Metallography of tailings from the Mansfeld copper mining area

Abstract The copper slate deposit of the Mansfeld copper mining area was mined in the 19 th and 20 th century. Mineral collectors can still find traces of copper smelting activities on the slag heaps of the various copper smelters. A piece from the Krug smelter slag heap mainly consists of Cu and Fe sulfides. The piece in question might be the intermediate product copper matte. The pieces from Hettstedt and the August Bebel smelter contain clearly visible metallic copper. The Hettstedt specimen might be a piece of furnace lining with adhering slag. Cr and Mg could be found, suggesting that chromium magnesia was used as refractory material. The piece from the August Bebel smelter contains up to 18 wt. % Cu. It does, however, not contain any sulfur. It is most likely Fe 2 SiO 4 slag (fayalite) with a high proportion of FeO. The presence of Sn and Zn suggests that this slag was formed during the processing of bronze or brass.