石英中有害杂质元素分布特征和赋存状态及提纯方法

对石英原料的加工分选提纯,是获得高纯石英原料的主要途径,而有关对石英晶体中有害杂质的分选提纯,国内对这方面的工作较少。根据水晶、石英的ICP分析结果,对水晶石英晶体中的有害杂质元素主要种类、分布特征、在晶体中的赋存状态及提纯方法,分别进行了讨论。     

关于高纯石英原料矿石地质学评价方法的探讨

高纯石英资源是一种重要的战略性资源。本文结合高纯石英成矿地质特征及其对后期选矿提纯、材料加工等的影响, 系统总结了高纯石英原料中杂质的赋存状态、形成机理以及评价方法等, 得出: (1)可以作为高纯石英原料的潜在岩石类型有花岗伟晶岩(包括不含暗色矿物的伟晶状花岗岩)、脉石英以及水晶, 岩浆演化晚期的伟晶状花岗岩-伟晶岩早期阶段的NYF型花岗伟晶岩结晶形成的石英纯度更高, 后期适当的变形变质作用更有利于高纯石英矿床的形成。高纯石英原料矿石中石英矿物呈现无色透明至半透明, 矿物构造裂隙少, 伟晶岩型矿石矿物组成通常为石英、钠长石、条纹长石、白云母等, 黑云母等暗色矿物含量极少, 基本不见锂辉石、独居石等稀有金属矿物和电气石、萤石等含挥发分矿物。(2)影响高纯石英的主要地质因素包括脉石矿物及晶界杂质、包裹体、晶格杂质等。其中包裹体类型、数量和尺寸是包裹体评价的关键指标, 天然石英矿物中的气液两相包裹体、矿物包裹体和 < 10μm包裹体应尽量少; Al和Ti是晶格杂质元素评价标志性元素, 通常要求天然石英矿物中Al < 50×10^-6和Ti < 10×10^-6。(3)建议按照手标本特征-石英矿物特征-石英中包裹体特征-晶格元素赋存状态及含量的顺序, 从宏观到微观, 综合借助光学显微镜、扫描电子显微镜(SEM)、阴极荧光光谱分析系统(SEM-CL)、激光剥蚀电感耦合等离子质谱仪(LA-ICP-MS)等开展地质学评价和研究工作。

     

高纯石英的研究进展及发展趋势

石英是一种在地壳上大量分布,有着广泛工业用途和广阔应用前景的矿物。当石英晶体形成演化时,受结晶时环境条件、流体性质、结晶后遭受改造(如变质作用、构造变形和热扰动等)等影响,杂质元素如P、Ti、Ge、Al、B、Be、Ca、Na、K、H、Li等会或多或少存在于石英晶体中,因此在自然界不存在纯SiO₂组分的石英。同时,基于石英的微量元素组成,可以反演石英源区和形成演化过程,并用于研究岩石及矿床成因等科学问题。石英晶体内部杂质元素以类质同象替代、气液包裹体、矿物包裹体(不能按尺度分,应该按照状态划分存在形式)3种形式存在。石英中杂质元素的种类、含量、赋存形式,特别是包裹体特征将直接影响石英资源的品质和工业用途。本文还系统地阐述了石英的发光特性、工艺性能以及高纯石英的质量分类与标准和高纯石英原料来源等方面的内容。在本研究中,通过光学显微镜和激光拉曼测试,初步地查明了苏北张锦庄石英砂和广西姑婆山花岗岩石英中流体包裹体的分布和矿物包裹体的种类,这是开展后续研究的基础。高纯石英是优质石英资源经纯化加工得到的高品质石英原材料,可用于石英玻璃、石英坩埚、半导体、高温灯管、光纤、精密光学、微电子和太阳能等高新技术产业中。研究高纯石英原料的评价体系、理想源岩和形成机制有益于持续性地供给高纯石英原料, 极大地提高了石英原料的工业附加值。     

鄂东南付家山脉石英矿杂质特征及其用作高纯石英原料的潜力

作为战略性矿产资源之一,高纯石英已广泛应用于集成电路、半导体芯片、太阳能等高新技术产业中,但是能够生产高纯石英的原料矿床极为稀缺,我国尤为紧缺高纯石英原料矿。鄂东南地区是湖北省脉石英矿床的主要分布区。本文针对鄂东南付家山脉石英矿床,通过光学显微镜、扫描电子显微镜观察了脉石英的脉石矿物类型和包裹体特征,采用电感耦合等离子发射光谱法(ICP-OES)对原矿进行了微量元素分析,旨在获得付家山脉石英矿床的杂质元素特征,进而评价矿床用作高纯石英原料的潜力。结果表明,付家山脉石英矿石SiO₂含量大于99.95%,杂质元素主要为Al、K、Fe、Ti、Ca等,脉石矿物主要有白云母、钾长石、铁氧化物等,流体包裹体较为发育。杂质元素分析结果表明,付家山脉石英原矿质量达到低端高纯石英标准,经传统工艺提纯后,可能具有生产中高端高纯石英的潜力。     

我国高纯石英加工技术现状与发展建议

高纯石英是晶硅、石英玻璃和集成电路基板材料等生产的重要原料,在新能源和新材料等战略性新兴产业具有重要的地位和作用.为了促进我国高纯石英技术发展,介绍了高纯石英的一般概念及其主要品种,并在评述我国高纯石英加工技术现状基础上,针对存在的主要问题,提出加强我国高纯石英矿物资源地质勘查工作、矿物学应用基础研究、提纯加工技术与装备研究、产品质量标准和检测技术研究等具体建议.     

微波在高纯石英提纯实验中的应用

随着水晶资源的日益枯竭,利用脉石英制备高纯石英以代替水晶已经成为一项需要迫切解决的技术问题。高纯石英中,铁杂质是最主要同时也是对产品质量影响最大的有害杂质之一,如何有效地除去脉石英中的铁杂质一直就是高纯石英生产中的难点和重点。当前主要是用酸浸的方法降低铁杂质的含量,主要存在的问题是处理时间较长,同时铁杂质含量也不容易降得更低。通过对微波在高纯石英提纯实验中应用的研究,表明微波可以有效地“打开”石英矿物中含铁的包裹体,不仅能促进含铁杂质矿物的酸浸去除,还可以极大地加快酸浸的速度,促进高纯石英的生产,同时为微波技术在高纯石英生产中的应用奠定了坚实的基础。     

高纯石英矿物资源工程研究

高纯石英是世界稀缺和我国短缺的高技术战略矿物资源,是石英晶格Al杂质的质量分数≤30×10-6的天然矿物,晶格Al及其他粒内杂质元素有均匀、非均匀,环带三种分布形式,其含量和分布形式是决定产品纯度及提纯工艺限度的根本因素。无同期伴生金属矿化是高纯石英矿床成矿的必要条件,预测和寻找大型高纯石英矿床可类比美国伟晶白岗岩型矿床。高纯石英矿物工程前沿技术是除高杂石英、除粒内杂质及粉碎整形。国家主导大型高品质高纯石英矿床预测找矿是发展我国高纯石英产业的关键。     

中国高纯石英产业链现状及发展建议

高纯石英是世界稀缺、中国短缺资源,关系到中国的半导体芯片、光伏和航空航天等关键性新兴产业发展。通过对中国目前高纯石英产能不足、加工技术相对落后等现状分析,揭示缺少高纯石英质量评价标准是制约中国高纯石英产业发展的关键因素,国内缺少高品质优质原料矿是制约中国高纯石英产业健康发展的“卡脖子”问题。进一步研究指出,在新一轮找矿突破战略行动中,加强产学研用相结合,公益性勘查项目优选一批可供出让的优质高纯石英原料矿的勘查区块,拉动商业勘查,提升高品质优质原料矿的供应能力,切实保障中国高纯石英产业链安全。     

高纯石英原料特征和矿床成因研究现状综述

高纯石英具有重要的战略地位,是高新技术产业的基础原材料。本文对高纯石英原料的特征和矿床成因研究方法进行了系统的归纳。通过观察石英岩相学特征,分析矿物包裹体及流体包裹体的数量、大小、化学成分、存在形式和分布状态,以及SiO2和微量杂质元素的含量和赋存状态,可以研究高纯石英原料的矿物学特征;通过Ar Ar同位素定年可以计算高纯石英原料矿床的成矿年龄;通过H—O同位素测试,Ti、Al、Ge、Li等微量元素含量分析,可以研究高纯石英原料矿床的成矿物质来源;通过分析流体包裹体的均一温度、盐度、化学组成等特征以及SEM CL微结构观察,可以研究高纯石英原料矿床的成矿作用过程。在此基础上,本论文对我国高纯石英行业的发展提出相关的建议。     

高纯石英原料特征和矿床成因研究现状综述

高纯石英具有重要的战略地位,是高新技术产业的基础原材料。本文对高纯石英原料的特征和矿床成因研究方法进行了系统的归纳。通过观察石英岩相学特征,分析矿物包裹体及流体包裹体的数量、大小、化学成分、存在形式和分布状态,以及SiO2和微量杂质元素的含量和赋存状态,可以研究高纯石英原料的矿物学特征;通过Ar Ar同位素定年可以计算高纯石英原料矿床的成矿年龄;通过H—O同位素测试,Ti、Al、Ge、Li等微量元素含量分析,可以研究高纯石英原料矿床的成矿物质来源;通过分析流体包裹体的均一温度、盐度、化学组成等特征以及SEM CL微结构观察,可以研究高纯石英原料矿床的成矿作用过程。在此基础上,本论文对我国高纯石英行业的发展提出相关的建议。     

Mineralogy and physico-chemical properties of Wadi Badaa clays (Cairo-Suez district,Egypt): a prospective resource for the ceramics industry

The Wadi Badaa (WB) Upper Miocene clays, Cairo-Suez district, Egypt, represent materials for the ceramic production. The clay raw materials are composed mainly of smectite and kaolinite with minor quartz, calcite, and rare feldspar. The plasticity indices vary between 24 and 30%, suggesting that these clays are plastic raw materials. IR bands of the investigated clays were observed at 3695, 3619, 1032, 916, 794, 690, 534, 466, and 423 cm^?1 for kaolinite; at 3436, 1635, 916, and 466 cm^?1 for smectite; and at 1179, 1104, 794, 690, and 466 cm^?1 for quartz. The <2 μm particle sizes of samples are relatively abundant in clays (～33%), which is adequate for uses of the ceramic products because of containing fine particle sizes. The studied WB clays contain 7.95 and 12.35% moisture water and interlayer water, respectively, with a maximum drying shrinkage of 7.87% at room temperature; therefore, the WB clays could be used in the ceramic manufacture.     

晋北煅烧高岭土用煤矸石的应用矿物学特征

为了给晋北煅烧高岭土用煤矸石的评价和开发利用提供科学依据,采用XRD、XRF、SEM和白度计等现代分析测试技术,研究了晋北煅烧高岭土用煤矸石的应用矿物学特征。结果表明:1)根据造纸和涂料用煅烧高岭土的国家标准,晋北煤矸石主要可分为3种类型:合格原料、基本合格原料和不合格原料。2)与合格和基本合格原料相比,不合格原料煅烧产物的化学成分中SiO₂、Al₂O₃、Fe₂O₃含量以及碱金属与碱土金属总含量都与前者有较大差异。3)合格和基本合格原料主要由高岭石(85%～94%)组成,不合格煤矸石矿物组合为高岭石(30%～60%)+石英(23%～38%)+伊利石(14%～26%),并含少量黄铁矿和白云石等杂质矿物,石英等杂质矿物和含铁矿物是分别导致煅烧产物化学成分和白度不合格的主要原因。4)合格原料中高岭石结晶度较好,主要为不规则片状、书册状和弯曲片状,片表面光滑,片径大小范围较大,为0.05～51.22μm,平均2.80μm,径厚比41.24。     

Quartz resources in the Serra de Santa Helena formation,Brazil: A geochemical and technological study

This study presents an evaluation of Brazilian quartz deposits of Corinto and Olhos D'água, in Minas Gerais State, as potential high purity raw material for the production of silica glass. Both deposits are part of the Serra de Santa Helena formation, which holds other quartz deposits. Several quartz samples from these mines were analyzed to evaluate their chemical purity, by determination of the content of trace elements by ICP-MS after acid digestion. The technological characteristics of the ores after flame-fusion into silica glass were evaluated according to their bubble generation and UV transparency. The results indicate that silica glass with chemistry suitable for crucible applications can be obtained from materials of both mines, and even optical grade silica glass can be manufactured using transparent ore from one of the mines. In addition, this work explores the trace elements composition of each mine, as well as their fluid inclusions, and characterizes the mines as being of hydrothermal origin. Small differences in the physical and chemical characteristics of quartz that could affect the technological behavior of the ores are related to the geological history of the mines and provide interesting insights regarding the exploration of other quartz resources within the same geological formation.     

不同成因类型石英与石英玻璃气泡缺陷间关系探讨

对不同成因类型石英的气液包体含量与石英玻璃气泡缺陷间的关系进行了对比研究，总结了一些规律，对石英玻璃工业原料的地质找矿具有一定的指导意义。     

The chemical composition including the Rare Earth Elements of the three major glass types of Europe and the Orient used in late antiquity and the Middle Ages

Sets of 20 soda ash glasses, 16 soda lime glasses and 23 wood ash glasses mainly from excavations in Europe (additional soda ash glasses from Egypt) were analysed on 61 chemical elements. Average SiO₂ is about 62% in soda glasses and 50% in wood ash glasses. The three groups of glasses contain on average 13% Na₂O, 18% Na₂O and 13% K₂O as fluxes to lower the melting temperature of quartz at their production. The starting materials beside quartz were halophytic plant ash for soda ash glass, trona (Na₃H(CO₃)₂·2H₂O) and lime (clamshells) for soda lime glass and beech ash for wood ash glass. Each of the three major glass types contains specific Rare Earth Element (REE) concentrations mainly contained in quartz and its intergrown minerals. 50 Paleozoic and Mesozoic sandstones from Central Europe represent the quartz composition. The REE pattern of these glasses apparently indicates major compositional stages of the Continental Earth's Crust. The boron to lithium and sodium to potassium ratios as in seawater suggest reactions of materials for soda glass with seawater. Negative Ce anomalies in the three glasses are caused by reactions of quartz with seawater.     

粉石英在微孔硅酸钙保温材料中的应用研究

本文介绍了一种新的优质硅质原料－－粉石英，着重探讨了它的矿物组成、粒度分布、物化性质及其合成硅酸钙的试验。试验结果表明，粉石英与石在高温、高压和搅拌的条件下，可以合成硅硅钙石型优质微孔硅酸钙制品。为微孔硅酸钙行业开发了一种新的质优、价廉的硅质原料。     

Geochemical characteristics and spectrometric prospecting in the muscovite-bearing pegmatites and granites,southeastern Aswan,Egypt

Rare metal mineralization of Sn, Nb-Ta and W is encountered in the Gebel Dihmit area （GDA）, southeastern Aswan, Egypt. The mineralization is related to muscovite granites and their pegmatite derivatives. The pegmatites are divided into three types according to their main mineral assemblages： K-feldspar-muscovite-tourmaline, K-feldspar-albite-muscovite and albite-K-feldspar-lepidolite veins. Petrogenetic studies indicate that Sn and Nb-Ta mineralization extends from the late-magmatic stage to the pegmatite and hydrothermal stages of the （GDA） suite. The albite-K-feldspar-lepidolite granite is composed dominantly of albite, lepidolote, and quartz, with topaz, K-feldspar and amblygonite. The accessory minerals are zircon, monazite, pollucite, columbite-tantalite, microlite and Ta-rich cassiterite. Phenocrysts of quartz, topaz and K-feldspar contain abundant inclusions of albite laths and occasional lepidolite crystals along growth zones （snowball texture）, indicating simultaneous crystallization from a subsolvus, residual magma. The origin of the pegmatites is attributed to extreme differentiation by fractional crystallization of a granitic magma. The economic potential for rare metals was evaluated in the geochemical discrimination diagrams. Accordingly, some of the pegmatites are not only highly differentiated in terms of alkalis, but also the promising targets for small-scale Ta and, to a less extent, Sn. The pegmatites also provide the first example of Fe-Mn and Nb-Ta fractionation in successive generations of granites to cassiterite-bearing pegmatites, which perfectly ex- hibit similar fractionation trends established for primary columbite-tantalite in the corresponding categories of pegmatites. Uranium and Th of magmatic origin are indicated by the presence of thorite and allanite, whereas evidence of hydrothermal mineralization is the alteration of rock- foring minerals such as feldspar and the formation of secondary minerals such as uranophane..