闪锌矿内的Cd元素对Fe,Zn元素的选择性替换特征  

Study on Selective Replacement Characteristics of Fe and Zn by Cd in Sphalerite

作　　者：邵平[1] 石得凤 资锋 Shao Ping;Shi Defeng;Zi Feng(402 Geological Prospecting Party,Changsha 410014,China;School of Resource Environment and Safety Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南省地质矿产勘查开发局四〇二队,湖南长沙410014 [2]湖南科技大学资源环境与安全工程学院,湖南湘潭411201

出　　处：《湖南科技大学学报（自然科学版）》2020年第2期27-32,共6页Journal of Hunan University of Science And Technology：Natural Science Edition

基　　金：湖南省教育厅项目资助(17C0633);湖南省自然科学基金资助项目(2017JJ3071)。

摘　　要：传统认为以类质同象形式进入闪锌矿的Cd元素替换的是Zn元素,但笔者统计发现,部分矿床闪锌矿内Cd,Zn之间呈显著的正相关关系,Cd,Fe之间则显示显著的负相关关系,说明Cd在闪锌矿内可对Zn,Fe进行选择性替换.温度是决定Cd选择替换Fe或者Zn的关键性因素.高温条件下,可能仅有少量Cd替换Zn元素进入闪锌矿;而在低温条件下,随着早先进入闪锌矿的Fe2+向八面体转移出溶,Cd2+便优先选择替换与之更为接近的Fe2+进入闪锌矿.成矿温度降低及压力增大、硫离子活度增强、pH值的降低等条件,均有利于闪锌矿中Cd元素的富集.Cd in sphalerite in the form of isomorphism replaces Zn was conventionally believed.But the fact was found that there is a significant positive correlation between Cd and Zn in sphalerite in some deposits,while there is a significant negative correlation between Cd and Fe.It indicated that Cd can replace Zn and Fe selectively in sphalerite.Temperature is the key factor in determining the choice of Cd to replace Fe or Zn.In high temperature conditions,a small amount of Cd may enter the sphalerite throw replace Zn;In low temperature conditions,with the Fe earlier entry into the octahedron,the Cd2+preferentially replaces the Fe2+which is closer to itself and enter into the sphalerite.The decreasing ore-forming temperature,increasing pressure,increasing sulfur ion activity and lowering pH value are beneficial to the enrichment of Cd in sphalerite.

关 键 词：闪锌矿 Cd元素 类质同象 选择性替换 

分 类 号：P574.2[天文地球—矿物学]