简介概要

有色冶炼废渣的矿物学特征与环境活性

来源期刊:中南大学学报(自然科学版)2007年第6期

论文作者:郭朝晖 程义 柴立元 宋杰

文章页码:1100 - 1105

关键词:有色冶炼废渣;重金属;矿物相;BCR法;环境活性

Key words:nonferrous slag; heavy metal; mineral phase; three-stage BCR sequential extraction procedure; environmental availability

摘    要:通过扫描电子显微镜与X射线衍射仪分析、BCR法三步连续提取及元素化学分析,对某有色冶炼废渣中重金属的赋存状态、环境活性及其释放机理进行研究。研究结果表明:废渣中主要有价金属为Fe,Zn,Cu,Pb,Ag和In等,主要毒害元素为Pb,Cd和As等。废渣矿物相中Fe主要以单质铁、铁的氧化物和硫化亚铁存在,Zn主要以闪锌矿存在,Pb主要以方铅矿存在,Cu和Cd主要以硫化矿物等形式存在;Ag和In则很可能以类质同相镶嵌在闪锌矿晶格中;废渣中Zn,Cd,Cu和Pb主要以残渣态为主;酸可提取态含量相对较低,而可还原态和可氧化态含量相对较高;在我国南方地区,酸沉降、微生物作用及原电池效应共同影响废渣中重金属的溶出,为生物浸出废渣中有价金属,实现其资源化和无害化提供了理论依据。

Abstract: The geochemical distribution, environmental availability and releasing mechanisms of heavy metals from the non-ferrous slag were studied through scanning electron microscope analysis, X-ray diffraction analysis, three-stage BCR sequential extraction procedure and metals element chemical analysis. The results show that the slag mainly includes valuable metals of iron, zinc, copper, lead, silver, and indium, and toxic metals of lead, cadmium, and arsenic, respectively. The mineralogical components of iron in slag mainly contain single iron, iron of oxides and sulfide, the component of zinc is sphalerite, of lead is galena, and that of copper and cadmium is sulfide, respectively. But, the mineralogical components of silver and indium in slag are opaque and probably stud in the crystal lattice of sphalerite with isomorphism. The speciation of zinc, cadmium, copper, and lead in the slag exists mainly in residual forms. The percentage of acidic extractable forms of metals in slag is low while that of reducible and oxidizable forms is high, respectively. In the South of China, the releasing potential of heavy metals from the slag is significantly affected by acid deposition, microbial effect and galvanic effect, and the recycling and toxicity reduction of nonferrous slag through bioleaching is evaluated.

基金信息:国家自然科学基金资助项目
中南大学博士后基金资助项目



详情信息展示

有色冶炼废渣的矿物学特征与环境活性

郭朝晖1, 2,程  义2,柴立元2,宋  杰2

(1. 中南大学 资源加工与生物工程学院,湖南 长沙,410083;

2. 中南大学 冶金科学与工程学院,湖南 长沙,410083)

摘  要:通过扫描电子显微镜与X射线衍射仪分析、BCR法三步连续提取及元素化学分析,对某有色冶炼废渣中重金属的赋存状态、环境活性及其释放机理进行研究。研究结果表明:废渣中主要有价金属为Fe,Zn,Cu,Pb,Ag和In等,主要毒害元素为Pb,Cd和As等。废渣矿物相中Fe主要以单质铁、铁的氧化物和硫化亚铁存在,Zn主要以闪锌矿存在,Pb主要以方铅矿存在,Cu和Cd主要以硫化矿物等形式存在;Ag和In则很可能以类质同相镶嵌在闪锌矿晶格中;废渣中Zn,Cd,Cu和Pb主要以残渣态为主;酸可提取态含量相对较低,而可还原态和可氧化态含量相对较高;在我国南方地区,酸沉降、微生物作用及原电池效应共同影响废渣中重金属的溶出,为生物浸出废渣中有价金属,实现其资源化和无害化提供了理论依据。

关键词:有色冶炼废渣;重金属;矿物相;BCR法;环境活性

中图分类号:X142; X705         文献标识码:A         文章编号:1672-7207(2007)06-1100-06

Mineralogical characteristics and environmental availability of

non-ferrous slag

GUO Zhao-hui1, 2, CHENG Yi2, CHAI Li-yuan2, SONG Jie2

(1. School of Resources Procesing and Bioengineering, Central South University, Changsha 410083, China;

2. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China)

Abstract: The geochemical distribution, environmental availability and releasing mechanisms of heavy metals from the non-ferrous slag were studied through scanning electron microscope analysis, X-ray diffraction analysis, three-stage BCR sequential extraction procedure and metals element chemical analysis. The results show that the slag mainly includes valuable metals of iron, zinc, copper, lead, silver, and indium, and toxic metals of lead, cadmium, and arsenic, respectively. The mineralogical components of iron in slag mainly contain single iron, iron of oxides and sulfide, the component of zinc is sphalerite, of lead is galena, and that of copper and cadmium is sulfide, respectively. But, the mineralogical components of silver and indium in slag are opaque and probably stud in the crystal lattice of sphalerite with isomorphism. The speciation of zinc, cadmium, copper, and lead in the slag exists mainly in residual forms. The percentage of acidic extractable forms of metals in slag is low while that of reducible and oxidizable forms is high, respectively. In the South of China, the releasing potential of heavy metals from the slag is significantly affected by acid deposition, microbial effect and galvanic effect, and the recycling and toxicity reduction of nonferrous slag through bioleaching is evaluated.

Key words: nonferrous slag; heavy metal; mineral phase; three-stage BCR sequential extraction procedure; environmental availability

金属矿冶业是环境重污染行业。我国年产500万t的有色金属产品,所造成的以尾矿和废渣为主的工业固体废弃物每年就超过0.6亿t[1]。我国许多学者对从有色金属冶炼过程中产生的大量废渣中有价金属的综合回收进行了研究和探讨[2-5],但是,由于废渣中有价金属品位低,采用传统的湿法、火法或湿法-火法联用等技术回收其中有价金属时,存在回收成本高、经济效益差、环境污染严重等问题,从而导致废渣的综合利用率不高而大量自然堆置。在露天堆置过程中,冶炼废渣中金、银、镓、铟等有价金属和镉、铅、砷等有毒金属元素经自然风化和淋洗易释放到环境中,不仅对周边生态环境造成严重污染,而且造成大量的有价金属资源的浪费和流失[6]。目前,我国尾矿总库容达10亿m3,有色金属矿冶业待处理尾矿废渣量已达千亿吨。如何对这些固体废弃物进行“减量化、资源化、无害化”处理,是金属矿冶业面临的巨大难题。控制冶炼废渣中重金属的组分活性和环境污染行为,迫切需要发展环境友好、高效的冶炼废渣资源化和无害化技术。然而,国内关于有色冶炼废渣中重金属的环境活性和综合利用的研究甚少,尤其是对其环境危害与综合控治方面的研究极少,仅对土法炼锌废渣中Pb和Zn的存在状态及环境活性[7-8]有过报道。由于冶炼废渣中重金属全量并不能直接反映其潜在的环境效应,重金属的释放速度和环境活性取决于重金属的矿物组成、包裹程度、蚀变边结构和粒度大小等因素[9]。为此,本文作者通过扫描电子显微镜和X射线衍射仪对某铅锌冶炼废渣进行矿物相特征分析,结合BCR法连续提取废渣中重金属组分的赋存状态,阐明废渣中重金属在复杂环境体系中的环境化学活性、迁移能力等过程特征,为冶炼废渣的资源化和无害化提供科学依据。

1  材料与方法

1.1  冶炼废渣

该渣主要来源于我国南方地区某大型铅锌冶炼厂湿法炼锌中性-酸性复浸出工艺的浸出渣经挥发窑系统回收部分有价金属(锌、铅、铟、锗等)后所得到的二次渣,含有较多的铁和焦炭组分[10]。将采集的冶炼废渣自然风干,球磨,过0.1 mm筛后于105 ℃烘干,备用。

1.2  测试与方法

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