改进化学顺序提取-电感耦合等离子体质谱法应用于铅锌尾矿中铜铅锌镉镍的化学形态分析

采用改进化学顺序提取(BCR)法提取铅锌尾矿样品中铜、铅、锌、镉和镍等重金属元素的可交换态(F1)、可还原态(F2)、可氧化态(F3)和残渣态(F4)四种形态,利用电感耦合等离子体质谱法(ICP-MS)测定了铅锌尾矿中铜、铅、锌、镉和镍的各元素总量及各元素不同形态含量。研究结果表明:各元素不同形态的方法检出限在0.012~0.85 mg/kg之间,测定结果的相对标准偏差(RSD,n=5)在2.1%～9.9%之间;各元素所有形态量的总和与各元素测得总量的比值在88.1%～101.2%之间。这说明实验所用的形态分析方法适用于铅锌尾矿中铜、铅、锌、镉和镍的形态分析。采用实验方法对3个铅锌尾矿样品进行分析测定,结果表明铜、铅、锌、镉和镍的化学形态中残渣态含量最大,占各元素总量的30%及以上;铅和锌含量分布从高到低的顺序依次为F4、F2、F1、F3,铜和镍为F4、F3、F2、F1,镉为F4、F1、F3、F2。实验方法可为铅锌尾矿区中重金属元素的综合利用、环境影响评价及环境治理提供重要参考信息。

Application of modified chemical sequential extraction-inductively coupled plasma mass spectrometry to determination of chemical speciation of copper,lead,zinc,cadinum and nickel in lead and zinc tailings

Four chemical forms (i.e., exchangeable form(F1), reducible form(F2), oxidable form(F3) and residual form(F4)) of heavy metal elements including copper, lead, zinc, cadmium and nickel in lead-zinc tailings were extracted by modified chemical sequential extraction (BCR) method. Then, the total amount and the content of each speciation of copper, lead, zinc, cadmium and nickel in lead-zinc tailings were determined by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the detection limits of method for each speciation of these four elements were between 0.012 mg/kg and 0.85 mg/kg, and the corresponding relative standard deviations (RSD, n=5) were between 2.1% and 9.9%. The ratios of the content sum of all speciations to the total measured value for each element were between 88.1%-101.2%. It indicated that the proposed method was applicable for the speciation analysis of copper, lead, zinc, cadmium and nickel in lead-zinc tailings. Three lead-zinc tailings samples were determined according to the experimental method. The results showed that the content of residual form of copper, lead, zinc, cadmium and nickel accounted for the maximum proportion with not less than 30% of total content. The content distribution sequence from high to low for lead and zinc was F4, F2, F1, F3. For copper and zinc, the sequence was F4,F3,F2,F1, while it was F4,F1,F3,F2 for cadmium. This proposed method provided important reference information for the comprehensive utilization of heavy metal elements in lead-zinc tailings region, the environmental impact assessment and the environmental governance.