本文關鍵詞：化學前處理—能量色散X射線熒光光譜法應用于礦石及水體現(xiàn)場分析，由筆耕文化傳播整理發(fā)布。

        能量色散-X射線熒光光譜法(EDXRF)在礦產勘查、礦山環(huán)境監(jiān)測及找礦現(xiàn)場分析中具有重要地位。包括硫化物礦石在內的高礦化度地質樣品,由于缺乏基體匹配的標準樣品,存在分析校準問題,基體校正難度也很大,分析數(shù)據的準確度會受到嚴重影響,制約了EDXRF在該類樣品分析中的應用；分散在水體中的、對生態(tài)環(huán)境和人類健康危害較大的重金屬元素,由于其元素濃度一般低于EDXRF儀器檢出限而無法檢出。為了滿足礦產勘查現(xiàn)場對高礦化度及礦石樣品準確、可靠分析的需要,以及水體中重金屬濃度現(xiàn)場監(jiān)測分析的需求,急需開發(fā)與分析對象相配套的EDXRF制樣、分析方法。本文針對富含硫化物礦物的高礦化度樣品及礦石樣品,采用了酸消解的溶液制樣方法；針對水樣中較低濃度重金屬采用了離子交換紙動態(tài)富集制樣方法,結合EDXRF技術,建立了硫化物礦石和多金屬礦石中銅、鉛、鋅元素分析方法各一套；研制了適合水樣中銅、鉛、鋅、鎳等元素富集制樣的離子交換紙及動態(tài)富集裝置,開展了交換富集試驗。具體實驗方案與實驗結論如下：(1)硝酸+氫氟酸封閉消解試樣,絡合緩沖溶液定容、進樣,標準溶液校準-偏振能量色散-X射線熒光光譜(PE-EDXRF)同時測定硫化物礦石樣品中銅、鉛、鋅三種元素。確定了消解與測量方法,用GBW07162～GBW07168七種礦石國家一級標準物質對該方法進行了驗證。結果表明,當樣品中Cu、Zn、Pb元素含量大于1%時,幾乎所有樣品中的銅、鉛、鋅元素的精密度值(RSD, n=6)優(yōu)于5%,檢測結果與標準值一致性良好。該方法是對EDXRF測量進樣方式的一種探索,是對實驗室礦石分析技術的擴充,也為現(xiàn)場礦石分析奠定了基礎。(2)在祁曼塔格多金屬礦區(qū)現(xiàn)場試驗了“水浴加熱+王水在比色管中消解樣品”及“電熱板加熱+鹽酸、硝酸順序消解+硝酸提取”兩種樣品處理方式,使用專門研制的具有雙層薄膜結構的液體樣品盒,標準溶液進行校準,PE-EDXRF同時測定了銅、鉛、鋅三種元素。對這兩種酸消解方法制備的樣品進行分析時,均采用二級靶Mo Kα譜線的康普頓散射峰作為內標校正基體效應。采用現(xiàn)場電熱板加熱方式,分析二件礦區(qū)樣品的方法精密度(RSD,n=10)均優(yōu)于2%,分析四件管理樣獲得的分析相對誤差均優(yōu)于5%(當含量>0.5%時),十三件礦區(qū)未知樣品PE-EDXRF與原子吸收分光光度法(AAS)平均相對偏差分別為2.87%、2.82%、6.84%。在高海拔地區(qū)(海拔大于4000米)使用“水浴加熱+王水在比色管中消解樣品”法存在分析結果系統(tǒng)偏低問題,但實驗數(shù)據用地質管理樣進行修正后,可以得到滿意的結果。試驗證明,采用研制的雙層膜液體樣品盒,可以直接測定強酸性液體樣品,不會產生泄漏、揮發(fā)等造成的儀器損壞。用兩種現(xiàn)場樣品酸消解技術所建立的PE-EDXRF分析方法,克服了基體匹配標樣缺乏的問題,解決了高礦化度樣品及礦石樣品的現(xiàn)場較高精度分析問題,是對粉末制樣法PE-EDXRF現(xiàn)場分析技術的一個補充和改善,豐富了車載EDXRF技術的現(xiàn)場分析能力。(3)研制了具有富集水體樣品中銅、鉛、鋅、鎳等重金屬元素能力的離子交換特種紙片,經交換富集后的紙片可直接用于EDXRF測量。研制了具有動態(tài)交換富集功能的交換富集裝置。對混合標準溶液和單元素標準溶液進行的富集實驗表明,銅、鋅、鎳的檢出限達到幾個ng/mL,鉛的檢出限達到約20ng/mL,為EDXRF應用于現(xiàn)場水體重金屬監(jiān)測奠定了基礎。本研究形成的成果包括已被《巖礦測試》(核心期刊)接受的研究論文2篇,已被國家知識產權局批準(公示中)的實用新型專利3項。通過本研究,使車載EDXRF技術對勘查找礦和環(huán)境監(jiān)測工作現(xiàn)場分析支撐能力獲得提升。

    Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF) is a popular on-site analytical technique in mineral prospecting, mine environment monitoring. Lack of sufficient matrix matching calibration samples has been a major problem affecting the accuracy and reliability of on-site EDXRF analysis for highly mineralized samples and metal ores including sulfides. Moreover, the relatively low sensitivity of portable or transportable EDXRF spectrometers prohibit their direct use in on-site monitoring of heavy metals in surface and underground water samples in which the concentrations of heavy metals are far below the detection limits of the technique. Meanwhile, laboratory wet chemical analysis techniques and many preconcentration methods have made substantial developments, which offer opportunity for EDXRF to rely on chemical pretreatment process to overcome the above problems. In this work, two sets of experiments were carried out to establish on-site EDXRF methods for:1) accurate ore forming element analysis of multi-metallic ore after acid digestion of samples;2) heavy metal analysis in water samples after enrichment with ion exchange resin loaded filter paper specially made for the work. Experimental procedures and results are as follows:(1) Sealed digestion of samples by nitric acid and hydrofluoric acid, and EDXRF calibrations were done by utilizing standard solutions. Copper, lead and zinc in sulfide samples were quantified. The established method was verified with seven certified reference materials of multi-metallic ores GBW07162-GBW07168. Results show that almost all the precisions for copper, lead, zinc are better than5%(RSD, n=6),when their concentrations are greater than1%, and the results are in good consistency with the standard values.(2)Combined with the PE-EDXRF, two different procedures of ore sample digestion were tested on-site on multi-metallic ores for Cu, Pb Zn analysis:1)digestion in glass tubes in water bath with aqua regia,2) digestion in glass beakers on a hot plate with sequential adding of hydrochloric acid and nitric acid. These methods were calibrated by standard solutions and Compton scattering intensities of Mo Ka from the secondary target used as internal standard to compensate for the matrix effect. Two kinds of double cabin sample cups with acid absorbent and double supporting films were developed to prevent the spectrometer from damage by the possible leakage and evaporation in Qimantage area, Qinghai province(More than4000meters). When samples were pretreated using procedure2, the relative standard deviations (RSD, n=10) were less than2%for2quality control samples and relative errors were less than5.0%(element concentration were higher than0.5%) for4ones. PE-EDXRF results were compared with Atomic Absorption Spectroscopy(AAS) ones, the obtained mean relative deviation for Cu Pb and Zn were2.87%、2.82%、6.84%for the13local mine unknown samples. We conclude that the vehicle-loaded PE-EDXRF coupled with the double cabin sample cups and sample digestion procedures can solve the problem of matrix matching and offer a satisfactory solution for high precision on-site poly-metallic ore sample analysis. The work expand the capability of PE-EDXRF on-site analysis and improve the already established powder sample preparation method.(3) Ion exchange resin loaded filter papers were made, which were cut to fit the sample cups in the instrument before enrichment procedures. An ion exchange device was specially designed to allow repeated dynamic ion exchange without solution blending between repetitions. Primary ion exchange test and EDXRF measurement showed that the detection limits were as low as several ng/mL for Cu, Zn and Ni and about20ng/mL for Pb. Though the work is on its way yet, it has opened a door for the on-site EDXRF application in water quality monitoring.The above work has paved the way for the extended on-site application of portable and transportable EDXRF for mineral source exploration and water quality survey. The results has been summarized into two academic papers which have been accepted by the journal <Rock and mineral Analysis>, and three patents which are in the course of publicity.

化學前處理—能量色散X射線熒光光譜法應用于礦石及水體現(xiàn)場分析

摘要5-7Abstract7-8第一章 緒論10-21    1.1 X射線熒光光譜技術分析進展10-18    1.2 課題的學術背景及研究意義18-20    1.3 選題目的與主要內容20-21第二章 X射線熒光光譜法基本原理21-54    2.1 X射線概論21-26    2.2 特征X射線熒光26-28    2.3 X射線的吸收與散射28-31    2.4 X射線熒光光譜分析的特點31-32    2.5 能量色散X射線熒光光譜技術32-37    2.6 偏振能量色散X射線光譜儀37-39    2.7 X射線熒光光譜定性分析39-40    2.8 X射線熒光光譜定量分析40-44    2.9 X射線熒光光譜分析制樣技術44-49    2.10 X射線熒光光譜技術分類49-52    2.11 本章小結52-54第三章 酸消解-絡合緩沖溶液EDXRF分析硫化物礦石樣品54-61    3.1 實驗部分54-56    3.2 結果與討論56-60    3.3 結論60-61第四章 酸消解-車載EDXRF現(xiàn)場分析多金屬礦石樣品61-71    4.1 祁曼塔格找礦遠景區(qū)61-62    4.2 雙層膜液體樣品盒研制62-63    4.3 實驗部分63-66    4.4 結果與討論66-70    4.5 結語70-71第五章 離子交換特種紙富集水體重金屬元素的初探71-86    5.1 離子交換特種紙制備71-72    5.2 富集裝置72-73    5.3 實驗部分73-75    5.4 結果與討論75-84    5.5 小結84-86結論86-88致謝88-90參考文獻90-99個人簡歷99

  本文關鍵詞：化學前處理—能量色散X射線熒光光譜法應用于礦石及水體現(xiàn)場分析，，由筆耕文化傳播整理發(fā)布。