青海省铝、镁、锂金属资源开发利用现状

对青海省的铝、镁、锂资源及开发利用现状做了介绍,也涉及到了国内、国际有关方面的发展状况和动态。     

Tantalum-bearing titanite: synthesis and crystal structure data

Synthetic titanite, CaTiOSiO₄, and the series of (Ca_1−x Na _x )(Ti_1−x Ta _x )OSiO₄ and Ca(Ti_1−2x Ta _x Al _x )OSiO₄ solid solutions have been prepared by ceramic methods, and their crystal structure determined by the Rietveld analysis. At ambient conditions, titanite can contain up to 20 mol% NaTaOSiO₄ or 60 mol% Ca(Al_0.5Ta_0.5)OSiO₄. These limits might differ in natural samples due to combination with substitutions involving fluorine and/or hydroxyl replacing oxygen together with vacancies at cationic sites. All cations located at the ^vii X- and ^vi Y-sites in the structures of tantalian titanite are disordered. Expansion of the <Si–O> bond from 1.618 to 1.621 Å in CaTi_0.8Ta_0.1Al_0.1OSiO₄ and CaTi_0.6Ta_0.2Al_0.2OSiO₄ to 1.644 Å in the CaTi_0.4Ta_0.3Al_0.3OSiO₄ titanite suggests the possible presence of some Al³⁺ in the tetrahedral site replacing Si⁴⁺ in the latter. All tantalian titanites crystallize in the space group A2/a. This implies that both single-site and complex double-site substitutional schemes induce P2₁/a → A2/a phase transition(s). The (Ca_1−x Na _x )(Ti_1−x Ta _x )OSiO₄ substitution scheme incorporates larger cations at both the ^vii X and ^vi Y sites, whereas the Ca(Ti_1−2x Ta _x Al _x )OSiO₄ scheme involves only ^vi Y-site (Al³⁺,Ta⁵⁺) cations with a slightly smaller “average” radius. Unit cell dimensions change insignificantly or increase incrementally with increase of average cationic radii in the (Ca_1−x Na _x )(Ti_1−x Ta _x )OSiO₄ series, and with an insignificant decrease in the ^viR _Y average cationic radii in the Ca(Ti_1−2x Ta _x Al _x )OSiO₄ series. Both Ta-doped titanite and CaTiOSiO₄ consist of distorted polyhedra with the XO₇, YO₆ coordination polyhedra and the SiO₄ tetrahedron in tantalian titanite being less distorted compared to those of the pure CaTiOSiO₄.     

江苏发现的硼锡钙石及其研究

硼锡钙石是一种罕见的岛状硼酸盐矿物,其化学式为CaSn[BO_3]_2。一轴晶,负光性,折光率No=1.774,Ne=1.661,比重为4.09,发育{0001}解理,乳白色。矿物产于苏州花岗岩与大理岩接触带矽卡岩中的一个萤石矿床内。它是一种富含硼、氟的高温气液流体作用于钙质围岩而发生交代的产物。它的发现,不仅对矿物产状提供了新的资料,而且对锡、硼的地球化学以及硼酸盐矿物的研究也具有一定的学术意义。     

Vibrational Spectroscopic Analysis of Borates in Mother Liquid of Brine after Potassium Separated

正It is well known that boron exists as polyborate anions in aqueous solution.Boron atom can coordinates to three or four oxygen atoms and borate can exist as not only the monomer but also the polymer.The polymerization     

湖南七里坪－半边街镁质矽卡岩硼矿床微量元素地球化学

湖南七里坪－半边街接触交代型硼矿，矿体产于中石炭统壶天群白云岩与燕山期花岗岩接触带的矽卡岩中，产状受岩体顶板形态的控制，多为似层状、透镜状、囊状等。一般离岩体较远的部位硼矿石的品位较富，但靠近岩体的部位矿体较厚大。据微量元素相关系数聚类谱系图分析，Ｂ元素在岩体中呈分散状态，在高温热液中易于聚集，在矽卡岩中富集成矿，在蚀变的白云岩中有轻微的富集。     

与遂安石共生的电气石矿物学特征及其地质意义

在对宽甸砖庙硼矿床的研究中发现了电气石与遂安石共生的现象,电气石为钙镁电气石,由电子探针分析结果计算的晶体化学式为:(Ca_0.59Na_0.355K_0.06)(Mg_2.557Fe_0.1512+Ti_0.013Cr_0.002Ni_0.006)(Al_5.416Fe_0.5642-（BO₃）₃Si _6.16 O₁₆（OH）₄,同围岩中的电气石相比:（1）淡绿色,多色性弱;（2）折射率为Ne=1.646,Ns=1.624;（3）成分上富Mg（MgO 11.47％）和Ca（CaO3.14％）;相对贫Na（Na₂O 1.09％）,Fe（FeO4.63％）和Al（Al₂O₃26.69％）（4）结构上d₁₀₁=3.393A,a₀=15.957±0.002,c₀=7.227±0.001;（5）红外光谱晶格Si-O₄四面体振动I₁₀₀₁>I₁₀₃₆。这些标型特征具有硼矿床的找矿指示意义。     

Comparison of Fused Glass Beads and Pressed Powder Pellets for the Quantitative Measurement of Al,Fe, Si and Ti in Bauxite by Laser‐Induced Breakdown Spectroscopy

Due to matrix interference and sample particle size effects, some of the most important and difficult issues in laser‐induced breakdown spectroscopy (LIBS) analysis are the calibration and quantitative measurement of a complex matrix. This study proposes the use of borate fusion as an alternative sample preparation procedure for the quantitative measurement of Al, Fe, Si and Ti in bauxite by LIBS. Analytical calibration curves were made using bauxite certified reference materials (CRM), and the precision and accuracy of the methods were evaluated by analysing an additional bauxite CRM, using two different approaches: pressed powder pellets and fused glass beads. The borate fusion method was the most suitable sample preparation technique, since particle size effects and matrix interference could be minimised, obtaining better linearity on the analytical calibration curves (r²), and more accurate and more precise results for bauxite analysis.     

辽东－吉南地区早元古代硼镁石型硼矿床地质特征及矿床成因

通过对辽东－吉南硼矿床地质特征、矿床地球化学及Ｏ、Ｃ、Ｂ同位素特征的研究，结合数学地质方法分析认为辽东－吉南地区早元古代硼矿的成矿作用可分为沉积成岩成矿和变质－混合岩化改造成矿这两个主要成矿期。矿床成因类型为沉积变质改造型