原子吸收分光光度法测定锌精矿中锌

选择Ｚｎ的非灵敏线,采用原子吸收分光光度法测定锌精矿中高含量锌。共存离子互不干扰,平均回收率为９９．８２％,对于锌精矿测定５次,其ＲＳＤ〈０．５％,该法所测结果与国家标准分析方法测定的结果相符,且较标准分析方法简便,快速,实用性强。     

粤东麻坑非硫化物型锌矿锌的赋存状态及成因讨论

麻坑锌矿位于粤东晚古生代梅州拗陷东北部、近南北向蕉岭向斜的西翼,含矿岩石为强风化浅绿色粘土岩、黑色锰土及黑土角砾岩,未见原生金属硫化物,因此,有关锌的赋存状态及矿床成因一直不明。本文通过系统的岩矿石样品光薄片、砂光片显微镜下鉴定、X射线粉晶衍射物相分析和电子探针成分分析,查明了锌矿物主要以异极矿形式存在,仅含极少量菱锌矿;本矿床氧化作用较为彻底,矿床成因属浅成非硫化物型锌矿的直接交代亚类。上述锌的赋存状态及矿床成因探讨对类似矿床的认识与勘查具重要意义。     

在我国首次发现的三种磷酸锌矿物

在广东某锰矿区的南部,笔者发现三种罕见的磷酸锌矿物——副磷锌矿、磷钙锌矿、三斜磷锌矿。这三种矿物在我国均属首次发现。笔者对这三种矿物作了物理性质、化学性质、晶体光学性质、晶体结构、红外吸收光谱、差热分析等方面的测试,所得数据与国外资料对比基本相同。但经多次测定,该副磷锌矿为二轴晶负光性而与丹纳氏矿物学描述不同。本文较详细地描述了这些矿物的光性特征。     

含钴试料中锌的极谱测定

用Ca-EDTA作Co的掩蔽剂，再以NaOH溶液解蔽Zn－EDTA络合物，示波极谱法测定含钴试料中Zn。方法用于分析质量分数w（Zn）为0．1％－3％的矿石样品，结果与王水溶解－原子吸收法测定结果相符。对样品进行精密度检验，相对标准偏差（RSD，n＝5）＜10％。     

铅锌资源供需形势分析及市场前景预测

从资源保证程度、找矿前景、冶炼原料和金属产品的生产与需求、市场价格的变化趋势等几个方面,对铅锌资源的国内外市场的供需形势进行分析,并对其未来5年的市场前景进行了初步的预测。     

Zinc mineral weathering as affected by plant roots

The re-vegetation of soils contaminated by potentially harmful metals is generally considered a suitable option to reduce the metal dispersion in surrounding environments. A continuous flow experiment was conducted to quantitatively assess the effect of Italian ryegrass (Lolium multiflorum Lam.) root activity on the weathering of smithsonite (ZnCO₃), a common Zn mineral. At the end of the experiment (10 days), the total amount of Zn released by smithsonite was increased by a factor of 2.25 in the presence of plants. This increase was due not only to plant uptake but also to the enhancement of the Zn release into leachates. The rate of Zn release from smithsonite to leachates was 2.9 × 10⁻⁴ μg g⁻¹ s⁻¹ and 1.5 × 10⁻⁴ μg g⁻¹ s⁻¹ in the presence and the absence of plants, respectively. The strong correlation (r = 0.95; p < 0.001) between concentrations of Zn and dissolved organic C (DOC) produced by the rhizosphere activity in leachates indicated that organic root exudates and secretions were closely involved in smithsonite weathering. Although the results are derived from laboratory study, and further in situ investigations over the long term are needed, they clearly highlighted that plants can enhance metal release into the environment by accelerating mineral weathering. Therefore, it is suggested that the ability of plants to alter metal phases in soils should be further taken into account when re-vegetation strategies are proposed for the rehabilitation of metal-polluted soils.     

交流示波极谱滴定锌的研究

本文提出了在pH9的0.10mol/L NH_3·H_2O-0.23mol/L NH_4Cl缓冲溶液中,用EDTMP滴定Zn,以Zn在交流示波极谱dE/dt-E曲线上切口消失直接指示终点。所研究的方法已用于测定一些铅锌矿和锌铝合金中的Zn,结果满意。Zn量分析范围为0.900—12.00mg,方法回收率为98.65—101.3％。对于含Zn xx％的试样分析10次相对标准偏差为0.26—1.27％。     

沉淀分离－火焰原子吸收光谱法连续测定锌精矿中杂质元素

利用Ｚｎ（ＯＨ）＿２的两性沉淀富集待测杂质元素，分离高含量Ｚｎ以排除干扰，用火焰原子吸收法测定其中的杂质元素含量。实验结果表明：分离后残留的Ｚｎ对Ｆｅ、Ｃｄ、Ｎｉ、Ｍｎ、Ａｇ的测定无干扰；各元素之间互不干扰。加标回收率为９３％～１０６％，对菱锌矿中几种杂质元素进行测定，结果与ＩＣＰ－ＡＥＳ法相符，各元素测定的相对标准偏差（ｎ＝１２）为４．１％～８．８％。     

黄姜皂素纤维渣的氯化锌热解特性

探讨氯化锌活化黄姜皂素纤维渣的机理, 应用TG-FTIR联用技术考察了黄姜皂素纤维渣的氯化锌热解特性.不同的配比、氛围及升温速率对热解均有影响.低温氧化有利于活性炭的形成, 但高温氧气的存在对炭体烧失较大; 氯化锌与原料的配比越高, 对原料的侵蚀性越强, 采取相应的活化温度较低; 升温速率越低越有利于原料中有机质蓄积热量热解, 相应的活化温度也越低; 红外光谱图也表示挥发分产物的出现与热重分析相符, 没有时间滞后现象.因此, 确定制备活性炭的初步工艺为先在300℃左右低温炭化, 再在保护气氛中(如N2) 500℃左右活化, 升温速率10K/min左右.工业生产条件下, 活化温度最高不宜超过650℃.      

热液矿床中锌的迁移、沉淀机制综述

硅酸盐熔体体系中,锌主要赋存于熔体相,部分以类质同象的形式进入铁、镁硅酸盐及铁的氧化物中;流体/熔体相分 离时,锌优先进入流体相;卤水/气相分离时,锌优先进入卤水相;成矿过程中,锌主要进入液相流体中迁移。在热液环境 下, ZnCl2 - nn （0≤n≤4） 络合物是迁移锌的最重要形式,其次游离Zn2+,Zn2+-SO2 -4 络合物,Zn2+OH-络合物,在一定条件下对锌的运移也非常重要,但能与锌络合的其它潜在无机配体,如HS-,CO32-,NH3,F-,Br-, S2 -x 及S2O2 - 3 等,则意义不大。富有机质低温（<200℃） 条件下,部分有机质对锌的迁移也具有重要作用,如,羧酸、氨基酸及腐殖酸,其中羧酸意义最大。在Zn成矿过程中,岩浆-热液Zn矿床矿化可划分为三个阶段,早期岩浆房去气阶段,期后热液阶段,以及晚期岩浆房去气阶段。层控Zn矿床流体主要为盆地卤水,矿化机制主要为伸展背景下的海底热液对流,或者挤压环境下,构造挤压与重力的联合驱动,促使流体向盆地边缘迁移成矿。锌矿物的沉淀主要受热液组成、温度、压力、pH以及Eh等因素控制,地质过程中,围岩蚀变、沸腾作用以及流体混合作用等宏观过程促使上述物理化学因素发生变化,从而制约着锌的沉淀。     

低品位氧化锌矿硫化-胺法分选试验

随着大量易选硫化锌矿资源的不断消耗,细粒难选低品位氧化锌矿逐渐成为重要原料。本文针对云南兰坪大量低品位氧化锌矿石,其含锌6.52%,锌的氧化率94.62%,采用硫化-胺法浮选工艺流程,研究了磨矿细度、药剂种类、药剂用量等因素对锌浮选过程的影响。在磨矿细度为-0.074mm 90%时采用一次粗选两次扫选三次精选的闭路流程,获得锌精矿产率9.70%,Zn品位44.09%,Zn回收率66.35%较好指标。本研究对我国低品位氧化锌矿资源的开发利用具有重要借鉴意义。     

水杨基荧光酮与锌显色反应及应用

在ｐＨ为９５的ＮＨ４Ｃｌ＿ＮＨ３·Ｈ２Ｏ介质中，溴化十二烷基二甲基苄铵存在下，Ｚｎ（Ⅱ）与水杨基荧光酮形成１∶２的紫红色配合物，其最大吸收波长为５７０ｎｍ，表观摩尔吸光系数为８７１×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，Ｚｎ（Ⅱ）的质量浓度为０～０３６ｍｇ／Ｌ时符合比尔定律。拟定的新方法应用于矿样中微量锌的测定，结果满意     

Zn同位素分析方法及其地质应用

介绍了Zn同位素组成的表示方法及其化学分离与质谱测定方法,论述了Zn同位素在陨石、沉积物和沉积岩、火成岩、矿床和海水以及生物样品中的组成特征,以及生物有机作用、物理-化学作用对Zn同位素分馏的影响,阐述了Zn同位素在陨石和宇宙化学、古海洋学、全球气候变化研究中的应用现状与前景.     

Zinc isotope fractionation under vaporization processes and in aqueous solutions

Equilibrium Zn isotope fractionation was investigated using first-principles quantum chemistry methods at the B3LYP/6-311G* level. The volume variable cluster model method was used to calculate isotope fractionation factors of sphalerite, smithsonite, calcite, anorthite, forsterite, and enstatite. The water-droplet method was used to calculate Zn isotope fractionation factors of Zn²⁺-bearing aqueous species; their reduced partition function ratio factors decreased in the order \(\left[ {{\text{Zn}}\left( {{\text{H}}_{2} {\text{O}}} \right)_{6} } \right]^{2 + } > \left[ {{\text{ZnCl}}\left( {{\text{H}}_{2} {\text{O}}} \right)_{5} } \right]^{ + } > \left[ {{\text{ZnCl}}_{2} \left( {{\text{H}}_{2} {\text{O}}} \right)_{4} } \right] > \left[ {{\text{ZnCl}}_{3} \left( {{\text{H}}_{2} {\text{O}}} \right)_{2} } \right]^{ - } > {\text{ZnCl}}_{4} ]^{2 - }\). Gaseous ZnCl₂ was also calculated for vaporization processes. Kinetic isotope fractionation of diffusional processes in a vacuum was directly calculated using formulas provided by Richter and co-workers. Our calculations show that in addition to the kinetic isotope effect of diffusional processes, equilibrium isotope fractionation also contributed nontrivially to observed Zn isotope fractionation of vaporization processes. The calculated net Zn isotope fractionation of vaporization processes was 7–7.5‰, with ZnCl₂ as the gaseous species. This matches experimental observations of the range of Zn isotope distribution of lunar samples. Therefore, vaporization processes may be the cause of the large distribution of Zn isotope signals found on the Moon. However, we cannot further distinguish the origin of such vaporization processes; it might be due either to igneous rock melting in meteorite bombardments or to a giant impact event. Furthermore, isotope fractionation between Zn-bearing aqueous species and minerals that we have provided helps explain Zn isotope data in the fields of ore deposits and petrology.     

凡口铅锌矿床同位素地球化学证据

对凡口铅锌矿床不同成矿阶段进行矿物包裹体温度、硫和铅同位素测定，获得成矿第Ⅰ阶段温度为300±50℃，第Ⅱ、Ⅲ阶段温度为250±50℃；并获得矿床硫化物的S同位素组成为2.1‰～26.5‰，具有δ34SPy＞δ34SSp＞δ34SGn；第Ⅰ阶段硫化物的硫同位素组成随赋存层位由老到新硫同位素有逐渐减小趋势；第Ⅱ阶段硫化物的δ34S为14.3‰～23.8‰；第Ⅲ阶段硫化物的δ34S为5.7％~15.7‰，具有从早阶段至晚阶段硫同位素组成变化范围从大至小的减小趋势。分析获得68件铅同位素数据，其中硫化物的206Pb/204Pb比值为18.023～18.847；207Pb/204Pb比值为15.700～15.820；208Pb/204Pb比值为38.056～39.796。灰岩全岩的206Pb/204Pb比值为18.230～18.860；207Pb/204Pb比值为15.640～16.000；208Pb/204Pb比值为38.714～39.960。辉绿岩的206Pb/204Pb比值为18.570～18.650；207Pb/204Pb比值为15.260～15.620；208Pb/204Pb比值为38.650～38.960。第Ⅰ阶段δ34OH2O为13.3‰~13.1‰，δD为－50.2‰～－61.5‰；第Ⅱ阶段δ18OH2O为－2.4‰～＋10.8‰，δD为－50.2‰～－63.2‰；第Ⅲ阶段δ18OH2O为－4.9‰～－14.3‰，δD为－59.0‰～－61.0‰。     

岩石中铅和锌的分离与测定

将KHSO4加入在小体积(1mL)试液中,以K2SO4·PbSO4复盐形式沉淀分离Pb,再用NH4Ac溶液热提Pb,1mgPb的平均回收率为100.66%;滤液再蒸至1mL小体积,加入NaCl NaOH小体积两次沉淀分离Fe、Ti、Mn等干扰元素,存在于滤液中的Zn平均回收率为100.5%。分离所得的含Pb2+和Zn2+的溶液用EDTA分别进行滴定,测定范围(质量分数,w)由0.5%下延至0.01%;测定结果与极谱法相一致;精密度(RSD,n=10)试验Pb为2.6%,Zn为1.4%。     

Zinc isotopic behavior of mafic rocks during continental deep subduction

Zinc isotopes may act as a new tool of tracking recycling of crustal materials that causes compositional heterogeneity of the mantle.This application relies on an investigation of Zn isotopic behaviors during slab subduction.In this study,we re port Zn isotopic compositions for a suite of metabasalts(greenschists,amphibolite s,and coesitebearing eclogites) from the Dabie Orogen(China),which were formed via the subduction of mafic rocks into different depths and up to 200 km.Three out of eight greenschists are characterized by lighter δ~(66)Zn_(JMC-Lyon)(0.10‰-0.16‰) than those of global basalts(0.28‰± 0.05‰),which may be caused by crustal assimilation of the protoliths by sedimentary rocks due to their extremely high ~(87)Sr/~(86)Sr(up to 0.7130) and low sNd values(down to-12.3).The remaining greenschists have relatively low ~(87)Sr/~(86)Sr and their δ~(66)Zn values(0.21‰-0.38‰) overlap the ranges of amphibolites(0.18‰-0.32‰) and coesite-bearing eclogites(0.18‰-0.36‰).There is no correlation between δ~(66)Zn and sensitive indicators of dehydration(Rb/TiO_2 Ba/Yb, and H_2 O~+), suggesting that no detectable Zn isotope fractionation has occurred during the deep subduction of mafic rocks even into 200 km,which is attributed to the limited loss of Zn during prograde metamorphism and dehydration.Thus,Zn isotopic compositions of the deeply subducted mafic rocks are inherited from their protoliths.Considering that these metamorphosed rocks have higher δ~(66)Zn than that of the mantle value by up to 0.2‰, the recycled/subducted mafic crust can incorporate isotopically heavy Zn into the mantle.The subducted slabs may partially melt and generate a metasomatized mantle,resulting in changes of Zn isotopic composition of the hybridized mantle as have been observed in some mantle xenoliths and ba saltic lavas.     

锌同位素地球化学及应用研究进展

随着化学纯化技术的提高及质谱仪的开发与应用,锌同位素已成为近年来非传统稳定同位素地球化学的一个研究热点,人们对锌同位素地球化学的认识随着研究的深入有了极大提高。本文对锌同位素地球化学进行了全面的综述,追踪了锌同位素在地学领域最新的研究进展。目前,锌同位素已被广泛应用在天体化学、环境地球化学、古海洋、古环境重建以及深部碳循环等诸多地球科学及环境科学研究领域,展现出巨大的应用潜力。各领域的研究成果为推进锌同位素地球化学的发展做出了巨大贡献。     

二溴羟基苯基荧光酮光度法测定锌

在ｐＨ１１４的Ｎａ２ＨＰＯ４ＮａＯＨ缓冲介质中,表面活性剂溴化十六烷基吡啶（ＣＰＢ）及ＴｒｉｔｏｎＸ１００存在下,锌与二溴羟基苯基荧光酮发生显色反应,生成的络合物最大吸收波长在６１０ｎｍ处,摩尔吸光系数１７８×１０５Ｌ·ｍｏｌ－１·ｃｍ－１。ＮａＰＯ３的存在可提高方法的灵敏度与选择性。比尔定律范围是０～３２０μｇ／Ｌ,可不经分离直接测定硫铁矿中锌。对硫铁矿中ｗ（Ｚｎ）为００２％或０４％的样品进行６次平行测定,其ＲＳＤ为１６３％～５３％。