深海锰结核的化学和放射化学研究

学位：理学硕士院系专业：海洋与环境学院海洋学系_海洋化学学号：YL000082

深海锰结核中元素的扩散及深度分布特征的研究

本文用电感耦合等离子体原子发射光谱法(ICP—AES)测量了从中太平洋北部海底采集的锰结核样品的元素组成并用铀系测年法测定了它们的生长速率,结果表明,锰结核中元素的深度分布有随深度增加、减少和起伏不定三种特征,这些锰结核内部的元素组成的变化,一般被认为是由于锰结核中元素的扩散和迁移以及锰结核的不均匀性所致。 本文用扩散模型解释了锰结核中元素含量向内增加的分布,据此模型计算,锰结核中Ni、V和Zn的有效扩散系数为10~(-9)cm~2/a数量级——小于对放射性核素所报道的数值

RELATIONSHIP BETWEEN ACCRETION OF MANGANESE NODULES AND SEDIMENTARY ENVIRONMENTS

本文收集了48组世界大洋各种沉积环境锰结核化学组成和生长速率数据并计算了它们的铁锰通量;讨论了不同环境的锰结核的铁锰含量之间的关系,以及锰通量与铁通量、Mn/Fe比的相关性;导出了由锰结核锰铁含量计算生长速率的经验关系;从本质上揭示了锰结核化学组成、生长速率与沉积环境的内在联系,为探讨锰结核形成机理提供了有力的依据. 【英文摘要】 48 data sets on the major chemical compositions (Mn and Fe concentrations) and growth rates of manganese nodules from different sedimentary environments of the oceans have been collected and their fluxes of manganese and iron have been calculated. It has been shown that although the chemical compositions and growth rates of manganese nodules from different areas of the oceans are largely different (Mn: 11.3-44.9%; Fe: 0.724-20.5%; growth rates: 0.80-200mm / 106yr) , there are small differences in Fe fluxes ..

The Separation of U, Th And the Determination of U-Series Age in the Geological Carbonate Samples

本文报道了我们测定两个国内铀系碳酸盐标准样的结果。叙述了所用的α能谱技术和铀、钍化学分离流程。结果表明,我们所测得的铀、钍α谱的能量分辨率为31—40keV,铀—钍的互相分离比较完全;获得的各项数据与十个实验室数据的平均值基本一致。 【英文摘要】 This laboratory is involved in Uranium-Series Intercomparison Project in China, for standardizing the 232U concentration in the 232U-228Th spike solution and determining various U,Th isotope ratios of two carbonate samples from which their U-series ages could be calculated. Various data obtained by us were well agreeable with the mean values recorded by all the laboratories concerned.The present paper describes the alpha spectrometry technique used for determining U, Th isotopes and U, Th chemical separatio..

The Proxy of Seabed Tectonic Process: CaCO_3/Fe_2O_3 and MgCO_3/Fe_2O_3 Ratios in Polymetallic Nodules

研究了中太平洋 3个多金属结核中共 5个侧面CaCO3 /Fe2 O3 和MgCO3 /Fe2 O3 比值的深度分布 .根据CaCO3 的热力学性质 ,我们认为结核中的CaCO3 /Fe2 O3 比值与沉积物中的CaCO3 保存量类似 ,与古水深之间存在着负相关关系 .结核中由表及里 ,CaCO3 /Fe2 O3 比值逐渐增大 ,说明结核所处海域 ,即中太平洋海盆的水深逐渐增大 ,这在一定程度上也反映了中太平洋海盆的下降 ,因而结核中的CaCO3 /Fe2 O3 比值也许可以作为海底构造运动的指示物 .而MgCO3 /Fe2 O3 比值与其有着良好的一致性 ,说明其与CaCO3 /Fe2 O3 比值一样 ,也可以作为海底构造运动的指示物 【英文摘要】 CaCO 3/Fe 2O 3 and MgCO 3/Fe 2O 3 ratios' depth profiles of 5 sides in 3 polymetallic nodules from central Pacific Ocean were studied. Basing on the thermodynamics of CaCO 3, we find that the CaCO 3/Fe 2O 3 ratios in nodules, like the preservation of CaCO 3 in the sediment, show the negative correlation with paleo-depth of the ocean. The inward increase of CaCO 3/Fe 2O 3 ratios in nodules reflects the gradually increasing of depth of central Pacific Ocean basin, where these nodules locating. T...中国大洋矿产资源研究开发协会“九五”国家专项资助项目 (DY95 0 2 15

A NEW METHOD FOR SEPARATION AND DETERMINATION OF U AND Th IN DEEP-SEA MANGANESE NODULES

A new and simple method for separation and determination of U and Th in manganese nodules has been developed. The results show that the addition of NH4NO3 to the dilute HNO3 medium increases the selectivity of anion-exchange separation of U and Th. The simple procedure and high recoveries of the method make it valuable to the analyses of U and Th in manganese nodule

深海锰结核的放射化学研究

本文采用单柱的阴离子交换技术和α能谱测定法测量了取自中太平洋北部海域的深海锰结核样品中铀、钍同位素的放射性。结果表明,锰结核表层的~(231)Pa和~(230)Th放射性比它们的母体高2—3个数量级,并且由表及里换指数关系衰减。锰结核的生长速率测定为0.8—7.4mm/10~6a,这与锰结核本身的Fe、Mn含量及下覆沉积物的类型有关。锰结核的翻转时间测定为10~4—10~5年数量级

Anion-exchange Separation and Determination of Uranium and Thorium in Oceanic Samples

关于铀、钍的分离与测定方法国内外已有不少报道,但分离流程一般都比较冗繁,且回收率低,对海洋样品尤其如此。本文在已建立的离子交换分离铀、钍流程的基础上,采用柱柱法进行海洋样品中铀、钍的分离并用α能谱法测定铀、钍的同位素含 【英文摘要】 A simplified method has been developed to separate and estimate the activities of uranium and thorium isotopes in oceanic samples. Uranium and thorium can be simultaneously separated from the sample through an anion exchange column in NH4NO3-HNO3 medium and separately estimated by means of alpha spectrometry. Seven samples including sea water, sediments, manganese nodule, coral and fresh oyster, were collected and practised with this method, It was demonstrated that the procedure is simple, efficient, and c..

深海锰结核中铀、钍分离与测定新方法的研

本文研究了铀和钍在HNO_3-NH_4NO_3体系中的阴离子交换分离,提出了仅用一根离子交换柱就能从深海锰结核这种复杂体系中有效地分离出微量的放射化学纯的铀和钍的新方法。结果表明HNO_3-NH_4NO_3体系阴离子交换分离铀和钍具有较高的选择性,而且体系的酸度下降或硝酸铵浓度提高均有利于铀或钍在树脂相的吸附。该分离方法可定量回收锰结核样品中的铀和钍,且流程简短、操作方便,特别适用于成批的海洋环境样品的分析

Studies on Chemical Status of Manganese Nodules by a Selectively-Leaching Technique

用1.5 mol/l HOAc,1.5 mol/l HOAc-1.0 mol/l NH_2OH·HCl(v/v1:1),6 mol/l HCl 和 HF-HCl 作沥取剂,选择沥取锰结核的不同地球化学相中的元素,并用等离子体原子发射光谱法分析了各相的化学组成,用放化技术测量了各相的铀系核素。结果表明,碳酸盐、吸附态元素及大部分U同位素存在于HOAc 相,Fe-Mn 氧化物矿物,Cu,Co,Ni,V 等元素及~(226)Ra,~(210)Pb存在于 NH_2OH·HCl 相,HCl 相由富Ti 和Th 的矿物及Fe 的稳定矿物(如针铁矿)组成,而 HF-HCl 相则是富 Si 和Al的铝硅酸盐,包括粘土矿物和碎屑矿物。 【英文摘要】 A new method has been developed to leach sequentially and selectively the elements in different geochemieal phases of manganese nodules by using 1.5 mol/l HOAc, 1.5 mol/l HOAc-1.0 mol/l NH2OH·HCl,6 mol/1 HC1, and HP-HC1 as the leaching agents and the chemical compositions of each phase has Leen analysed by ICP-AES and the activities of U-series nuclides by radiochemical technique. It is shown that Ca-rich carbonate such as calicite and the absorbed forms of elements exist in the HOAc phase; the NH2OH·HCl ph..