Already in 1527 Duke Heinrich II of Braunschweig-Lüneburg founded a lead and copper smelter on the site of today’s Harz-Metall GmbH, which from then on was known under the name Frau-Marien-(Saiger)-Hütte and later as Bleihütte Oker. In addition to the Frau-Marien-(Saiger)-Hütte on the Oker, the Frau-Sophien-Hütte on the Innerste near Langelsheim and the Herzog-Julius-Hütte on the Grane near Astfeld also belonged to the Unterharzer Metallhütten.
All ores that were processed in the three Unterharzer huts until the second half of the 20th century come from the Rammelsberg deposit near Goslar. Over a period of 1000 years, lead, silver, copper and zinc as well as numerous by-metals were extracted from them – until the mine was closed down in 1988.
After Frau-Marien-(Saiger-)Hütte had been state-owned by the states of Prussia and Braunschweig for several years, Preußische Bergwerks- und Hütten-Aktiengesellschaft – Preussag for short – and Unterharzer Berg- und Hüttenwerke GmbH were founded on 13 December 1923, four sevenths of which belonged to the private-sector company Preussag and three sevenths to Braunschweig GmbH. In 1967, all state shares in Unterharzer Berg- und Hüttenwerke GmbH were transferred to Preussag AG, which bundled its metal activities in Preussag AG Metall. One year later, further organisational measures followed, which combined Bleihütte Oker, Zinkoxydhütte Oker and Zinkhütte Harlingerode to form Hüttenwerk Harz.
With the depletion of the deposit and the decline in the metal price, the activities of Preussag AG Metall were adjusted. In 1986 Hüttenwerke Harz became part of the newly founded Harz-Metall GmbH, which continues to strengthen its position as one of the leading recycling companies for lead and zinc in Europe.