Physicochemical and environmental characteristics of alkali leaching residue of wolframite and process for valuable metals recovery  

黑钨精矿碱浸渣理化与环境特性及有价金属回收工艺

作　　者：Yuan-lin CHEN Xue-yi GUO Qin-meng WANG Qing-hua TIAN Jin-xiang ZHANG Shao-bo HUANG 陈远林;郭学益;王亲猛;田庆华;张金祥;黄少波(中南大学冶金与环境学院,长沙410083;赣州有色金属研究所,赣州341000;长沙矿冶研究院有限责任公司,长沙410012摘要:采用XRD、SEM−EDS、化学物相分析、MLA和TG−DSC等方法研究)

机构地区：[1]School of Metallurgy and Environment,Central South University,Changsha 410083,China [2]Ganzhou Nonferrous Metallurgy Research Institute,Ganzhou 341000,China [3]Changsha Research Institute of Mining and Metallurgy Co.,LTD,Changsha 410012,China

出　　处：《Transactions of Nonferrous Metals Society of China》2022年第5期1638-1649,共12页中国有色金属学报（英文版）

基　　金：the financial supports from the National Key R&D Program of China(No.2019YFC1907400);the National Natural Science Foundation of China(Nos.51904351,51620105013)。

摘　　要：Physicochemical and mineralogical characteristics of an alkali leaching residue of wolframite were studied by XRD,SEM−EDS,chemical phase analysis,mineral liberation analyzer(MLA),and TG−DSC methods.Batch leaching tests,toxicity characteristic leaching procedure(TCLP)tests and Chinese standard leaching tests(CSLT)were conducted to determine the environmental mobility of toxic elements.The results show that,due to the high contents of W,Fe,Mn,Sn,and Nb,the residue is with high resource value,but the content of a toxic element,As,is also high.The existing minerals of the investigated elements mainly occur as monomer particles,but it is difficult to extract these valuable metals by conventional acid leaching due to their mineral properties.The release of As increases over time in acidic environment.The leaching concentration of all investigated harmful elements through TCLP is within the limiting value,while the leaching concentration of As through CSLT exceeds the limiting value by more than 4 times,so the residue is classified as hazardous solid waste based on the Chinese standard.A process for valuable metals recovery from this residue was proposed.Preliminary experimental results indicated that the main valuable metals could be extracted effectively.采用XRD、SEM−EDS、化学物相分析、MLA和TG−DSC等方法研究黑钨精矿碱性浸出渣的理化特性和矿物学特性,并采用批次浸出实验、毒性浸出程序(TCLP)实验、国家标准毒性浸出测试(CSLT)分析浸出渣毒性元素的环境释放特性。结果表明,浸出渣中W、Fe、Mn、Sn、Nb等有价金属含量高,具有很高的资源价值,同时也含有高含量毒性元素As。有价金属矿物主要以单体形式存在,但由于矿物性质,难以通过常规酸浸工艺提取有价金属。浸出渣中As向环境的释放量随时间增长而增加。TCLP结果表明,所有毒性元素浸出浓度均未超标;而CSLT结果表明,As浸出浓度超过国家标准限值4倍以上。因此,该浸出渣被列为危险固体废物。提出一种从浸出渣中回收有价金属的工艺。实验结果表明,采用该工艺可有效回收浸出渣中的有价金属。

关 键 词：alkali leaching residue physicochemical characteristics environmental characteristics valuable metals recovery 

分 类 号：X758[环境科学与工程—环境工程] TF803[冶金工程—有色金属冶金]