梭梭井银铅矿床银的赋存状态及其与回收率的关系

该矿床中银品位可达数千g/t.工业矿物为方铅矿、黄铜矿、银黝铜矿、螺状硫银矿—辉银矿、硫铜银矿等.本文在研究银的赋存状态、粒度和分布特征的基础上,探讨了银回收的有效途径.     

The Influence of CO on the Carbon Isotopic Composition of CH4 in Closed Pyrolysis Experiment With Coal

A low-mature coal (R_o=0.4%, from the Manjia'er depression, Tarim Basin, China) was subjected to closed system pyrolysis, in sealed gold tubes, under isothermal temperature conditions. The carbon isotopic compositions of the pyrolyst fractions (hydrocarbon, CO₂, CO, etc.) at two temperature points (350°C and 550°C) were measured. The results showed that {ie359-1} value is generally heavier at 350°C than that at 550°C, because the high abundance of CO generated at low temperature would greatly influence {ie359-2} value, and the retention time of CO in gas chromatograph is close to that of CH₄. But CO is formed through chemical reaction of the oxygen-containing functional group −C=O, e.g. lactones, ketones, ether, etc. at low temperature, while CO₂ comes mainly from decarboxylization. The carbon isotopic composition of coal gas from Lanzhou Coal Gas Works was definitely different from that of thermally pyrolysed products from coal. The {ie359-3} value of coal gas was abnormally heavier than {ie359-4}. At the same time, the reversed sequence ({ie359-5}) of {ie359-6} and {ie359-7} happened. The bond energy of free ions generally decides the sequence of generation of hydrocarbon fractions according to the chemical structure, whereas the stability of pyrolysate fractions and their carbon isotope fractionation are affected by the C−C bond energy. This study was supported by the National Basic Research (973) Program of China (No. 2001CB209102).     

四川呷村VHMS矿床：从矿石化学分析到地球化学模型

中国四川呷村矿床是一个典型的含金富银多金属VHMS矿床，其主要成矿金属元素Cu,Zn,Pb,Ag,Au丰度型式均呈非正态分布，多由两重或多重母体构成，揭示矿床经历了两次以上的成矿作用过程。成矿金属元素总体上集中于块状矿带，但贱金属Cu,Zn,Pb没有明显的下部富Cu Zn、上部富Pb Zn的分带，贵金属Ag、Au没有显示明显的层位优选性。矿床构造恢复和化学结构图像显示，金属元素的空间分布和富集机制严格受海底凹陷盆地的基底张性断裂和热水喷口位置控制。至少有4条近SN走向的盆地基底断裂带构成海底下部热水流体的迁移－排泄通道和网脉状成矿带的容矿空间；近EW向断裂与4条SN向断裂的交汇部位，成为上排泄的热水流体在海底的主要喷口，控制了金属元素在海底凹地的空间分布。分别处于凹陷盆地东缘和西缘的热水喷口，因正地形地貌形态而形成山丘堆式矿体（mound-syle)，而处于凹陷盆地中心的热水喷口则积聚大量热水流体，构成卤水池，淀积席状块状矿体（sheet-style)。     

吉黑东部花岗岩类的稳定同位素组成

吉黑东部花岗岩类分布广泛，形成历史漫长，岩石类型齐全。按成因类型划分，以I型为主，A型次之，S型很少，M型极少。其稳定同位素组成独特，大多数岩体锶初始值低，氧同位素正常或低，铅同位素以低^204Pb和高^206Pb/^204Pb、^207Pb/^204Pb、^208Pb/^204Pb为主，钕初始值高，说明其基底岩石成熟度低，地幔物质混入量较多。这些特点明显区别于华北和华南的花岗岩。     

微分阳极溶出伏安法连续测定天然水中铜、铅、镉、锌

铜、铅、镉、锌等微量元素是环境样品的重要检测指标 ,它对水质评价、生态环境考查及环境污染监测等有重要意义。天然水中这些元素含量极低 ,需要高灵敏度的检测手段方能检测。笔者用微分阳极溶出伏安法连续测定天然水中铜、铅、镉、锌 ,取得了良好效果。1　试验部分　　仪器与试剂　ＦＤＳＶ - 1溶出伏安 ,三电极系统 ;ＬＺ3- 2 0 4函数记录仪 ;氮气纯度为 99.99% ;ＨＡＣ -ＮａＡＣ缓冲液 ;ＨｇＣ水溶液 2 .0× 1 0 -3ｍｏｌ/Ｌ ;ＧａＣｌ3水溶液 1 0 0ｍｇ/ｍＬ ;Ｃｕ、Ｐｂ、Ｃｄ、Ｚｎ标准储备液 ( 1 .0ｍｇ/ｍＬ)分别由四元素的光谱氧…