Determination of Scattered Elements in Lead-Bismuth Smelting Slag by Inductively Coupled Plasma-Mass Spectrometry with Sodium Peroxide Melting

Scattered elements have become indispensable strategic resources, and recycling from lead-bismuth smelting slag can alleviate the problem of resource shortage. Lead content in the lead-bismuth smelting slag ranges between 28.12% and 29.45%, primarily existing as insoluble lead sulfate. X-ray fluorescence spectroscopy (XRF) and X-ray diffraction (XRD) were employed to analyze the matrix characteristics of lead-bismuth smelting slag, providing guidance for sample pretreatment methods and optimization of ICP-MS analytical conditions. A method for the accurate determination of ⁷¹Ga, ⁷³Ge, ⁷⁸Se, ¹¹¹Cd, ¹¹⁵In, ²⁰⁵Tl and ¹²⁵Te by ICP-MS was established through sodium peroxide melting and dilute sulfuric acid extraction. The experimental conditions such as flux dosage, melting time and leaching solution were optimized. Experimental results show that correlation coefficient (r) value of the scattered elements is 0.9991-0.9999, method detection limit is 0.0007-0.0221μg/g, and quantitative limit is 0.0023-0.0737μg/g. The method was applied to GBW07235 and GBW07236, and the absolute value of the standard error (RE) ranges from 0 to 8.85%, and the relative standard deviation (RSD, n=7) was between 2.1% and 4.2%. This method is also applicable to the determination of scattered elements in actual samples of lead and bismuth slag and relative results are in accordance with the recoveries of 90%-110% specified by DZ/T 0130—2006.