Li-Sr-Nd isotope signatures of the plume and cratonic lithospheric mantle beneath the margin of the rifted Tanzanian craton (Labait)

Lithium concentrations and isotopic compositions of olivine and ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd of coexisting clinopyroxene from peridotite xenoliths from the Quaternary Labait volcano, Tanzania, document the influence of rift-related metasomatism on the ancient cratonic mantle. Olivines show negative correlations between Fo content and both δ⁷Li and Li concentrations. Olivines in iron-rich peridotites (Fo_85–87) have high Li concentrations (3.2–4.8 ppm) and heavy δ⁷Li (+5.2 to +6.6). In contrast, olivines in ancient, refractory peridotites have lower Li concentrations (∼2 ppm) and relatively light δ⁷Li (+2.6 to +3.5). This reflects mixing between ancient, refractory cratonic lithosphere and asthenosphere-derived rift magmas. A uniquely fertile, deformed, high-temperature garnet lherzolite, interpreted to be from the base of the lithosphere, has a ⁸⁷Sr/⁸⁶Sr of 0.7029 and ¹⁴³Nd/¹⁴⁴Nd of 0.51286, similar to HIMU oceanic basalts. It provides the best estimate of the Sr–Nd isotope composition of the upwelling mantle (i.e., plume, sensu lato) underlying this portion of the East African Rift, and is slightly less radiogenic compared to previous estimates of the plume that were based on rift basalts. Although elevated δ⁷Li are not exclusive to HIMU source regions, the data collectively indicate that the plume beneath Labait has HIMU characteristics in Sr, Nd and Li isotope composition. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

青海省盐湖钾、镁、锂盐资源开发利用探讨

论述了青海省盐湖资源中钾、镁、锂盐工业的资源状况、生产现状以及开发利用的迫切性 ,并对钾、镁、锂盐资源的综合利用进行了探讨     

Chlorine-36 in groundwater of the United States: empirical data

Natural production of the radionuclide chlorine-36 (³⁶Cl) has provided a valuable tracer for groundwater studies. The nuclear industry, especially the testing of thermonuclear weapons, has also produced large amounts of ³⁶Cl that can be detected in many samples of groundwater. In order to be most useful in hydrologic studies, the natural production prior to 1952 should be distinguished from more recent artificial sources. The object of this study was to reconstruct the probable preanthropogenic levels of ³⁶Cl in groundwater in the United States. Although significant local variations exist, they are superimposed on a broad regional pattern of ³⁶Cl/Cl ratios in the United States. Owing to the influence of atmospherically transported ocean salt, natural ratios of ³⁶Cl/total Cl are lowest near the coast and increase to a maximum in the central Rocky Mountains of the United States. Electronic Publication     

铅—试铁灵络合物吸附波及溴化十六烷基三甲基铵增敏效应的研究

在０３０ｍｏｌ／ＬＨＡｃ介质中，Ｐｂ（Ⅱ）与７＿碘＿８＿羟基喹啉＿５＿磺酸（试铁灵，Ｆｅｒｏｎ）的络合物于－０５４Ｖ（ｖｓ．ＳＣＥ）产生一尖锐的极谱波，加入溴化十六烷基三甲基铵（ＣＴＭＡＢ）显著增敏，可使极谱波增高约４倍。峰电流与Ｐｂ（Ⅱ）浓度在９６×１０－９～４８×１０－６ｍｏｌ／Ｌ呈良好的线性关系，检出限为４８×１０－９ｍｏｌ／Ｌ。用多种电化学方法研究了该极谱波的性质及电极反应机理表明，络合物组成比为ｎＰｂ（Ⅱ）∶ｎＦｅｒｏｎ＝１∶１，极谱波为吸附波，峰电流由中心离子Ｐｂ（Ⅱ）还原产生，电子转移数为２。试验了多种离子对峰电流的影响，拟定的方法用于矿样分析，结果与原结果相符。     

Li2O—B2O3功能材料体系研究概述

本文介绍了碱金属硼酸盐的一些基本知识，主要回顾了其中Ｌｉ２Ｏ—Ｂ２Ｏ３体系的研究历史，讨论了该体系结构与性质的关系并总结了Ｌｉ２Ｏ－Ｂ２Ｏ３晶态及非晶态物质作为新型功能材料的研究进展。     

卤水提锂的萃取体系概述

介绍了国内外萃取法在含锂溶液,尤其在卤水中提取锂的部分研究进展情况,重点对各种萃取体系的机理和特点进行了说明,并对今后我国盐湖卤水萃取法提锂研究的方向进行了总结。     

长江流域河水和悬浮物的锂同位素地球化学研究

深入理解流域侵蚀过程中的锂同位素分馏对于运用锂同位素来示踪化学循环和气候变化是十分必要的。研究集中在长江干流和主要支流的水体和悬浮物的锂及锂同位素组成。长江流域水体的锂及锂同位素组成（δ⁷Li）分别为150~4 570 nmol/L和+7.6‰~+28.1‰,两者沿上游至下游的变化趋势相反。悬浮物锂同位素组成（δ⁷Li）变化比较稳定,分别为41~92 μg/g和-4.7‰~+0.7‰,而且总是低于相应水体的锂同位素组成。悬浮物和流体之间的锂同位素分馏系数在0.977和0.992之间,与悬浮物的量及组成存在明显相关性,反映了粘土矿物的吸附和化学风化的程度。锂含量与锂同位素组成之间良好的负相关性表明流域水体的锂来自2个端元混合：其一可能是蒸发盐岩,并伴有深部热泉水;其二可能是硅酸岩。     

Extraction of Lithium from Salt Lake Brine using N523-TBP Mixture System

In this work,problems encountered by tri-butyl phosphate( TBP) in the industrialization of lithium extraction from salt lake brine were discussed in detail. The behavior of N,N-bi-( 2-ethylhexyl) acetamide( N523) during lithium extraction was investigated,and its disadvantages were analyzed in the view of practical application. An N523-TBP mixture extraction system was proposed to alleviate or avoid the defects that N523 and TBP met when they were used separately. The optimal composition of this mixture extraction system was determined to be 20% N523-30% TBP-50% kerosene.The effects of brine acidity,Fe/Li molarity ratio,phase ratio and chloride ion concentration on lithium extraction efficiency were discussed. The operation conditions in single-stage extraction were optimized as brine acidity = 0. 05 mol/L,Fe/Li molarity ratio = 1. 3,and phase ratio = 2. The high concentration of chloride ions in brine was beneficial for the extraction of lithium. The structure of the extracted complex was proposed as( LiFeCl_4·n N523·m TBP)·( 2-n) N523·( 2-m) TBP( m + n = 2) by chemical analysis and slope-fitting methods. The extraction thermodynamic functions were calculated preliminarily,and the results suggested that the extraction process was an exothermic( ΔH 0) and spontaneous( ΔG 0) reaction,and the degree of disorder increased( ΔS 0) during the extraction process. This work will give some guidance to the lithium industry of Qinghai in both the fundamental theory and practical application.     

锡－盐酸－溴化十四烷基三甲铵极谱催化波体系及其应用

在０．００２％溴化十四烷基三甲铵（ＴＴＭＡＢ）－２０％ＨＣＩ体系中，Ｓｎ有一灵敏的吸附波，峰电位在－０．４７Ｖ（ｖｓ．Ａｇ／ＡｇＣｌ），线性范围２～１０００ｎｇ／ｍｌ。体系可用于岩石、土壤样品中微量Ｓｎ测定；机理研究表明，溴化一四烷基三甲铵通过诱导吸附ＳｎＣｌ提高测定的灵敏度。     

A neutron diffraction study of alkali cation migration in montmorillonites

Neutron powder diffraction measurements on lithium and cesium saturated montmorillonite samples before and after heat treatment at 300°C are studied, in order to undertake a complete refinement of crystal structure and unravel the migration mechanism for the interlayer cations of Li or Cs. Rietveld analysis of the corresponding diffraction patterns finds that montmorillonite crystallizes in the C2/m space group with unit cell dimensions consistent with the size of the specific interlayer cation. We show that thermal treatment affects the two types of samples in a different way. This is with respect to their unit cell dimensions and the migration of Li from the 2b to the 2c clay lattice site, in constrast to the Cs positioning which remains effectively unchanged.