Determination of Lead in Argentalium Ores Containing Barite by Inductively Coupled Plasma-Atomic Emission Spectrometry

Acid digestion (aqua regia, tetracid), as a conventional method, is usually used for dissolving Ag-Pb deposit to detect Pb. However, samples containing 40%-80% of barite are difficult to dissolve completely, possibly causing low results for Pb. Additionally, determination results can also be affected due to the formation of double salt precipitation from BaSO₄ reacting with Pb. In this paper, a novel method for dissolving Ag-Pb ores by Na₂O₂ and determination of Pb by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) combining with high salt nebulizer was proposed. Experimental conditions such as sample volume and multiple dilutions were optimized. The detection limit was 0.013%, RSD was 1.1%-1.6% and recovery was 97.9%-102.9%. The samples were decomposed completely by alkali fusion with Na₂O₂. The addition of BaCl₂ can eliminate the influence of sulfate on Pb for barite-bearing sample. However, there is no effect for non-barium-barite samples. This method solves the problems of both difficult and complete decomposing for Ag-Pb ores with high content barite and the influence of BaSO₄ in the quantification of Pb.