Improvements to the Aurubis Bulgaria Copper Plant 2014–2024

The Pirdop Copper Plant started construction in 1955 and was commissioned in December 1958 in Pirdop, Srednogorie region, Bulgaria. From then on, the plant has continuously and significantly improved its smelter processes, working conditions, and operational practices. Outokumpu Flash Smelting technology was adopted in 1987 with a nominal design capacity of 50–60 tons of blend per hour. Since then, the flash smelting furnace (FSF) capacity has increased four-fold, improving the plant’s performance. Many modifications and improvements were implemented on the FSF supporting facilities to remediate worn equipment and allow increased FSF throughput. Currently, the primary copper smelting process in Aurubis Bulgaria includes a FSF with a single jet burner with design capacity of 240 t/h. The FSF is supported by concentrate blending and drying units, PSC converters, twin casting wheels, two separate Sulfuric Acid production lines, Electrorefinery (Tank house), and a Slag Flotation Plant, the latter—unique for the Aurubis Group. This paper outlines the technological improvements carried out in the smelter and the sulfuric acid production. These include higher safety standards, technological upgrades, equipment replacement, modernization and modification, and increased environmental protection, for a ten-year period (2014–2024). All these improvements significantly contributed to higher concentrate throughput, equipment life and plant availability.