Former ore preparation and flotation works of the Meggener Bergbau at Lennestadt-Meggen, part of the Sachtleben Grube Sicilia complex that operated from 1852 to 1992, with the ore processing infrastructure once making Meggen the largest zinc-concentrate p
Site 532 corresponds to the valley floor location in Lennestadt-Meggen associated with the ore preparation and processing works of the Meggener Bergbau — the downstream component of the Sachtleben Grube Sicilia complex, distinct from the Siciliaschacht shaft and museum site on the hillside above (site 534). The Meggener ore deposit, a sedimentary massive sulphide body deposited approximately 370 million years ago, yielded Schwefelkies (pyrite, FeS₂), Zinkblende (sphalerite, ZnS), Bleiglanz (galena, PbS), and Schwerspat (barite, BaSO₄). Ore extraction at Meggen and the adjacent Halberbracht commenced in 1852, initially mining the 'eiserner Hut' (gossan) of the pyrite deposit.
With the construction of the Lennetalbahn in the 1860s, output grew dramatically and at the end of the 1920s Meggen was the world's leading barite and pyrite producer, holding a 22 per cent share of world barite output and 25 per cent of German pyrite production. A structural transformation in 1962–1963 introduced a new Flotationsanlage (flotation plant) which for the first time allowed the fine-intergrown zinc and lead sulphides to be separated into marketable concentrates. From 1961 to 1977 the mine was the largest zinc-concentrate producer in western Europe.
Pyrite concentrate was dispatched daily by special train to the Schwefelsäureanlage of Sachtleben Chemie in Duisburg-Homberg; barite reserves were exhausted in 1977. As the zinc grade in the ore fell from an initial 10 per cent to below 6 per cent by 1982, the mine became uneconomic. The final shift was worked on 31 March 1992.
The Meggener ore body was identified as a significant commercial resource in the early nineteenth century. By 1852 systematic mining of the pyrite outcrop ('Eiserner Hut') had begun at both Meggen and the adjacent Halberbracht field by a number of small Gewerkschaften. The key infrastructure development enabling growth was the opening of the Lennetalbahn in the 1860s, which connected Meggen to the main railway network for the first time and allowed bulk ore shipments.
Demand for Schwefelkies as the primary feedstock for sulphuric acid production drove expansion through the Gründerjahre. By 1871 the district included 175 Gruben and 6 Erbstollen. The large economic depression from the mid-1870s caused a downturn, partly offset by the introduction of barite (Schwerspat) production from 1890. At the end of the 1870s, the chemist Dr Rudolf Sachtleben developed a process for producing the white pigment Lithopone from barium sulphate and zinc sulphide; this required both commodities present in the Meggener deposit, and he subsequently concluded supply agreements with the Gewerkschaften before merging with the Gewerkschaft Siegena in 1906 to form the Gewerkschaft Sachtleben headquartered in Homberg am Rhein.
During the First World War, the mines' kriegswichtige Bedeutung (strategic wartime importance) caused an exceptional boom: between 1915 and 1918 the workforce grew from approximately 1,500 to nearly 3,000 workers and output reached 700,000 tonnes. During the Weimar Republic, the Frankfurter Metallgesellschaft AG acquired part of the shares in both Gewerkschaften, enabling the purchase of smaller neighbouring mines to concentrate all production in a single enterprise. By the end of the 1920s, Meggen was the world's leading Schwerspat and Schwefelkies producer: the global barite market share was 22 per cent and the share of German pyrite production was 25 per cent.
During the Second World War, output was pushed to three times normal levels using Kriegsgefangene (prisoners of war) and Zwangsarbeiter (forced labourers), reaching over one million tonnes annually with a total belegschaft of 4,191 by 1943–44. A new Seilfahrtsschacht (the later Siciliaschacht) was sunk shortly after the Währungsreform of 1948, entering service in the early 1950s and providing the modern hoisting and access infrastructure described at site 534.
From the end of the 1950s the market for Schwefelkies contracted sharply as sulphur became available as a waste product of natural-gas refining. This prompted the structural transformation of 1962–63: a new Flotationsanlage was commissioned which for the first time separated the finely intergrown zinc and lead sulphides from the pyrite matrix, yielding Zinkkonzentrat, Bleikonzentrat, and angereicherten Pyrit as separate saleable products. Zinc concentrate, which commanded the highest price, became the primary revenue stream. The pyrite-enriched fraction was transported daily by Sonderzug (special train) to the Schwefelsäureanlage of Sachtleben Chemie in Duisburg-Homberg. From 1961 to 1977 the mine was the largest zinc-concentrate producer in western Europe. Large underground diesel and battery vehicles replaced earlier tracked equipment, and to provide access for these machines a Walther-Rampe — an inclined roadway with a gradient of 1:8 — was driven to connect the surface to the 650-metre level.
Barite (Schwerspat) reserves were exhausted in 1977, ending barite production after nearly a century. The zinc grade in the run-of-mine ore, which had initially been 10 per cent Zn, declined steadily with increasing depth and by 1982 had fallen below 6 per cent, the economic threshold for profitable operation. The final shift at the Meggener Bergbau was worked on 31 March 1992; approximately 250 employees were affected. Reclamation and landscaping of the surface followed closure.