Zinc mine Schmalgraf

The zinc mine Schmalgraf, located in the valley of the Hohnbach near La Calamine, was called Comborn in the 15th century. Later it was also known as Drieschschacht or Klousterschacht. The last exploitation ran from 1868 to 1932. The mine had a depth of 190 meters, which is exceptionally deep for Belgian ore mines. Between 1862 and 1867, a mine tunnel was dug to the "Auwe Berg" to facilitate the transport of ore to the ore washing plant, which was located in Prussian Moresnet. This mine tunnel was named after the then-director, Oskar Bilharz, and was thus called Oskarstollen. From the Oskarstollen, a narrow gauge railway was built parallel to the Hohnbach to further transport the ore. About 30 miners worked in the open pit along the Hohnbach. In the underground mine, another 120 miners worked.

In the mine "Schmalgraf," especially sphalerite was mined because of lead (galena). The Schmalgraf mine was closed when the amount of lead was no longer profitable. Nowadays such a mine would not be closed because there is still enough zinc in it to exploit the mine profitably.

In front of the entrance to the Oskarstollen lies a meadow with zinc flora. Here grow among others zinc-cress (Thlaspi caerulescens ssp. calaminare), bladder campion (Silene vulgaris ssp. vulgaris var. humilis), sea thrift (Armeria maritima ssp. halleri), and zinc violet (Viola lutea ssp. calaminaria).

Parallel to the Hohnbach lies the old railway embankment that once connected the mine tunnels of the Oskarstollen with Kelmis. Today it serves as a walking path. Along the edges, zinc spoonleaf (Cochlearia pyrenaica) grows in marshy spots. The railway embankment consists of waste from the zinc factory and from slags from the smelters. These still testify to the transport of zinc-containing rock. The embankment is therefore particularly overgrown with zinc-cress (Thlaspi caerulescens ssp. calaminare) in the meadow.

Total production between 1867 and May 1, 1932:
22,641 tons of zinc ore, 333,654 tons of sphalerite, 21,188 tons of galena, and 29,295 tons of pyrite.

Michel