摘要
铊是一种典型的危险废物,在选冶过程中,再生锌原料中的铊以氧化物或粉尘的形式排放到环境中,严重污染环境并危害人类健康。再生锌成分复杂,若样品消解不完全,直接影响测定结果的准确性。通过比较微波消解和电热板常压消解对样品的处理效果表明,微波消解法快速环保,但是对于难消解的再生锌样品,因无高氯酸的加入,其氧化性能降低,无法将样品消解完全,导致铊测定结果偏低。而采用高氯酸-硝酸-盐酸-氢氟酸构成的混合酸并于低温加聚四氟乙烯盖电热板常压消解,能够有效地解决再生锌样品前处理难题。采用四酸法消解样品,5%盐酸进行浸取,选择Tl 190.794 nm为分析谱线,用电感耦合等离子体原子发射光谱(ICP-AES)法测定再生锌中铊。在仪器设定的最佳测定条件下,当Tl质量浓度为0.10~5.00μg/mL时,与发射强度线性关系良好,线性回归方程为y=180.77 x-0.46,相关系数为0.99998。干扰实验表明,在设定的共存离子干扰上限,Pb、Zn、Cu、Fe、Ca、Bi、Sb、Sn、As、Al、Cd、Si、Ag等对再生锌中铊的测定基本无影响。按照实验方法,对5个不同铊含量水平的再生锌样品进行11次独立测定,其测定范围为0.004%~0.21%,方法检出限为0.004μg/mL,相对准偏差(RSD)为2.1~3.2%,加标回收率为97.3%~108%。方法简单,操作性强,能够快速准确测定再生锌中铊。
Thallium is a typical hazardous waste.In the process of mineral selecting and smelting,the thallium in the recycled zinc raw material is discharged into the environment in the form of oxide or dust,which poses a serious threat to the environment and human health.The regenerated zinc composition is very complex.If the sample digestion is not complete,it directly affect the accuracy of the measurement results.In this paper,the effects of microwave digestion and electric hot plate digestion at atmospheric pressure were compared,and the results showed that the microwave digestion method was fast and environmentally friendly,but for the regenerated zinc samples that were difficult to digest,there was a significant decrease in the oxidative capacity without the addition of perchloric acid.So the sample was not completely dissolved,which directly resulting in the low thallium measurement results.However,the sample dissolved by a mixed acid composed of perchloric acid,nitric acid,hydrochloric acid-and hydrofluoric acid,covered with polytetrafluoroethylene cover at low temperature,and on electric heating plate under constant pressure,which effectively solved the pretreatment problem of regenerated zinc samples.In this experiment,the samples were digested by a mixed acid composed of nitric acid,hydrochloric acid,hydrofluoric acid and hydrochloric acid(volume ratio is 10∶5∶5∶3),extracted by 5%hydrochloric acid.Tl 190.794 nm was selected as the analysis line.The analytical method for measuring thallium in regenerated zinc by inductively coupled plasma atomic emission spectroscopy(ICP-AES)was established.Under the set optimal instrument conditions,when Tl mass concentration was 0.10μg/mL to 5.00μg/mL,the emitted light intensity showed a good linear relationship with the mass concentration,the linear regression equation was y=180.77 x-0.46,the correlation coefficient was 0.99998.The interference experiments showed that at the set upper limit of coexisting ion interference,Pb,Zn,Cu,Fe,Ca,Bi,Sb,Sn,As,Al,Cd,Si,Ag had almost no effect on the determination of thallium in regenerated zinc.According to the test method,thallium in five regenerated zinc samples with different content levels was measured 11 independent times,and the measurement range wasω(Tl)0.0041%—0.21%,the detection limit of the method was 0.004μg/mL,the experimental relative quasi deviation(RSD)was 2.1%—3.2%,and the recovery of spike was 97.3%—108%.The method is simple and operable,which can quickly and accurately determine thallium in regenerated zinc.
作者
孙计先
苏春风
罗海霞
SUN Jixian;SU Chunfeng;LUO Haixia(BGRIMM MTC Technology Co.,Ltd.,Beijing 102628,China)
出处
《中国无机分析化学》
CAS
北大核心
2023年第8期783-789,共7页
Chinese Journal of Inorganic Analytical Chemistry
基金
国家重点研发计划项目(2021YFC2903101)。
关键词
再生锌
电感耦合等离子体原子发射光谱
铊
危险废物
regenerative zinc
inductively coupled plasma optical emission spectrometry
thallium
hazardous wastes
