共查询到16条相似文献,搜索用时 83 毫秒
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独联体国家的地浸采铀 总被引:1,自引:0,他引:1
独联体国家自60年代以来广泛开展了地浸采铀,浸出剂有酸和碱两种,但大多数矿山使用酸法浸出,过去的开采实践表明,这种采铀方法既经济、也有利于环境,本文讨论了地浸采铀与传统铀矿山生产相比的优缺点,并扼要地介绍了不同的地浸采矿方法。 相似文献
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主要介绍了地浸采铀的含义及其发展历史,并对地浸矿床的条件进行详细分析,提出地浸矿床评价的三项原则。 相似文献
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本文介绍了通过对可各市地浸砂岩铀矿开采阶段的成本构成和影响地浸法开采的各种参数的研究,找出关键参数的相互关系、确定其研究方法,以此建立数学模型,并用数学模型法进行经济技术评价。 相似文献
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地浸采铀是世界上十分先进的采矿技术,其基本原理是对可地浸砂岩型铀矿按一定网度布置工艺钻孔,从注液孔注入地浸液,使地浸液与铀进行充分反应,经抽液孔提出地表,在地表工厂进行萃取铀的过程.地浸法分为酸法和碱法两种.地浸采铀能使低品位砂岩型铀矿成为有工业价值的矿床,由于对环境污染小,已被世界大多数国家广泛采用.但是并非所有的砂岩铀矿都能地浸,只有符合地浸地质-水文评价指标的砂岩铀矿才能地浸.地浸工艺包括钻孔的布置、浸液的配制、地下水的复原和环境保护等方面.我国的地浸采铀于20世纪70年代开始探索,90年代中期开展了大规模的地浸砂岩铀找矿与开采工作,并取得了突破性进展,新疆512矿床是就是利用地浸技术评价与开采的我国第一座大型地浸铀矿山. 相似文献
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捷克采用新技术复原因遭地浸采铀而污染的地下水的工作取得进展。位于波西米亚地区北侧的斯特拉日地浸砂岩型铀矿是捷克、乃至东欧地区最大的采用原地浸出工艺开发的砂岩型铀矿,由于多种复杂原因,斯特拉日地浸砂岩型铀矿的地下水系统遭到污染。经过捷克境内外相关人士的通力合作,制定出了一份关于复原斯特拉日地浸砂岩型铀矿遭污染地下水系统的方案,需治理地域的面积达27km^2,约需资金62亿美元,地下水复原需要的时间为100a(指地下水中的各种元素含量水平恢复到原先未采铀时的水平)。 相似文献
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砂岩型铀矿床地浸地质工艺性能综合定量评价指标--地浸指数的设计与应用 总被引:3,自引:2,他引:3
从砂岩型铀矿床地浸开发工艺着手,通过对其地质影响因素分析,结合各因素对地浸开发的影响程度,提出了砂岩型铀矿床地浸的地质工艺性能综合评价指标——地浸指数(LI),并建立了其计算模型。通过计算地浸指数可定量地了解待开发矿床或块段的地浸开发适宜程度。地浸指数LI值越大,说明该矿床地浸的地质工艺性能越佳、越有利于地浸开发。通过对伊犁盆地512模型铀矿床、511铀矿床及吐哈盆地十红滩铀矿床的LI值试算,得到的LI值分别为119.95、102.56和47.8l。试算结果表明,511矿床很有利于地浸开发,511矿床地浸开发的有利性逊于512矿床,十红滩矿床属于不利于地浸的范畴,建议放弃酸法地浸方案,寻求低酸法地浸、清水地浸或减法地浸等方案。结合3个矿床的工业开发实际和前期试验成果,初步确定砂岩型铀矿床地浸地质工艺性能的LI值区间:LI≥100,很有利于地浸;80≤LI<100,有利于地浸:LI<80,不利于地浸。 相似文献
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Qingliang WANG 《中国地球化学学报》2006,25(B08):180-180
Synthetic surfactants are among the most widely used chemicals in the world (around 10 millions of tons are produced per year), mainly as key components in detergent formulation, apart from other applications such as wetting agents or emulsifiers. Coastal ecosystems receive large quantities of these compounds and, after a relatively fast partial degradation in water, the remaining quantities end up in the sediments due to their high affinity for organic carbon in the particulate phase. We therefore focused our studies on sediments because they can be assumed to play an important environmental role acting as a sink for these contaminants. Moreover, because of their widespread use and source specificity, surfactants can usefully be employed as molecular indicators in sediments for more general contamination caused by human activities. This work deals with the vertical distribution in sediment cores of the main anionic surfactants, both linear alkylbenzene sulfonates (LAS) and alkyl ethoxysulfates (AES), and non-ionic surfactants, including nonylphenol polyethoxylates (NPEOs) and alcohol polyethoxylates (AEOs). In the case of LAS their degradation metabolites sulfophenyl carboxylic acids (SPCs) are also studied. The processes considered are degradation, sorption and diffusion occurring along the sedimentary column for the different homologues contained in the commercial surfactant mixtures. The most hydrophobic surfactants such as NPEOs and AEOs remain strongly attached to the particulate phase whereas polar metabolites such SPCs tend to be present in the pore water. Highest values of surfactants are found near the surface and, in most cases, there is a decrease in their concentration down the sediment core. Furthermore, the reduction in the average length of the ethoxylated chain in polyethoxylated surfactants, as well as the increase in the concentrations of SPCs at depths showing redox potential from -300 to -400 mV, suggests that surfactants may be degraded anaerobically in the sediment. In the case of LAS, these field results are compared with the data from laboratory experiments carried out in order to determine sorption capacity and anaerobic degradation. 相似文献
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Factors influencing in-situ leaching of uranium mining in a sandstone deposit in Shihongtan,Northwest China 下载免费PDF全文
The Shihongtan uranium deposit in northwest China is a sandstone-type deposit suitable for alkaline in-situ leaching exploitation of uranium. Alkaline leaching tends to result in CaCO3 precipitation there by affecting the porosity of the ore-bearing aquifer. CaCO3 deposits can also block pumping and injection holes if the formulation parameters of the leaching solution are not well controlled. However, controlling these parameters to operate the in-situ leaching process is challenging. Our study demonstrates that the dissolved uranium concentration in the leaching solution increases as HCO3- concentration increases. Therefore, the most suitable HCO3- concentration to use as leaching solution is defined by the boundary value of the HCO3- concentration that controls CaCO3 dissolution-precipitation. That is, the dissolution and precipitation of calcite is closely related to pH, Ca2+ and HCO3- concentration. The pH and Ca2+ concentration are the main factors limiting HCO3- concentration in the leaching solution. The higher the pH and Ca2+ concentration, the lower the boundary value of HCO3- concentration, and therefore the more unfavorable to in-situ leaching of uranium. 相似文献
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