The Lichtenberg open pit mine

The Lichtenberg open pit uranium mine
Lichtenberg open pit mine 1991

One of the most notorious legacies of SDAG Wismut is the Lichtenberg open pit mine. Mining turned the site of the erstwhile towns of Schmirchau, Lichtenberg, and Gessen into a hole almost one kilometre wide and two kilometres long. Its maximum depth was 240 metres. A waste rock pile landscape emerged around the open pit. It all began in 1958: when spontaneous fires halted underground uranium mining at the Lichtenberg site, production switched to surface mining. On balance, rock production from the Lichtenberg open pit amounted to some 160 million cubic metres from which 13,000 tonnes of metallic uranium were produced.

A full-blown armada of technical means was committed to the development work. Winning of the uranium-bearing rock was by blasting work: blast holes were drilled in the rock, and the subsequent blast fragmented the rock material. The ore-bearing rock was then hauled away. At times, more than 150 vehicles were committed to the haul job. The trucks used were of Soviet manufacture: SIS of 3 tonnes capacity at the beginning, KRAS of 12 tonnes capacity later. Such payload pales in comparison with the off-highway trucks used by Wismut GmbH today in the framework of open pit backfilling and which carry up to 136 tonnes. Dumping of the waste rock was by conveyor belts and stackers.

In 1976, ore production from the Lichtenberg open pit came to a halt when the advancing pit hit the boundary of the town of Ronneburg to the north and that of the Schmirchau underground mine to the east. The various mines at the site then used the worked-out open pit as an internal dump until 1990. When remediation started as directed by Federal law, the remedial concept for the Ronneburg site proposed the complete backfilling of the former open pit.

In detail, it proposes the relocation of all waste rock piles located south of the A4 motorway (with the exception of pile #381) into the worked-out Lichtenberg open pit. Early in 2008, the Schutzdamm Ronneburg mine dump was the last to be relocated at the Ronneburg site, thus bringing mine dump relocation to an end.

Remediation of the former Lichtenberg open pit mine by Wismut GmbH will safely enclose more than 125 million cubic metres of waste rock in the emerging landscape structure.

The focus today is on capping the constructed fill body as well as on the construction of trails and hydraulic engineering work. A surface in excess of 215 ha had been capped with a two layer cover by 2015. After completion, the trail network shall have a total length of 20 km and ditches to catch and control surface water run-off of more than 21 km.

The twin-mount fill body will continue to call to mind the region's former mining activities. On the occasion of the national horticultural exhibition held in 2007, the "New Ronneburg Landscape" was presented to the public. The specific architecture is to make future visitors to the region aware of the efforts and achievements of Germany's largest environmental restoration project as well as of bygone mining operations.

Refilled Lichtenberg open pit 2015

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