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.
摘要：
新疆煤炭资源储量丰富,开采量巨大,然而某些煤矿含有较高放射性核素,对井下作业人员危害较大。为了掌握新疆井下工作人员的辐射照射状况,对新疆某地3家煤矿井下γ辐射剂量率、氡浓度、粉尘的放射性核素浓度进行监测与估算。结果表明A矿与B矿井下工作人员年有效剂量相对较高,分别为4.23 m Sv和1.90 m Sv;C矿相对较小,仅为0.57 m Sv,远低于全国平均水平。A矿超过了全国平均水平,主要由γ外照射引起,占到79.9%,可以通过缩短井下作业时间进行控制;B矿接近全国平均水平,主要来源于氡和氡子体内照射,占到总剂量的89.6%。可以通过隔离氡的析出和加强通风等方式降低受照剂量。
摘要：
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.
作者机构：
[Wangzhengqing; Liushan; Huyang; Xieyanshi; Duanxianzhe; Fengzhigang; Chenliang] Univ South China, Sch Nucl Resources Engn, Hengyang 421001, Hunan, Peoples R China.;[Huyang] Univ South China, Postdoctoral Res Stn Min Engn, Hengyang 421001, Hunan, Peoples R China.;[Huyang] Cooperat Innovat Ctr Nucl Fuel Cycle Technol & Eq, Hengyang 421001, Hunan, Peoples R China.;[Jiazhikun] Sinochem Petr Explorat & Prod Co Ltd, Beijing 100031, Peoples R China.
会议名称：
4th International Conference on Energy and Environmental Protection (ICEEP)
会议时间：
JUN 02-04, 2015
会议地点：
Shenzhen, PEOPLES R CHINA
会议主办单位：
[Huyang;Fengzhigang;Xieyanshi;Chenliang;Duanxianzhe;Wangzhengqing;Liushan] Univ South China, Sch Nucl Resources Engn, Hengyang 421001, Hunan, Peoples R China.^[Huyang] Univ South China, Postdoctoral Res Stn Min Engn, Hengyang 421001, Hunan, Peoples R China.^[Huyang] Cooperat Innovat Ctr Nucl Fuel Cycle Technol & Eq, Hengyang 421001, Hunan, Peoples R China.^[Jiazhikun] Sinochem Petr Explorat & Prod Co Ltd, Beijing 100031, Peoples R China.
关键词：
sandstone-type uranium deposit;chemical speciation of uranium;sequential chemical extraction;in-situ Leaching
摘要：
This paper presents a method of studying uranium speciation with six different hole depth and numbers from in-situ leaching sandstone-type uranium deposits by a sequential extraction procedure and demonstrates its application to sandstone uranium exploration. The chemical extraction procedure was modified from Tessier. The chemical speciation of uranium in samples was classified into six speciation: exchangeable ions, bound to carbonates, bound to sulfide-organic matter, bound to amorphous Fe-Mn oxides/bound to hydroxide, bound to sparry Fe-Mn oxides/bound to hydroxide and residual speciation. Studying the chemical speciation of uranium by method of sequential extraction show that the uranium distribution characteristics were significantly different whether they were in different samples or in the same sample. Therefore, a research on chemical speciation of Deposit behind the production is essential to reasonable evaluation of Deposit and guide the technology of in-situ leaching uranium Deposit. It also can rich the mineralization mechanism of sandstone-type uranium Deposit. The average amounts of bound to carbonates, exchangeable ions, bound to amorphous Fe-Mn oxides, residual speciation, bound to sulfide-organic matter and bound to sparry Fe-Mn oxides in order as 58.9%, 22.6%, 13.3%, 2.3%, 1.4% and 1.4%.
