Elemental Assessment of Lead–Bismuth Sludge from Copper Smelting with Emphasis on Tellurium Recovery

<jats:p>Industrial by-products generated during copper smelting are increasingly regarded as promising secondary sources of strategically important and critical elements. Among such technogenic materials, lead–bismuth sludge formed during wet gas cleaning of sulfur-bearing gases represents a potentially valuable reservoir of selenium and tellurium. The present study provides a comprehensive elemental assessment of lead–bismuth sludge obtained from the Almalyk Mining and Metallurgical Complex (Uzbekistan). Prior to analysis, representative sludge samples were subjected to acid digestion using freshly prepared aqua regia, followed by elemental determination using inductively coupled plasma optical emission spectroscopy (ICP-OES). Particular attention was devoted to the distribution behavior of selenium and tellurium due to their technological importance as critical raw materials. The analytical results demonstrated that the investigated sludge is characterized by a pronounced polymetallic composition dominated by lead (20.0%), together with significant concentrations of iron (6.76%), copper (5.34%), and zinc (4.40%). Tellurium was detected at a concentration of 0.33%, indicating its selective accumulation in the lead–bismuth residue, whereas selenium was not detected under the selected analytical conditions. Based on elemental composition data and thermodynamic considerations, the investigated sludge may be considered a promising secondary source for tellurium recovery. The obtained results contribute to understanding the physicochemical behavior of chalcogen elements during copper smelting and wet gas-cleaning processes and may serve as a basis for the development of integrated recycling approaches for technogenic metallurgical waste.</jats:p>