an important source of indoor radon, has become a potential health hazard to residents. In this study, radon concentrations in groundwater sampled from five villages near Dongpo W-polymetallic metallogenic region were measured using RAD-7 detector with RAD H2O accessory, and the effect of regional geology and mineralization on radon concentration in groundwater was studied. In addition, we also estimated the radiation doses received by people via ingestion of radon in water and inhalation of the radon from the indoor air while using water. The results show that the radon concentration in groundwater samples varies from 1.29 Bq L(-1) to 31.31 Bq L(-1) with 10.47 Bq L(-1) on average, and about 31.3% of the groundwater samples analyzed have a higher radon concentration than the maximum contaminant level of 11.1 Bq L(-1) recommended by United States Environmental Protection Agency (USEPA). The relatively high radon level in groundwater can be attributed to a relatively high uranium background produced by the magmatic activity and magmatic-hydrothermal system. The values of annual effective dose (AEDing) due to ingestion of radon in groundwater range from 0.002mSv y(-1) to 0.055mSv y(-1), 0.005mSv y(-1) to 0.11mSv y(-1) and 0.008mSv y(-1) to 0.188mSv y(-1) for adult, child and infant respectively. The values of annual effective dose due to the inhalation of radon released from water are 63.6, 15.4 and 3.8 times of those through the ingestion of radon in groundwater by the adults, children and infants, respectively. In addition, the values of estimated total annual effective doses are 0.020-0.480mSv y(-1), 0.017-0.406mSv y(-1) and 0.020-0.484mSv y(-1) for adult, child and infant, respectively. These values are much lower than the reference dose level of 1mSv y(-1) recommended by World Health Organization (WHO) and United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR).
作者机构：
[李春光; 谭凯旋] School of Nuclear Resources Engineering, University of South China, Hengyang, 421001, China;[夏良树] School of Nuclear Science and Technology, University of South China, Hengyang, 421001, China;[刘振中] School of Environmental Protection and Safety Engineering, University of South China, Hengyang, 421001, China
摘要：
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In order to study the fractal dynamic properties of uranium leach mining and discuss the influence of ore crushing on the dynamics of leach mining, uranium mine ore rocks in southern China were selected as the research object and an acid leaching experiment was performed on the ore samples with different fractal dimensions of 1.1, 1.4, 1.7, 2.0, 2.3 and 2.6. In the column leaching experiment, a PVC pipe with an inner diameter of 112 mm and a height of 1500 mm was used. The uranium content was determined by using titanium trioxide that was placed into a 0.1 mg ml
<jats:sup>−1</jats:sup>
standard uranium solution, and a sampling rate of once daily with a 5 ml volume of leaching solution was adopted after 8 h drenching time. The results show that the flow rate of the leaching solution depends on the distribution of the ore's particle size, that is, a larger fractal dimension results in a smaller flow rate. The concentration of the uranium leaching solution reaches a maximum value which subsequently decreases with time on the third day of the experiment, and it seems that the changes in the uranium concentration tend to be stable at around 15 days. Moreover, the concentration seems to increase with the increasing fractal dimension, and the fractal dimension of the ore particle size has a significant impact on the leaching kinetics. When the fractal dimension is between 1.1 and 2.6, the uranium dissolution rate,
<jats:italic>K</jats:italic>
, increases with the increasing fractal dimension. The kinetic reaction of the uranium leaching is a liquid–solid one, which is controlled by chemical reactions in the earlier phase. While the middle reaction phase is mainly chemical-diffusion reaction coupling, and the latter part of the reaction is controlled by diffusion. As the fractal dimension increases, the liquid–solid reaction controlled by diffusion appears at earlier phases. When the fractal dimension is greater than 2.0, the time of entering the diffusion control phase only changed little with the increasing of the fractal dimension. At last, a fractal dimension of 2.0 is suggested for the acid leaching of uranium ore crushing.
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摘要：
土壤氡浓度分布具有双分形特征,其分维值分别为 D 1=0.079 4和 D 2=1.465 4,分形临界值为2 167.7 Bq/m 3.低于临界值的分形其分维值 D 1很小,代表了区域背景分布,其背景值为1 088.16 Bq/m 3.高于临界值的分形其分维值 D 2显著增大,反映该区发生了较强的成矿作用的叠加.分形临界值可以作为异常下限值.金狮岭地区土壤氡浓度异常区分布范围较大,表明具有较好的成矿远景.
作者机构：
School of Nuclear Resources Engineering, University of South China, Hengyang, 421001, China;Guangxi;The Geophysical and Geochemical Institution of Hunan, Changsha, 410116, China
会议名称：
The 8th International Conference on Environmental and Engineering Geophysics (ICEEG 2018)(第八届环境与工程地球物理学国际会议)
会议时间：
2018-06-10
会议地点：
杭州
会议论文集名称：
The 8th International Conference on Environmental and Engineering Geophysics (ICEEG 2018)(第八届环境与工程地球物理学国际会议) 论文集
摘要：
In the data processing of uranium exploration, the key point is whether the lower limit of anomaly can be determined scientifically and efficiently.However, there are still some limitations in the traditional method, due to the complexity of the geological environment where the ore body is located.The research shows that the element background value and outlier value have independent exponential relationship, and the self-similarity exists between the part and the whole.So the lower limit of anomaly of the element can be obtained by the fractal method.With the γ-ray data of Jin Shiling uranium polymetallic deposit in Chenzhou, Hunan Province, the arcgis fractal method is used to determine the lower limit of anomalies and compared with the traditional method and the cumulative frequency method.The results show that the lower limit of anomalies calculated by fractal method is more in line with the known drilling data, indicating that the method can be effectively applied to extract γ spectrum information of uranium deposits under complex background conditions, which provides the basis for further exploration in the area.
作者机构：
[谭凯旋; 李春光; 谭婉玉] School of Nuclear Resources Engineering, University of South China, Hengyang, 421001, China;[刘振中] School of Environmental Protection and Safety Engineering, University of South China, Hengyang, 421001, China;[夏良树] School of Nuclear Science and Technology, University of South China, Hengyang, 421001, China
通讯机构：
School of Nuclear Resources Engineering, University of South China, Hengyang, China
作者机构：
[Xia, Liangshu; Li, Reirei; Xia, Yiqun; Zheng, Weina] School of Nuclear Science and Technology, University of South China, Hengyang;421001, China;Department of Radiochemistry, China Institute of Atomic Energy, P.O. Box 275-26, Beijing;102413, China;[Tans, Kaixuan] School of Nuclear Resource and Nuclear Fuel Engineering, University of South China, Hengyang
通讯机构：
[Xia, L.] S;School of Nuclear Science and Technology, China
作者机构：
[Xia, Yiqun; Zheng, Weina; Li, Reirei; Xia, Liangshu] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Xia, Yiqun] China Inst Atom Energy, Dept Radiochem, POB 275-26, Beijing 102413, Peoples R China.;[Tans, Kaixuan] Univ South China, Sch Nucl Resource & Nucl Fuel Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Xia, Liangshu] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
摘要：
Basic aspects of uranium adsorption by rice husk have been investigated. The influences of various experimental parameters such as pH, time, adsorbent dosage, rice husk size, temperature and various concentrations of uranium on uptake were evaluated. The thermodynamics and kinetics of adsorption were analyzed by FT-IR and SEM. The adsorption capacity for uranium on rice husk increased upon increasing initial concentration of uranium and temperature, while decreased with the increase of the amount of rice husk. Maximum uranium adsorption was observed at pH = 3 and particle size between 120 μm and 150 μm. Adsorption equilibrium was achieved within 60 min. At 25 °C, the saturated adsorption capacity qmax was up to 15.14 mg/g when the initial concentration of uranium ranged from 10 to 400 mg/dm<sup>3</sup>. The adsorption of uranium followed Langmuir adsorption isotherm and according to quasi-second order kinetic equation. The calculated values of δH<sup>o</sup>, δS<sup>0</sup>, and δG<sup>o</sup>indicated that the biosorption process was endothermic and spontaneous. Based on FT-IR spectra it may be concluded that hydroxyl, carbonyl, P-O and Si=O groups are the main active sites.<br/>
