<p>Copper smelting by-products are key raw materials for the production of selenium, tellurium, molybdenum, and rhenium. Understanding the distribution of these elements during the smelting process is critical for optimizing their directional enrichment, extraction, and utilization. This study investigates the distribution behavior of selenium, tellurium, molybdenum, and rhenium in the double-flash copper smelting process, using a copper smelter employing the double-flash process as a case study. Concentrations of selenium, tellurium, molybdenum, and rhenium were determined by inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma mass spectrometry. The distribution of selenium, tellurium, molybdenum, and rhenium in the copper smelting system was determined through establishing the system’s material balance and integrating elemental test results. The findings indicated that during double-flash copper smelting processing, 47.9% of selenium and 34.9% of tellurium entered the electrorefining process with the anode copper, while 52.1% of selenium and 65.1% of tellurium were retained in the slag, dust, and filtered flue gas. In the flash smelting stage alone, 80.8% of molybdenum was transferred to the slag, while 82.9% of rhenium was released with the flue gas, of which 7.0% was captured in the dust.</p> Graphical Abstract <p></p>