偏硼酸锂熔融-电感耦合等离子体原子发射光谱法测定锆矿石中10种元素

锆矿石作为一种重要的战略性矿产,准确分析锆及其共伴生有用有害元素含量对综合评价锆矿资源具有重要意义。然而锆矿石是一种难溶矿石,且在制样过程中Zr、Hf容易水解沉淀。实验通过样品前处理方法的选择和仪器工作条件的优化,建立了偏硼酸锂熔融,稀硫酸+酒石酸提取后电感耦合等离子体原子发射光谱法(ICP-AES)测定锆矿石中Zr、Hf、K、Na、Ca、Mg、Al、Fe、Ti、Mn等10种元素(以氧化物计)含量的方法。利用偏硼酸锂的熔融分解特性制样,熔剂质量为样品质量5倍时可取得较好的处理效果;稀硫酸提取液中加入酒石酸可以抑制Zr、Hf水解;设定仪器工作条件为发生器功率1.3kW、进样速度1.0mL/min、雾化气流量0.7L/min;选择Zr 343.823nm、Hf 277.336nm、K 766.490nm、Na 589.592nm、Ca 317.933nm、Mg 285.213nm、Al 396.153nm、Fe 238.204nm、Ti 334.940nm、Mn 257.610nm为分析谱线进行测定,采用基体匹配法绘制校准曲线消除基体效应的影响。方法中各元素校准曲线的线性相关系数均大于0.9990;各元素的检出限为1.57~58.8μg/g。方法用于测定锆矿石成分分析标准物质GBW07156、GBW07157中Zr、Hf、K、Na、Ca、Mg、Al、Fe、Ti、Mn(以氧化物计),结果的相对标准偏差(RSD,n=10)为0.67%~4.1%,相对误差(RE)为0.13%~4.8%。按照实验方法测定实际样品中各元素(以氧化物计),结果的相对标准偏差(RSD,n=5)为0.27%~4.4%。方法能快速、完全地分解锆矿石,并有效避免Zr、Hf元素的水解,适用于锆矿石中10种元素的准确分析。

Determination of ten elements in zirconium ores by lithium metaborate fusion-inductively coupled plasma atomic emission spectrometry

Zirconium ore was an important strategic ore resource. The accurate analysis of zirconium as well as its intergrowth useful and harmful elements had great significance on the comprehensive evaluation and utilization of zirconium ore resources. However, zirconium ore was insoluble, and hydrolytic precipitation of Zr and Hf easily occured in sample preparation process. Based on the selection of sample pretreatment method and the optimization of instrumental working conditions, the analysis method of ten elements (in oxides, including Zr, Hf, K, Na, Ca, Mg, Al, Fe, Ti and Mn) in zirconium ore by inductively coupled plasma atomic emission spectrometry (ICP-AES) was established after lithium metaborate fusion and dilute sulfuric acid-tartaric acid extraction. The sample was prepared according to the fusion decomposition characteristic by lithium metaborate. The sample treatment effect was good when the mass of flux was five times of sample mass. The hydrolysis of Zr and Hf could be inhibited by adding tartaric acid into dilute sulfuric acid extracting solution. The working conditions for the instruments were set as follows: the power of generator was 1.3kW; the sample injection speed was 1.0mL/min; the flow rate of atomized gas was 0.7L/min; Zr 343.823nm, Hf 277.336nm, K 766.490nm, Na 589.592nm, Ca 317.933nm, Mg 285.213nm, Al 396.153nm, Fe 238.204nm, Ti 334.940nm and Mn 257.610nm were selected as the analytical lines; the influence of matrix effect was eliminated by preparing the calibration curve using matrix matching method. The linear correlation coefficients of the calibration curves for testing elements were all higher than 0.9990. The limit of detection was 1.57-58.8μg/g. The proposed method was applied to the determination of Zr, Hf, K, Na, Ca, Mg, Al, Fe, Ti and Mn (in oxides) in certified reference materials of zirconium ore (GBW07156 and GBW07157). The relative standard deviations (RSD, n=10) of determination results were between 0.67% and 4.1%. The relative errors (RE) were 0.13%-4.8%. The contents of elements (in oxides) in actual sample were determined according to the experimental method. The relative standard deviations (RSD, n=5) of determination results were between 0.27% and 4.4%. The zirconium ore could be rapidly and completely decomposed. The hydrolysis of Zr and Hf could be effectively avoided. The proposed method was applicable for the accurate analysis of ten elements in zirconium ore.