The copper production plant was built near the town of Pirdop in the period 1955-1958 with four main production units: Smelter, Refinery, Acid Plant and Precious and Rare Metal Production. On November 21, 1958 the first anode copper was produced, and on December 6 of the same year the plant was officially opened.
In September 1997, the international company Union Miniere headquartered in Brussels, Belgium signed a privatization contract with the Bulgarian government, thus acquiring the plant in Pirdop. In April 2005, the Umicore Group’s copper production was differentiated into a separate company – Cumerio, listed on the stock exchange in Brussels.
In April 2008 the Cumerio Group was acquired by Norddeutsche Affinerie AG (NA) after approval by the European Commission at the beginning of the year. The new company became the largest copper producer in Europe and the global leader in copper recycling.