Gerhard Knitzschke/Martin Spilker:
The Mansfeld/Sangerhausen copper slate deposits
Mining use and preservation
Originally it was planned to continue to mine copper slate in the Mansfeld and Sangerhausen mining area until 2012 although after 1970 production was already restricted exclusively to the Sangerhausen region. However, at the beginning of 1989 it was decided to stop production in 1995 as a result of the steadily declining quality of the deposits, the increasingly complicated hydrological conditions and the consequent falling production rates and rising mining costs.
The closure of the Bessemer processing plant of the copper and silver smelting works in Hettstedt in November 1989 for environmental reasons interrupted the continuous processing of the copper slate ore to electrolyte copper and the production of fine silver from the low-grade matte smelted out of the ore in the furnaces of the smelting works. This made it necessary to change the mining concept and finally led to the decision to already stop mining production on 30 September 1990. Thus production ceased in one of the oldest continually operated mining areas in the world after nearly 800 years. Together with the ore smelting and metal-working industries, it had provided the people in this region with a secure livelihood for many centuries.
The Mansfeld mines and smelting works have left an indelible imprint on the roughly 400 km² region around Eisleben, Hettstedt und Sangerhausen having a positive influence on the economy and a negative impact on the environment.