Heavy minerals

重矿物
  • 文章类型: Journal Article
    现代科学在重矿物应用方面的最新进展,工程,几十年来,技术和冶金工业特别是核能和电力工业的需求显着增加。这是重矿物产品的关键性和商业化的原因,也需要工业对其的高需求。重质矿物的回收,例如:来自其矿床的Zr和Ti伴生矿物依赖于来自复杂矿物的过渡金属和难熔金属的提取冶金。根据矿物浓缩和金属提取的有效性和效率,在他们的恢复过程中遇到了一些挑战,特别是在它们与相关的矿物杂质或脉石的分离中。然而,这篇综述的重点是研究磁性和静电物理处理技术及其在重矿物选矿和回收中的应用。因此,这将是,作为减少工艺步骤和提取复杂性的工具,涉及到溶解和湿法冶金过程的下游措施的矿物。
    Recent advancements in the applications of heavy minerals by modern science, engineering, technological and metallurgical industries especially in the demand by nuclear and power industries have significantly increased over the decades. This is the reason for the criticality and commerciality of products of heavy minerals and also necessitated their high demand by industries. The recovery of heavy minerals, such as: Zr and Ti associated minerals from their deposits is dependent on extractive metallurgy of transition and refractory metals from complex minerals. Based on the effectiveness and efficiency of mineral concentration as well as metal extraction, several challenges have been encountered in their recovery process, especially in their separation from associated mineral impurities or gangue. This review is however focused on investigating magnetic and electrostatic physical processing techniques and their applications in the beneficiation and recovery of heavy minerals. This will therefore, serve as a tool in reducing process steps and extraction complexity involved in downstream measures of dissolution and hydrometallurgical processes of the minerals.
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  • 文章类型: Journal Article
    确定原始碎屑组合中重矿物的相对丰度是否以及在多大程度上通过机械运输进行了修改,这有助于了解区域历史气候变化和获取现代沉积物物源信息。利用重矿物的表面机械光学纹理的频率可能是解决此问题的有效方法。然而,重矿物的频率表面机械光学纹理与这些矿物的相对丰度变化之间的联系仍然不确定。在这项研究中,从中国西北高干旱地区的巴丹吉林沙漠收集了12个现代风沙样品,以弱风化为特征,分析了五种主要重矿物的相对含量。然后,在偏光显微镜的平行光下拍摄了3796个透明重矿物颗粒,并计算了13个表面机械光学织构的频率。结果表明,重矿物相对丰度的变化受机械运输的影响很大。机械稳定性弱的重矿物相对丰度的减少主要归因于机械碰撞。相反,机械稳定性强的重矿物的相对丰度变化主要受机械磨损的影响。因此,机械输运对弱化学风化地区重矿物相对丰度的影响。使用机械上不稳定的矿物的相对丰度建立用于物源研究的重矿物特征指数可能不能直接指示运输距离,而是风力的强度。在古风状态研究中具有巨大潜力。这项研究扩展了沉积物表面微观形态的研究领域,并在推断过去的气候变化和确定现代沉积物来源方面具有潜在的应用。
    Determining whether and to what extent the relative abundance of heavy minerals in original detrital assemblage has been modified by mechanical transport is beneficial for understanding regional historical climate changes and acquiring modern sediment provenance information. Utilizing the frequency of surface mechanical optical textures of heavy minerals may be an effective approach to address this question. However, the connection between the frequency surface mechanical optical textures of heavy minerals and the variations in the relative abundance of these minerals remains uncertain. In this study, 12 modern aeolian sand samples were collected from the Badain Jaran Desert in hyper arid region of northwestern China, characterized by weak weathering to analyze their relative contents of five major heavy minerals. Then, 3796 transparent heavy mineral grains were photographed under the parallel light of a polarizing microscope, and the frequency of 13 surface mechanical optical textures were calculated. The results reveal that the variations in the relative abundance of heavy minerals are substantially influenced by mechanical transport. The decrease in the relative abundance of heavy minerals with weak mechanical stability primarily attributed to mechanical collision. Conversely, the variations in the relative abundance of heavy minerals with strong mechanical stability are primarily influenced by mechanical abrasion. Therefore, mechanical transport impact on the relative abundance of heavy minerals in regions with weak chemical weathering. Establishing heavy mineral characteristic indices for provenance studies using the relative abundance of mechanically unstable minerals may not directly indicate transport distance but rather the strength of wind forces, which have significant potential in palaeo wind regime studies. This study expands the research field of sediment surface micromorphology and has potential applications in inferring past climate changes and determining modern sediment provenance.
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  • 文章类型: Journal Article
    格雷戈里憩室,一种独特的消化道结构,是一组衍生的沙元(Echinoidea:Scutelliformes),充满了从动物栖息的基质中获得的沙粒。通过样品照射强光或测试对磁铁的反应的简单方法可以揭示矿物填充憩室的存在。比重>2.9g/cm3的重矿物质被选择性地浓缩在器官内部,通常浓度为一个数量级,或更多,大于在底物中发现的。9属13种憩室含量分析,使用光学矿物学,粉末X射线衍射,扫描电子显微镜和能量色散X射线光谱,以及显微计算机断层扫描显示了对五种主要重矿物的选择的偏好:磁铁矿(Fe3O4),赤铁矿(Fe2O3),钛铁矿(FeTiO3),金红石(TiO2),和锆石(ZrSiO4)。少量的重质或微重闪石,辉石和石榴石矿物颗粒也可以掺入。总的来说,动物对比重>4.0g/cm3的矿物颗粒表现出偏好,尽管选择是机会性的,矿物物种的实际混合取决于基质的矿物组成。动物还选择粒度,矿物颗粒通常在50至150μm的范围内,并且在个体发育过程中似乎不会改变这种偏好。分析方法的比较表明,当从标本或与标本一起收集的基质中破坏性提取的矿物颗粒的相关分析支持时,使用微型计算机断层扫描测量的X射线衰减是用于重矿物定量的可靠的非破坏性方法。摄入矿物的电化学表面性质的共性表明,这些特征在选择过程中起着重要作用。
    Gregory\'s diverticulum, a digestive tract structure unique to a derived group of sand dollars (Echinoidea: Scutelliformes), is filled with sand grains obtained from the substrate the animals inhabit. The simple methods of shining a bright light through a specimen or testing response to a magnet can reveal the presence of a mineral-filled diverticulum. Heavy minerals with a specific gravity of >2.9 g/cm3 are selectively concentrated inside the organ, usually at concentrations one order of magnitude, or more, greater than found in the substrate. Analyses of diverticulum content for thirteen species from nine genera, using optical mineralogy, powder X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy, as well as micro-computed tomography shows the preference for selection of five major heavy minerals: magnetite (Fe3O4), hematite (Fe2O3), ilmenite (FeTiO3), rutile (TiO2), and zircon (ZrSiO4). Minor amounts of heavy or marginally heavy amphibole, pyroxene and garnet mineral grains may also be incorporated. In general, the animals exhibit a preference for mineral grains with a specific gravity of >4.0 g/cm3, although the choice is opportunistic and the actual mix of mineral species depends on the mineral composition of the substrate. The animals also select for grain size, with mineral grains generally in the range of 50 to 150 μm, and do not appear to alter this preference during ontogeny. A comparison of analytical methods demonstrates that X-ray attenuation measured using micro-computed tomography is a reliable non-destructive method for heavy mineral quantification when supported by associated analyses of mineral grains extracted destructively from specimens or from substrate collected together with the specimens. Commonalities in the electro-chemical surface properties of the ingested minerals suggest that such characteristics play an important role in the selection process.
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  • 文章类型: Journal Article
    这项研究的目的是通过检查其地形来评估WadiElGemal岛的自然资源和放射性风险,矿物学,地球化学,和放射性分布。这个岛,位于埃及东南沙漠WadiElGemal的出口,具有独特的形状,类似于基于Landsat图像的海豚。它是WadiElGemal-Hamata保护区的一部分,以其多样化的环境而著称,地质,经济,和考古特征,包括最近的珊瑚礁,沙质沉积物,第四纪碳酸盐沉积物,还有红树林.岛上的主要自然资源是动物,红树林,还有Flora.从岛上收集的样品使用NaI检测器进行分析,以测量放射性核素的浓度,例如238U,232Th,226Ra,40K,根据UNSCAR指南,被发现在可接受的水平内。放射性核素238U,232Th,226Ra,采集样品的40K活性浓度分别为32.55±9、12.63±4、12.49±4和325±34Bq/kg,分别。关于放射性危害指数,吸收γ剂量率值(36.06±5.42nGy/h),镭当量活度(73.88±14.4Bq/kg),室内(0.18±0.03mSv/y)和室外(0.04±0.01mSv/y)的年有效剂量,内部(0.29±0.05)和外部(0.2±0.03)指数,和超额终生癌症指数(0.15±0.05×10-3)。这表明与这些沉积物没有重大风险。
    The objective of this study is to assess the natural resources and radiological risks of Wadi El Gemal Island by examining its topography, mineralogy, geochemistry, and radioactive distributions. This island, which is situated at the outlet of Wadi El Gemal in Egypt\'s southeastern Desert, has a unique shape resembling a dolphin based on Landsat imagery. It\'s a part of the Wadi El Gemal-Hamata Protectorate and is notable for its diverse environmental, geological, economic, and archeological features, including recent reefs, sandy deposits, Quaternary carbonate sediments, and mangroves. The main natural resources on the island are fauna, mangrove forests, and flora. Samples collected from the island were analyzed using a NaI detector to measure the concentrations of radionuclides such as 238U, 232Th, 226Ra, and 40K, which were found to be within acceptable levels according to UNSCAR guidelines. The radionuclide 238U, 232Th, 226Ra, and 40K activity concentrations of the collected samples were 32.55 ± 9, 12.63 ± 4, 12.49 ± 4, and 325 ± 34 Bq/kg, respectively. Regarding radiological hazard indices, the values of absorbed gamma dose rate (36.06 ± 5.42 nGy/h), radium equivalent activity (73.88 ± 14.4 Bq/kg), annual effective dose indoor (0.18 ± 0.03 mSv/y) and outdoor (0.04 ± 0.01 mSv/y), internal (0.29 ± 0.05) and external (0.2 ± 0.03) indices, and excess lifetime cancer index (0.15 ± 0.05 × 10-3).This is suggest that there is no significant risk associated with these sediments.
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  • 文章类型: Journal Article
    砂岩成分受多种因素影响,包括酸性风化,发生在内陆地区储存期间,在沉积之前。这项研究旨在更好地理解和限制这种沉积前因素的性质和持续时间如何影响最终的沉积物组成。来自克莱尔盆地的中石炭纪三角洲砂岩,爱尔兰西部,沉积环境和来源受到很好的限制,是本研究的目标。常规重矿物分析和特定重矿物比率,例如磷灰石-电气石指数用于检查这些现象。在沟渠化砂岩中观察到的磷灰石-电气石指数值相对较高,而在与口杆和分流海湾相相关的砂岩中观察到的较低值。这些变化与来源的变化无关,因此可能表明由于冲积物储存的持续时间不同,风化强度存在差异。这些变化可能与在沟渠中的腹地停留时间比在口栏和分流间海湾砂岩中短有关。在金红石-锆石指数中可以看到变化,与相没有任何明显的联系。这些波动可能归因于来源的可变供应,金红石含量相对丰富,但锆石和磷灰石含量较差。尽管这些砂岩中的磷灰石成分部分来自回收来源,磷灰石-电气石指数剧照似乎掌握了最后一个沉积周期的信息。
    Sandstone composition is influenced by multiple factors, including acidic weathering, occurring during storage in the hinterland, prior to deposition. This study aims to better understand and constrain how the nature and duration of such pre-depositional factors might impact the final sediment composition. Mid-Carboniferous deltaic sandstones from the Clare Basin, western Ireland, for which depositional environments and provenance are well constrained, are the target of this study. Conventional heavy mineral analysis and specific heavy mineral ratios, such as the apatite-tourmaline index are utilised to examine these phenomena. Relatively high apatite-tourmaline index values observed in channelised sandstones contrast with lower values seen in sandstones associated with mouth bar and interdistributary bay facies. These variations are not linked to changes in provenance and thus potentially indicate differences in weathering intensity due to variable duration of alluvial storage. These changes are probably linked with shorter hinterland residence time in the channelised than in mouth bar and interdistributary bay sandstones. Variations are seen in the rutile-zircon index without any clear link with facies. These fluctuations could be ascribed to variable supply from a source, which is relatively rich in rutile but poor in zircon and apatite. Despite the apatite component in these sandstones being partially derived from recycled sources, the apatite-tourmaline index stills appears to hold information on the last sedimentary cycle.
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