表生条件下红铊矿氧化溶解动力学初步研究  

A KINETIC STUDY ONOXIDATION OF LORANDITE IN UNDERHYPERGENE CONDITION

作　　者：李德先[1] 张欢[2] 朱咏煊[2] 郁云妹[2] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵州贵阳550002

出　　处：《矿物学报》2007年第3期330-334,共5页Acta Mineralogica Sinica

基　　金：国家自然科学基金(40373041)

摘　　要：红铊矿是一种含有有毒元素铊和砷的矿物,在氧化和酸性的介质中很容易被氧化和分解,对环境造成污染。本文的目的是研究红铊矿在表生条件下的氧化溶解速率及其影响因素,为铊的环境污染治理提供理论依据。根据一系列溶解实验,获得如下主要结论:①红铊矿的溶解受温度、氧化剂浓度及氧化剂中阴离子种类的影响。随着温度的升高,红铊矿的溶解速率逐渐增高;随着氧化剂浓度的升高,红铊矿的溶解速率逐渐降低;对氧化剂中Cl-和SO42-离子的比较表明,Cl-离子存在更有利于红铊矿的溶解。②高铁浓度(10-3mol/L)下,红铊矿的溶解速率降低,归因于红铊矿表面形成了一层纳米级的铁硫化合物的膜,阻止了红铊矿进一步溶解。③红铊矿每平方米暴露面积24 h溶解出来的铊总量接近0.01 mg,表明酸性矿水条件下红铊矿的溶解是贵州省兴仁县滥木厂地区铊污染的重要来源。Lorandite is one of the minerals containing toxic elements of thallium and arsenic, which is easily oxidized and decomposed under oxidative and acidic conditions. This paper deals with the oxidation-dissolution rate of lorandite and the affecting factors, This will offer a theoretical basis for thallium environment pollution. From a series of oxidation-dissolution experiments on lorandite, some conclusions can be drawn as follows： （ 1 ）The rate of oxidation of lorandite was affected by the temperature of solution, the concentrations of oxidant and kinds of anion in the oxidant. The rate of oxidation of lorandite increased or decreased with increasing temperature and concentrations of oxidant, respectively. The Clˉ1canbe more propitious to the oxidation-dissolution of lorandite than SO4^2-. （2）The rate of oxidation-dissolution of lorandite decreased when the concentrations of iron were high. That is because the film will be formed on the surface of lorandite （about several urn） from sulfur and iron, and this film will prevent lorandite from dissolution. （3）The total thallium contents of soluble lorandite in 24 hours every square meter are 0.01mg. This shows that the oxidation-dissolution of lorandite in acid mine water is one of the important factors leading to thallium pollution in the Lanmuchang region, Xinren County, Guizhou Province.

关 键 词：红铊矿 氧化速率 环境污染 

分 类 号：P578.2[天文地球—矿物学] P599[天文地球—地质学]