China Nonferrous Metallurgy

Thallium and its compounds are highly toxic. There are environmental pollution risks in the production process of zinc hydrometallurgy process.However, the existence of thallium in the intermediate materials of zinc hydrometallurgy process is complex, and the content is low and unstable, which makes it difficult to track, monitor and detect thallium in the intermediate materials of zinc hydrometallurgy process. In this paper, iron salt and potassium bromide extraction were used to eliminate the interference of thallium determination by complex matrix components. The [TlBr₄]_- complex anions formed by Tl³⁺ and Br^- were quantitatively extracted by methyl isobutylmethone (MIBK). Finally, thallium in the organic phase was determined. By optimizing the instrument measurement conditions, the graphite furnace ash temperature was 400℃, the atomic temperature was 1650℃, thus realizing the accurate determination of thallium content in the intermediate materials of zinc smelting process. The detection limit of the method was 0.27μg/L, RSD＜10%, and the added standard recovery rate was 95.2%~102.6%. The method was verified by the national standard material, and the results were accurate and reliable.