电感耦合等离子体发射光谱法测定硼硅酸盐玻璃中的硼等常见元素

硼硅酸盐玻璃中的硼、钙、镁、铝、铁、钛、硅等常见元素普遍采用各元素分别测定的方式进行分析,分析效率很低;而且硼的测定普遍采用容量法,当B2O3含量低于1%时,容量法测定误差较大。本文以KOH熔融的方式消解样品,采用电感耦合等离子体发射光谱法(ICP-AES)进行分析。通过实验研究了KOH用量和不同称样量对B2O3测定结果的影响。结果表明,KOH用量在3 g以上时有较好的熔样效率和熔样效果,称样量低于0.4 g对B2O3测定结果无明显影响,考虑到其他元素的测定,确定了KOH用量优选3 g,称样量优选0.1 g。在此条件下,测定B2O3等常见元素的精密度(RSD,n=6)≤2%,加标回收率在96.0%~105.6%之间,除Si O2测定误差较大外,其他元素的测定结果均令人满意。本方法确定的B2O3的定量限为0.067%,且对于B2O3最高含量达到16%的测定结果也令人满意,因此可测定B2O3含量的范围至少为0.067%~16%。当样品中的B2O3含量高于4%时,方法准确度和精密度与国家标准分析方法(容量法)相当;当B2O3含量低于1%时,方法准确度和精密度都优于容量法。与现有报道相比,本方法显著拓宽了B2O3的测定范围,并具有良好的准确度,而且在B2O3准确测定的同时,也实现了Ca、Mg、Al、Fe、Ti的定量分析和Si的半定量分析,大大提高了分析效率,可以实现硼硅酸盐玻璃中B2O3等常见元素的准确快速分析。     

江西赣县花岗岩型红土剖面常量元素地球化学特征

对赣县田村花岗岩红色风化壳剖面常量元素的迁移特征和化学风化强度的研究结果表明：（1）红土常量元素组成以 SiO2、Al2O3、Fe2O3为主,三者占总量的90%以上,其中又以SiO2的含量最高,K2O、CaO、Na2O与MgO等易溶组分的含量则 相对较低;（2）红土剖面风化过程中,常量元素的地球化学行为多表现为迁移淋失,迁移程度由剖面底部向上逐渐增强, 其中CaO与Na2O平均迁移量分别为97.34%、94.94%,属于强迁移元素;MgO、K2O和SiO2平均迁移量分别为52.50%、 39.89%、22.72%,属于易迁移元素,Fe元素表现为高度富集;（3）综合分析铝铁系数、化学蚀变指数和风化淋溶系数,指 示赣县花岗岩型红土在炎热、潮湿环境下遭受了强烈的化学风化作用,风化强度顶部向下渐弱。     

高温高压密闭溶样-电感耦合等离子体质谱法测定荧光粉中的杂质元素

提出了一种采用高温高压密闭溶样快速消解荧光粉晶体的前处理新方法。针对目前常用的稀土氧化物和稀土磷酸盐类、碱土金属铝酸盐类、碱土金属硅酸盐类四大类荧光粉,研究了消解时间、温度、消解溶剂种类和用量4个条件对样品消解程度的影响。采用电感耦合等离子体质谱法(ICP-MS)测定了最佳消解条件下消解的荧光粉中杂质元素Cu、Zn、Cd和Pb的含量。结果表明:稀土氧化物和稀土磷酸盐类荧光粉的最佳消解条件为 2 mL HCl溶剂中120℃下消解3 h;碱土金属铝酸盐类荧光粉的最佳消解条件为2 mL HCl溶剂中160℃下消解6 h;碱土金属硅酸盐类的最佳消解条件为2 mL HCl+0.5 mL HF溶剂中160℃下消解3 h。荧光粉中主要共存元素对所测杂质元素Cu、Zn、Cd和Pb的检测无干扰。该法线性范围宽、检出限低、灵敏度高,是荧光粉晶体中元素检测的较佳方法。     

X射线荧光光谱法测定高锶高钡的硅酸盐样品中主量元素

用百分总和检查硅酸盐岩石全分析数据的质量是分析工作者的传统做法,但对于微量元素含量较高的样品,采用X射线荧光光谱法(XRF)进行测定,如果不考虑微量元素的含量及其对主量元素基体效应的影响,往往会使主量元素含量更加偏离真实值。本文针对Sr、Ba含量较高的硅酸盐样品,通过人工配制标准样品,扩大了Sr、Ba校准曲线的定量范围,主量元素校准中加入Sr、Ba的基体校正系数,达到了主量元素定量更加准确可靠的实际效果。采用此方法分析国家标准物质,各主量元素的精密度(RSD)均小于2%;分析不参加回归的标准物质和人工配制的标准样品,主量元素的测量值与标准值(或参考值)基本一致。该方法可以满足硅酸盐的测定要求,主量元素各项结果的加和能够达到《地质矿产实验室测试质量管理规范》的一级标准(99.3%～100.7%)。     

地幔硫化物的物理化学性质及其地质意义

地幔硫化物是地球亲硫、亲铁元素的重要载体,与硅酸盐矿物有很大的物理性质上差别,它在高温高压条件下的物理化学性质是认识地幔物质组成及其不均一性的重要内容。此外,早期地球、火星、水星和月球幔部来源的硫化物对认识行星演化具有重要意义。地幔硫化物的存在条件、赋存方式以及元素分配系数受到硫化物和硅酸盐体系的化学平衡控制;硫化物在流体介质和固体介质中的迁移可以分别用斯托克斯方程和表面张力模型进行解释。基于目前的天然样品和实验研究结果,本文提出了地幔硫化物物理化学性质研究中尚存在的问题,并作展望：高温高压实验制约分配系数适用的元素含量远高于天然样品,导致亨利定律并不一定适用,要求开展元素含量更低的实验并进行测试;现有的线性或自然对数的经验方程不能准确描述硫化物-硅酸盐体系,机器学习可能揭示其错综复杂的热力学关系;硫化物熔体在深部地幔硅酸盐矿物表面的分布尚不清楚,对极端条件下的静水压力实验提出了需求。     

电子探针多道波谱仪同时测试同一个元素的方法：以石英中Al 和Ti 含量的测试为例

电子探针显微分析是常用的原位分析矿物中各种主量元素含量的技术方法,但是对于微量元素的分析,提高测试精确度和准确度长期以来面临着各种挑战。常用的提高精确度方法有改变加速电压、加大电流和增加计数时间,但是这些方法容易使样品遭到破坏,发生元素迁移从而造成测试结果的不准确,增加计数时间还会降低测试效率。文章提出了一种利用电子探针多道波谱仪同时测试同一个元素的方法来提高待测元素特征X射线的强度值。该方法利用电子探针不同波谱仪同时测试同一个待测元素,通过测试标准样品中待测元素的总净计数和待测样品中待测元素的总净计数,结合标准样品中待测元素的浓度计算待测样品中待测元素的含量。该方法在同等测试条件下可以有效的提高待测元素特征X射线的强度值,从而提高了测试的精确度,降低了测试的检测限。文章以石英中Al和Ti含量的测试为例,验证了多道波谱仪同时测试同一个元素的方法在微量元素测试中的应用。测试Al元素时使用一个TAP晶体和一个TAPL晶体,测试Ti元素时使用三个PETL晶体,结合多点背景测试法准确测试了石英中Al和Ti的含量,在20 kV电压、500 nA束流和20 μm束斑直径的条件下可将Al的检测限降低至2.6×10-6 (3σ),将Ti的检测限降低至2.1×10-6 (3σ),测试获得石英参考标样中Al和Ti的含量分别为163.8×10-6±5.8×10-6 (3σ)和56.5×10-6±2.0×10-6 (3σ),皆在参考值区间(Al：154×10-6±15×10-6;Ti：57×10-6±4×10-6)内,并且具有较好的长期稳定性。     

新疆阿克陶县有色矿石的非金属元素成分分析

岩矿测试和分析更多关注矿石矿物中的金属离子,但其中阴离子及其存在形式的研究对于理解矿石的组成、成因和金属离子的存在状态具有重要意义。本文采用红外光谱、X射线电子能谱和热重分析等方法对新疆阿克陶县奥依塔克镇的有色矿石中非金属元素进行成分分析。研究结果表明,矿石含有H、C、O、Si等非金属元素,主要以—C—O、C═O、Si—O—C和Si—O阴离子的形式存在,并与Mg、Al、Ca等主要金属元素形成γ-Al2O3、CaO·SiO2、MgCO3、CaCO3等化合物。样品煅烧到900℃,导致样品损失水分并使其中的MgCO3发生分解,而CaCO3不分解,分解产生的MgO与Si—O结合生成MgO·SiO2,表明矿石主要含有碳酸盐和硅酸盐,是具有白云石矿石特性的混合型矿石。     

电感耦合等离子体发射光谱法在地质样品分析中的应用进展

概述了电感耦合等离子体发射光谱法(ICP-AES)在测定技术方面的进展,强调该仪器测定条件对测定元素曝光强度的影响以及对测定中各元素分析谱线的选择和干扰元素的影响;介绍了ICP-AES测定技术在地质样品分析中的应用。测定土壤、岩石、水洗沉积物、矿石样品、植物样品和水样样品中的元素时,应根据样品性质的不同和测定元素的不同而采用不同的消解体系(酸溶法、碱熔法和微波消解法)。在测定土壤、岩石和水洗沉积物样品时,比较了不同消解体系各自的特点,同时也对比了采用不同消解体系时各元素的方法检出限,结果显示,酸溶法的检出限要明显优于碱熔法;在测定矿石样品时,对比了各元素在不同消解体系中的测定精密度,结果显示测定精密度均较好;总结了测定常见植物样品中无机元素的典型前处理方法以及ICP-AES测定水样中的元素全量和元素不同价态含量的方法。最后,对ICP-AES测定技术在地质行业的应用作了展望,相信ICP-AES还将在地质样品的分析中继续发挥作用。     

构造动力成岩成矿作用的实验研究

采用高温高压岩石蠕变实验装置,对实际的岩石进行高温高压变形实验,通过观察和测试样品组构和成份的变化,考察一定温压条件下,岩石的构造变形所带来的物质组分的迁移和聚集,探讨构造动力控制成岩成矿作用的机理。实验结果表明:伴随构造变形,物质组分迁移 主要可归纳为三种类型:1)塑性或韧性流动;2)扩散与化学反应;3)热液携带。在实验后的样品中观察到:黄铣矿通过韧性流动沿韧性剪切带,韧性挤压带和韧性扭曲构造带的迁移和富集;斜长石和黑云母发生矿物成份和矿物相的转化。在实验变形过程中,Cu,Pb,Zn等成矿元素易于活化迁移,从高压区迁向低压区,K,Na,Ca,Mg等成岩元素也易活化迁移,但规律不明显,Fe,Co,Ni等元素对花岗岩样品不易活化迁移而对矿石样品则易迁移。上述实验结果对探讨成矿规律具有非常重要意义。     

凡口铅锌矿床地气样品元素分析及远景区预测

地气法是较新发展起来的地球化学勘探方法,地气是指从地球内部上升至地球表层的气体,主要包括H2O,CO2,H2S,NH3,H2,N2,CH4,He,Rn,Ar。研究证实,地气在经过矿体时可以将含有相关元素的物质携带并迁移至地表造成地球化学异常。据此,可通过采集地气样品,分析其中的元素成分及含量,推测地下的物     

Activities and volatilities of trace components in silicate melts: a novel use of metal–silicate partitioning data

Ian Carmichael spent 45 years thinking about and working on the activities of components in silicate melts and their use to estimate physicochemical conditions at eruption and in the source regions of igneous rocks. These interests, principally in major components such as SiO₂, led us to think about possible ways of determining the complementary activity coefficients of trace components in silicate melts. While investigating the conditions of accretion and differentiation of the Earth, a number of authors have determined the partitioning of trace elements such as Co, Ni, Mo and W between liquid Fe metal and liquid silicate. These data have the potential to provide activity information for a large number of trace components in silicate melts. In order to turn the partitioning measurements into activities, however, we need to know the activity coefficient of FeO, γ_FeO in the silicate. We obtained γ_FeO as a function of melt composition by fitting a simple model to 83 experimental data for which the authors had measured the FeO content of the silicate melt in equilibrium with metal (Fe-bearing alloy) at known f_O2. The compositional dependence of γ_FeO is weak, but, when calculated in the system Diopside–Anorthite–Forsterite, it decreases towards the Forsterite apex. A similar approach for Ni, for which twice as many data are available, leads to similar composition dependence of activity coefficient and confirms the suggestion that γ_NiO/γ_FeO is almost constant over a wide range of silicate melt composition. The activity coefficients for FeO were used in conjunction with measured Mo and W partitioning between Fe-rich metal and silicate melt to estimate activity coefficients for trace MoO₂ and WO₃ dissolved in silicate melt. When combined with data on Mo- and W-saturated silicate melts a strong dependence of activity coefficient is observed. Calculated in the system Diopside–Anorthite–Forsterite, both MoO₂ and WO₃ exhibit similar behaviour to FeO and NiO in that activity coefficients decrease as Forsterite content increases. The effect is much larger for Mo and W, however, γ_MoO2 and γ_WO3 varying by factors of 20 and nearly 100, respectively, in this system. In order to illustrate the potential applications of the metal–silicate partitioning approach to determine the activity coefficients of volatile elements, we used it to determine activity coefficients of PbO, CuO_0.5 and InO_1.5 in a silica-saturated melt at 1,650 °C. We find values of 0.22, 3.5 and 0.02, respectively, indicating a strong dependence on cation charge. The value for CuO_0.5 is in excellent agreement with experimental data of Holzheid and Lodders (Geochim Cosmochim Acta 65:1933–1951, 2001), which shows that the method is viable. When combined with thermodynamic data on the gas species, we find that Pb is the most volatile of the 3 elements under ‘normal’ terrestrial conditions of oxygen fugacity but that In should become the most volatile under strongly reducing conditions such as those of the solar nebula. The oxygen fugacity dependence of volatility has implications for the high relative abundance of In in silicate Earth. We conclude that metal–silicate partitioning experiments are a viable means for determining activities of trace components in silicate melts and are particularly useful if the metal of the element is unstable or volatile at igneous temperatures.     

偏硼酸锂碱熔-电感耦合等离子体发射光谱法测定硫化物矿中硅酸盐相的主成分

通过实验发现偏硼酸锂不能有效分解硫化物矿,但可有效分解其中以氧化物存在的造岩元素,从而可测定硫化物矿中硅酸盐相的二氧化硅、三氧化二铝、氧化钙、氧化镁、氧化钾、氧化钠、二氧化钛、氧化锰、五氧化二磷共9个主要组分。实验确定了用电感耦合等离子体发射光谱法测定硫化物矿的分解条件及测定条件。对铜、铅、锌(银)矿石与精矿成分分析标准物质GBW 07162~GBW 07168以及硫化物单矿物标准物质GBW 07267~GBW 07270进行分析测定,方法精密度(RSD)<7%,准确度(RE)<5%,能够满足样品分析中各元素定量分析的要求。同时向定值不全的硫化物标准物质中加岩石标样GBW 07105做流程加标试验,回收率大部分在90%~110%。     

Experimental Study of Partial Melting of Mantle Peridotite--A Discussion about the Genesis of Silica-rich Fluids (Melts)

Experiments on partial melting of mantle lherzolite have been realized at 0.6 and 1.0 GPa and the chemical compositional variations of melts during different melting stages have been first discussed. The results show that the trends of variations in SiO2, CaO, Al2O3, Na2O and TiO2 are different at different melting stages. The melts produced at lower pressure are richer in SiO2 than those at higher pressure. The mantle-derived silica-rich fluids (silicate melts) are polygenetic, but the basic and intermediate-acid silicate melts in mantle peridotite xenoliths from the same host rocks, which have equivalent contents of volatile and alkali components and different contents of other components, should result from in-situ (low-degree) partial melting of mantle peridotite under different conditions (e.g. at different depths, with introduction of C-O-H fluids or in the presence of metasomatic minerals). The intermediate-acid melts may be the result of partial melting (at lower pressure) Opx + Sp + K-Na-rich fluid±(Amphi)±(Phlog)= Ol+melt.But the intermediate-acid magmas cannot be produced from the partial melting of normal mantle peridotite unless the crustal materials are introduced to some extent.     

硅酸盐矿物微量化学分析

用微量技术进行化学分析,可以比一般的常量技术大大节省矿物样品消耗,较早的硅酸盐矿物微量分析方法能够取得准确的全分析结果,但是要求很高的个人实验技术,而且方法已经过时。国内目前流行的少用样品的方法误差过大,不能适应地质科学研究要求。本文提出一个比较准确而又不要求分析人员具有特殊技术训练的实用有效的微量化学分忻方法,其中只使用一般化验室的常用设备。 这个分析方法包括SiO_2、Al_2O_3,Fe_2O_3,FeO,MgO,CaO,Na_2O,K_2O,H_2O+、H_2O、P_2O_s、TiO_2,MnO,BaO和F,共15项目。方法中保留必要的系统分析以节省样品,采取充分利用称样的方法简化操作技术,同时保证容量法有足够的准确度。全分析共消耗矿物65mg。此方法中SiO_2和BaO禾用重量法,Al_2O_3、Fe_2O_3T、MgO和CaO采用容量法。文中比较详尽地描述了分析技术,对于已有硅酸盐经典分析经验的分析人员不难掌握。除了将常用的比学分忻方法实行微量化以外,对于SiO_2,H_2O+、F等项目采用新的微量方法和仪器,对于Fe_2O_3和Al_2O_3用同一份溶液成功地实行连续测定,节省了样品。 此方法节约试剂,操作迅速,已成功地用于分析多种硅酸盐矿物(白云母、黑云母、角闪石,石榴子石、斜长石)。     

The effect of fluorine, boron and excess sodium on the critical curve in the albite–H2O system

Experiments to define the critical curve for a series of silicate melts in equilibrium with a hydrous fluid were carried out in a hydrothermal diamond anvil cell. Silicate compositions studied were albite with several wt% excess Na₂O, B₂O₃ and F₂O_-1. Complete miscibility between melt and water was observed at lower pressure and temperature conditions compared to pure albite for all compositions. For albite + excess Na₂O, the critical curve had been lowered by 143 and 247 °C at 10 kbar for 5 and 10 wt% excess Na. For albite +5 and 10 wt% F, the difference at 10 kbar was 147 and 246 °C respectively, and for albite +5 and 10 wt% B differences of 168 and 262 °C were found. These results are likely to be additive, with the presence of more than one of the components depressing the critical curve to even lower temperatures and pressures. The results suggest that in complex pegmatitic systems, complete miscibility between melt and fluid may be important in the final stages of crystallisation. The unusual properties of fluid phases under conditions close to the critical curve in a silicate melt-water system may be essential for the enrichment of trace elements in pegmatites as well as for the formation of typical pegmatite textures.     

Origin of silicate minerals in carbonatites from Alnö Island,Sweden: magmatic crystallization or wall rock assimilation?

Textural, electron microprobe and whole rock geochemical evidence from carbonatites and associated silicate rocks on Alnö Island, Sweden, suggest that the carbonatite, at the time of emplacement, could have been an (almost) pure CaCO₃ liquid with a high volatile (H₂O–CO₂) content and that most silicate minerals, which are ubiquitously present, are either (1) assimilated from the surrounding wall rock, by progressive and coupled fragmentation and corrosion; or (2) by‐products of corrosive interaction between the carbonatite liquid and the wall rock. This interpretation is supported by balancing a reaction to describe interaction between carbonatite and a cpx + ne‐bearing (ijolite) wall rock. Although our analysis does not preclude the possibility that fenitizing agents (e.g. Na, Fe) were transported by the carbonatite liquid, these components are not required to drive the observed mineralogical changes in the carbonatite.     

X射线荧光光谱法测定含金石英石中7种成分

采用粉末直接压片,波长色散多道荧光光谱法快速测定含金石英石样品中SiO2、Al2O3、TFe2O3、CaO、MgO、Pb、Zn等7种成分。根据含金石英石中SiO2的含量范围,选取了与试样基体相匹配的含金石英生产样作为校准样品,采用化学法准确定值,确定了仪器的最佳分析参数。对于Si和Al轻元素,荧光强度随粒度变化较为显著;制作的校准样品应密封保存,粉末压片后需马上进行测试。方法操作简单,成本低,测定范围宽,灵敏度高,精密度(RSD,n=11)均小于2.5%。与化学法对照,结果符合较好。     

硅酸盐体系的化学平衡:(2)反应热力学

通过具体的应用实例,系统介绍了在矿物材料学研究中硅酸盐体系的多相平衡反应热力学的基本原理。对硅酸盐体系的典型多相平衡反应进行了热力学计算,包括:(1)微晶玻璃制备过程中的硅酸盐熔融反应;(2)霞石正长岩和高铝粉煤灰利用技术中的硅酸盐烧结反应;(3)S iO2-CaO-H2O体系和KA lS i3O8-CaO-H2O体系雪硅钙石、硬硅钙石的水热晶化反应;(4)高铝粉煤灰和霞石正长岩烧结产物的溶解反应;(5)Na[A l(OH)4]-A l(OH)3-H2O体系和Na2SO4-Ca(OH)2-H2O体系中α-A l(OH)3和CaSO4.2H2O的析晶反应。研究成果可望对矿物材料制备实验方案设计、工业生产过程优化及改进产品性能提供理论指导,同时为同类材料学研究提供借鉴。     

中国富钾正长岩资源与水热碱法制取钾盐反应原理

中国的盐湖钾盐资源短缺,导致钾盐消费的对外依存度达50%以上,严重制约农业发展,威胁粮食生产安全。而正长岩型钾资源丰富,K2O品位达8.5%~15.4%,预测资源潜力(K2O)达盐湖钾盐储量的20倍以上。此类矿石钾资源的主要富钾矿物为微斜长石、霞石和白云母,地理上主要分布于中国东部的“秦岭大别正长岩带”和“燕辽阴山正长岩带”。采用电解质溶液热力学软件OLI Analyzer 9.2,对KAlSi3O8-NaOH/KOH/Ca(OH)2-H2O体系相平衡进行模拟,继而对代表性富钾正长岩进行水热碱法分解反应实验,证实K2O溶出率高达85.6%以上。所得硅酸钠钾碱液适于加工多种钾盐或生态型钾肥产品,硅铝组分同时转化为沉淀硅酸钙、钠型/钾型沸石、硅灰石、高岭土等多种工业产品。水热碱法技术的加工过程清洁高效,资源利用率高,环境相容性良好,可为发展绿色可持续的中国钾盐工业新体系提供良好的技术基础。     

Quantification of Water Content and Speciation in Synthetic Rhyolitic Glasses: Optimising the Analytical Method of Confocal Raman Spectrometry

Quantification of water content in silicate glasses is of vital significance in understanding magma evolution and metamorphic anataxis. Here we provide a method for the determination of total dissolved water content and water speciation in silicate melts by confocal laser Raman spectrometry based on a set of hydrous rhyolitic glasses. A series of alumino-silicate glasses with water contents from 0.33 to 9.05% m/m were synthesised in a piston cylinder apparatus. Synchrotron-FTIR mapping shows that these glasses have relatively homogeneous distributions of dissolved water. Total water contents of the glasses were precisely measured by TC/EA-MS and FTIR. Both external and internal calibration were established for the quantitative analysis of water content and water speciation in the silicate glasses based on excellent linear correlation between total dissolved water content and integrated area of the water Raman band. Furthermore, by decomposing the total water Raman bands into four Gaussians components, the relative concentration of water speciation (OH groups and molecules H₂O_m) dissolved in the glasses was determined with a similar trend to water speciation data derived from FTIR. We suggest that the relative concentration of water speciation can be estimated in rhyolitic glasses with 4–8% m/m H₂O. Our work provides an accurate method to determine total water content and a potential tool to limit the relative concentration of water speciation dissolved in silicic glasses.