Use of portable X-ray fluorescence in the analysis of surficial sediments in the exploration of hydrothermal vents on the Southwest Indian Ridge

Hydrothermal plumes released from the eruption of sea floor hydrothermal fluids contain large amounts of oreforming materials. They precipitate within certain distances from the hydrothermal vent. Six surficial sediment samples from the Southwest Indian Ridge（SWIR） were analyzed by a portable X-ray fluorescence（PXRF） analyzer on board to find a favorable method fast and efficient enough for sea floor sulfide sediment geochemical exploration. These sediments were sampled near, at a moderate distance from, or far away from hydrothermal vents. The results demonstrate that the PXRF is effective in determining the enrichment characteristics of the oreforming elements in the calcareous sediments from the mid-ocean ridge. Sediment samples（〉40 mesh） have high levels of elemental copper, zinc, iron, and manganese, and levels of these elements in sediments finer than 40 mesh are lower and relatively stable. This may be due to relatively high levels of basalt debris/glass in the coarse sediments, which are consistent with the results obtained by microscopic observation. The results also show clear zoning of elements copper, zinc, arsenic, iron, and manganese in the surficial sediments around the hydrothermal vent. Sediments near the vent show relatively high content of the ore-forming elements and either high ratios of copper to iron content and zinc to iron content or high ratios of copper to manganese content and zinc to manganese content. These findings show that the content of the ore-forming elements in the sediments around hydrothermal vents are mainly influenced by the distance of sediments to the vent, rather than grain size. In this way, the PXRF analysis of surface sediment geochemistry is found to satisfy the requirements of recognition geochemical anomaly in mid-ocean ridge sediments. Sediments with diameters finer than 40 mesh should be used as analytical samples in the geochemical exploration for hydrothermal vents on mid-oceanic ridges. The results concerning copper, zinc, arsenic, iron, and manganese and their ratio features can be used as indicators in sediment geochemical exploration of seafloor sulfides.

Application of a Portable XRF Spectrometer for <i>In-Situ</i>and Nondestructive Investigation of Pigments in Two 15th Century Icons

A simple portable X-Ray Fluorescence (XRF) spectrometer was successfully used for in-situ and nondestructive identification of the painting materials in two 15th century icons from the Onufri Museum in Beart, Albania. The spectrometer is based on a low power X-ray tube, a thermoelectrically cooled Si PIN detector and the spectrum acquisition system. It was assembled and adjusted at our laboratory for the investigation of the icons. A small number of pigments were clearly identified by X-Ray Fluorescence (XRF) measurements in both icons. This includes Lead white for the white color, gold and yellow ochre for the yellow color, red lead, cinnabar and red ochre for the red color, as well as cooper based pigments for the green color. At the same time, the investigation raised some new questions that need further investigations by the use of additional analytical techniques. The results show that in both icons are used similar pigments, which are in accordance with the Byzantine icon painting tradition.

A TOTAL CONTENT X—RAY FLUORESCENCE METHOD FOR COPPER PROSPECTING

A new method is proposed to prospect copper deposits with portable XRF analyzer. The method is based on the close relation between Cu and the chalcophile elements or some other elements in the geochemical anomalies of a Cu deposit. Applications of the technique in Northeast China are presented.

Quantification of Silicon (SI) and Silicon Dioxide (SiO2) from the Nafud Desert-Al-Qassim Region, Kingdom of Saudi Arabia Using XRD Analysis

This research was conducted in the Qassim region, Kingdom of Saudi Arabia. The goal of this research is to determine the percentage of silicon in the Rub al-Khali desert. Samples were collected from four cities located in the Al-Qassim Region of Saudi Arabia (Uyun Al-Jawa, Al-Fuwailiq, Al-Sulaibiya, and Al-Qawara), from three distinct depths (the earth’s surface, 50 cm, and 100 cm). The percentages of silicon in these places vary between the highest value for silicon dioxide, which is 74.47 m/m%, and 34.8 m/m% for silicon in Al-Qawara city at a depth of 100 cm. We used an x-ray fluorescence (XRF) instrument to evaluate the samples. There are high percentage of both silica and silicon in the Nafud desert. Studies have shown that these ratios can help investors benefit from an element of Silicon and silicon dioxide, so the sands of the Nafud desert is sufficient for extracting Silicon and silica in huge quantities. This may transform the Kingdom into a leading country in the global computer technology industry that depends on silicon extracted from the desert sands, the most important of which are microcomputer data processing devices.

XRF和PXRF测定土壤中10种重金属元素方法研究

本文采用台式X射线荧光光谱仪(台式XRF)和便携式X射线荧光分析仪(PXRF)分别对土壤中Cu、Cr、Pb、Zn、Ni、As、Co、V、Mn和Ti等10种元素进行监测分析。采用台式XRF分析这10种元素在各自相应的范围内线性良好,r=0.9990~0.9999,检出限为0.8 mg/kg~5.5 mg/kg,平行测定3次的RSD<2%;而采用PXRF测定,RSD<10%,准确度明显低于台式XRF,对土壤中Cr、Zn、Ni、As、Co、V和Mn等部分元素仅可进行半定量分析。X射线荧光光谱法简化了土壤样品分析,解决了传统的检测分析方法,耗时长,前处理复杂,强酸的使用易导致环境的二次污染等问题,在土壤重金属分析中具有明显的优势。

新一代高灵敏度手提式X荧光仪的研制

介绍了新一代高灵敏度手提式X射线荧光仪 ,该仪器由电制冷Si PIN半导体X射线探测器、放射性同位素X射线激发源和基于PC/ 10 4工控机的 4 0 96道多道脉冲幅度分析器组成 ,对铜、锌、砷等元素的分析检出限为 10× 10 -6,适用于野外现场的天然岩石、土壤和水系沉积物的多元素含量的定量测定 ,基本满足新一轮地质大调查的需要 ,特别是二、三级异常点 (带 )的快速查证与野外追索工作。

便携式X荧光分析仪在萤石矿勘查中的应用

在赤峰市林西县水头萤石矿区,利用便携式X荧光分析仪对第四系浅覆盖区进行隐伏萤石矿体探测的有效性试验。通过测量数据分析及与已知矿体的对比证明,在浅覆盖区利用X荧光分析仪勘查隐伏萤石体是有效的。该结论为便携式X荧光仪在勘查隐伏萤石矿体中的应用提供了重要依据。

便携式能量色散X荧光分析仪的研制

本文介绍了一种新型便携式能量色散 X荧光分析仪的工作原理与硬件结构。该仪器可在野外现场进行多元素快速、无损分析。仪器的准确度。

西天山某航磁异常点查证中现场X荧光分析技术的应用

现场X荧光分析技术是一种轻便、快速、高效、低投入的野外勘查技术。在航磁异常查证中应用现场X荧光分析技术,对新疆西天山某航磁异常点岩石与土壤中的Fe、Cu、Zn、Pb、As、Mn、Ni元素进行了分析,获得了该地区上述元素的分布,为航磁异常评价提供了依据。实践证明,现场X荧光技术为航磁异常查证提供了快速便捷的手段。

X荧光现场取样技术在大红山铜矿的应用

介绍了利用自行研制的便携式X射线荧光分析仪在大红山铜矿井下用X荧光取样分析代替人工打点取样分析 ,现场原位测量岩壁Cu、Fe品位的应用情况。采用的仪器是由2 3 8Pu同位素源、正比计数管、多道脉冲幅度分析器、便携微机系统等组成的能量色散型分析仪 ,具有自动稳谱功能。研究结果表明 :X荧光取样的原矿品位与化学分析结果相比 ,Cu相对误差在 10 %以内的合格率达到 95 % ,Fe相对误差在 5 %以内的合格率为 90 % 。

用总量X荧光法勘查铜矿

本文以各类铜矿床的地球化学异常中的元素组合为依据,研究了用国产携带式X荧光仪勘查不同类型铜矿床的方法与技术,并介绍了在东北某铜矿区用本文所述方法技术勘查铜矿的试验效果。

轻便型X荧光仪多道脉冲幅度分析器的研制

本文详细介绍了一种用于现场辐射测量的多道脉冲幅度分析器，多道分析器的道数为２０４８道，适合半导体探测器等具有高分辨能力的探测器使用，电路设计中选用了功耗较低的元器件，仪器适合野外使用。

便携式X荧光仪关键技术研究

针对现行便携式Ｘ荧光仪灵敏度低、检出限差、测定元素少、基体效应校正能力弱等问题，对激发源、探测与测量系统、微机化等关键技术进行了研究。研制了微型低功率Ｘ光管激发源、低功耗１０２４道分析器，实现了以笔记本式微型计算机系统为核心的微机化，构成了高灵敏度便携式Ｘ荧光仪。它可测定多种元素，较轻和中等原子序数元素的检出限达到几至十几μｇ／ｇ，比现行便携式Ｘ荧光仪改善１个量级以上，基体效应校正和数据处理功能大为增强。

便携式X射线荧光仪用于铁矿石品位快速测定

论述了便携式Ｘ射线荧光仪用于铁矿石品位快速测定的基本原理和关键技术。在朱家包包铁矿的生产试验表明：实时测定的原矿品位与常规的化学分析相比，绝对误差在１５％内的合格率为９４１％，在０５％内为４５９％。

一种便携式荧光测油仪在海上溢油应急监测中的适用性研究

研究了一种便携式荧光测油仪在海上溢油应急监测中的适用性,并与现行仲裁标准方法进行比较分析。研究表明:该便携式荧光测油仪测定海水中油类样品仅需100 mL水样,平均每个样品所需的前处理时间约340 s,方法检出限为0.003 mg/L,测定下限为0.012 mg/L。测定用标准物质配制的不同浓度海水样品,相对标准偏差为0.08%~0.87%,测定标准样品的相对误差为0.49%~4.50%,实际样品加标回收率为90%~107%。对标准物质配制的海水样品进行检测,与现行仲裁标准方法在0.05水平下无显著性差异。在渤海中部海上监测中,连续6 d测定不同标准样品的相对标准偏差为0.26%~0.83%。研究结果表明,该便携式荧光测油仪适用于现场对油类的定量分析和水质评价。

A New Discovery of Ag-Pb-Zn Mineralization via Modern Portable Analytical Technology and Stream Sediment Data Processing Methods in Dajiacuo Area, Western Tibet(China)

Tibet, which is rich in mineral resources, is a treasure trove for geological explorers. However, prospecting work has been slow, especially in the western part, due to the precipitous terrain, changeable climate and low access. Hence, modern advanced field analytical technology and effective data processing methods play significant roles in rapid and efficient exploration in Tibet. In this paper, spectrum-area fractal modeling and portable X-ray fluorescence analysis(pXRFA) were used to identify and verify geochemical anomalies associated with Ag-Pb-Zn mineralization based on a stream-sediment dataset of 39 elements in the Dajiacuo-Xurucuo region of western Tibet. First, staged factor analysis(SFA) was used to obtain the Ag-Pb-Zn-Cd geochemical assemblage. Second, the first-factor pattern obtained using SFA was dissociated by a spectrum-area(S-A) fractal model and a digital elevation model(DEM)-based geochemical model(DGM) was constructed. Finally, the sections of Ag, Cd, Pb, and Zn were obtained using pXRFA. The results show that Ag-Pb-Zn-Cd enrichment zones were mostly located around the contact belt of volcanic rocks and intrusions, or along SE-NW trending faults. Considering the variable terrain and catchment basin, the extension of long axes of Ag-Pb-Zn-Cd anomalies into higher elevation areas that are favorable for Ag-Pb-Zn mineralization should be investigated. Anomaly maps created with the aid of a DGM show promising potential for mineralization in the Dajiacuo-Xurucuo region, and abundant Ag-Pb-Zn mineralization was identified with the assistance of pXRFA in the source areas for the geochemical anomalies in the Dajiacuo. We conclude that SFA and the S-A fractal model constitute a valid tool to identify or verify geochemical anomalies in areas of low-density stream-sediment sampling. The pXRFA can accurately determine the source of geochemical anomalies and improve anomaly verification efficiency.

Rapid Growth of Pentaerythritol Crystal

Pentaerythritol（PET） crystal has been grown rapidly from the solution with sulfuric acid as the additive. The growth rate of PET crystal in prismatic shape exceeds 1.5 mm/day and crystallization size is 55×55×50 mm^3. X-ray diffraction analysis was used to confirm the structure integrity. The diffraction efficiency of rapid-grown crystal was characterized as effective as that of normal growth.

冷原子荧光便携式痕量汞水质在线监测仪与实验室汞分析仪比较研究

本研究对冷原子荧光便携式痕量汞水质在线监测仪与两种实验室汞测定仪器进行了检出限、测定上限、准确度、精密度、离子干扰、实际水样加标回收率等指标的比较。这两种实验室汞分析仪是DMA-80痕量汞分析仪和AFS-230E双道原子荧光光度计。实验证明,集前处理于一体的冷原子荧光便携式痕量汞水质在线监测仪,性能上分析灵敏度高,准确度、精密度和抗离子干扰能力与两种实验室仪器无明显差异,能满足地表水汞在线监测的要求。

便携式X荧光分析仪快速测定土壤中Cd·Hg·As·Pb·Cr含量

[目的]探索便携式X荧光分析仪应用于环境应急监测中的可行性。[方法]采用X荧光分析法选择《土壤环境质量标准》（GB15618—1995）中重点监测的Cd、Hg、As、Pb、Cr进行标准样品分析,进行现场实测与实验室样品分析,研究该方法测定这5种重金属的准确度和精密度。[结果]X荧光分析法测定土壤标准物质的相对标准偏差（RSD）为1.77%-22.90%。现场样品实测相对偏差（RD）为-42.00%-18.10%,其中Cr的RD较小,为-21.20%-10.50%;As的RD较大,为-42.00%-18.10%。[结论]便携式X荧光分析仪在土壤重金属环境应急监测中具有一定指导作用。

手持式X射线元素检测仪在土壤重金属检测中的应用

通过采用手持式X射线元素检测仪X荧光法与国标方法对土壤样品进行了测试比对,对土壤中的Pb、Cu、Zn、As、Ni等重金属进行了检测。试验结果表明:手持式X射线元素检测仪能够用于土壤中的Pb、Cu重金属定性定量检测和土壤中Zn、As重金属进行定性半定量检测,不能满足土壤中Ni的检测应用。