Method of operational control of antimony content in metallurgical samples of copper production

The optimal conditions for the preliminary chemical preparation of copper production metallurgical samples were found and the uncertainty of antimony determination by inductively coupled plasma atomic emission spectrometry in solutions obtained after sample digestion by sintering was assessed. Three copper production metallurgical samples with varying analyte concentrations — copper concentrate, metallurgical slag, and copper production dust — were used for the study. Sample preparation was performed by sintering with a mixture of sodium carbonate and zinc oxide, and the optimal digestion process parameters were established using a probabilistic-deterministic four-factor experimental design method at six levels. For copper concentrate and metallurgical slag samples, a significant influence of all four factors studied on the degree of antimony extraction from the solid phase into solution was established. For the copper production dust sample, the influence of only two factors — sample weight and the proportion of reagent in the mixture — was significant. It was found that the maximum degree of antimony extraction from the solid phase into solution is achieved with a sample weight of 0.1 g, a sintering temperature of 900°C, a reagent mass fraction in the sintering mixture of 75%, and a sintering time of 60 min. Based on the obtained results, a technique of antimony determination by ICP-AES in solutions obtained after sintering metallurgical samples was developed. The expanded uncertainty value was estimated for three test samples with different analyte concentrations: 0.044 ± 0.001 wt.%, 0.085 ± 0.012 wt.%, and 0.25 ± 0.08 wt.% The developed technique involves the determination of antimony content using ICP-AES in three analyte concentration ranges: 0.010 – 0.050, 0.050 – 0.10, and 0.10 – 0.30 wt.% The proposed method can be used in industrial laboratories for antimony content monitoring in various metallurgical samples of copper production.