基体分离-电感耦合等离子体发射光谱法测定赤泥中的稀土氧化物  

Matrix Separation-Determination of Rare Earth Oxides in Bauxite by Inductively Coupled Plasma-Atomic Emission Spectrometry

作　　者：胡璇 程紫辉 张树朝[2] 石磊[2] HU Xuan;CHENG Zi-hui;ZHANG Shu-chao;SHI Lei(Guobiao(Beijing)Testing&Certification Co.,Ltd.,Beijing 100088,China;China National Quality Supervision and Inspection Center for Light Metal,Zhengzhou 450041,China)

机构地区：[1]国标(北京)检验认证有限公司,北京100088 [2]国家轻金属质量监督检验中心,河南郑州450041

出　　处：《光谱学与光谱分析》2022年第10期3130-3134,共5页Spectroscopy and Spectral Analysis

基　　金：中国铝业股份有限公司技术标准项目(ZY2019GZC01)资助。

摘　　要：从赤泥中提取稀土金属,开发高附加值产品,对保护环境特别是提高矿产资源的综合利用率以及实现可持续发展有着重要的意义。赤泥中的稀土元素含量较低(0.0010%~0.050%),且存在大量的铝和铁等基体元素,如何掩蔽基体元素对稀土元素的干扰是准确定量的关键。传统酸溶法会造成部分元素消解不完全,难以准确定量,回收率低,碱熔法则会由于引入大量的碱熔剂造成严重的基体干扰,同时还会堵塞雾化器。采用氢氧化钠熔融赤泥,熔融物用热水浸取,三乙醇胺溶液掩蔽铝和铁,乙二胺四乙酸二钠溶液络合钙、镁等干扰元素,稀土氢氧化物留存于沉淀中,沉淀经盐酸溶解进入待测液,从而将稀土元素与熔剂和基体元素分离。实验结果表明:标准溶液无需基体匹配,各稀土氧化物校准曲线的线性相关系数均不小于0.9999,检出限在0.0002%~0.0015%之间;按照实验方法分析实际样品中稀土氧化物的含量,测定结果的相对标准偏差(RSD,n=6)为2.5%~7.2%,回收率为85.0%~105.0%;本方法与电感耦合等离子体质谱法(ICP-MS)相比,两种方法的测定结果无显著性差异。ICP-OES实现了赤泥中稀土氧化物的同时测定,为今后分析赤泥中的稀土氧化物奠定了基础。Extracting rare earth elements from hematite and developing high-value-added products can improve the comprehensive utilization of mineral resources,inject resources into enterprises and promote the development of high and new technology.The content of rare earth oxides in red mud is low(0.0010%~0.050%),and there are many matrix elements such as aluminum and iron in red mud.How to eliminate the interference of matrix elements in the determination of rare earth oxides is important.The traditional acid dissolving methods can cause incomplete digestion of some elements,which are difficult to quantify accurately and has a low recovery rate.In contrast,the alkali fusion methods can introduce a large amount of alkali flux and cause serious matrix interferences,also block the atomizer at the same time.Red mud was melted with sodium hydroxide and extracted with hot water.Triethanolamine solution was used to eliminate the matrix interferences of aluminum and iron,EDTA disodium solution was used to complex with calcium,magnesium and other interfering elements,and rare earth hydroxide was retained in the precipitation,precipitation was dissolved into the liquid to be tested by hydrochloric acid.Thus rare earth elements were separated from fluxes and matrix elements.The experiment showed that the standard solution did not need matrix matching,the linear correlation coefficients of the calibration curve were not smaller than 0.9999,and the detection limits were 0.0002%~0.0015%.The relative standard deviations of rare earth oxides in the sample were between 2.5%and 7.2%,recovery rates were between 85.0%and 105.0%;results of inductively coupled plasma mass spectrometry(ICP-MS)were consistent with that of ICP-OES.ICP-OES realized the analysis of rare earth oxides in red mud in the future.

关 键 词：赤泥 稀土氧化物 氢氧化钠 基体分离 电感耦合等离子体发射光谱法 

分 类 号：O657.31[理学—分析化学]