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<RGC: Project Experience
IAA Culmitzsch Tailings Impoundment
Ronneburg Mining District, Germany
- Client: Wismut GmbH
- Years of Service: 1995 to present
- Project Description:
- The Wismut mining company was responsible for the development and
operation of the East-German uranium mines under Russian control from the
1940s to reunification in 1989. During this period these mines employed up to
100,000 people and were responsible for the production of about one third of the
Soviet blocks uranium production. One of the principal mining areas was in
Thuringia where a huge complex of open pits, notably the 300m deep pit at
Ronneburg and underground mines, over 300 million m3 of
waste pits, two treatment plants and 6 tailings dams containing more than 100
million tons of tailings cover an area of approximately 32 km2.
Immediately following unification of Germany, the mining
operations were discontinued and a fund of approximately 14 billion
DM (10 billion US dollars) provided for the clean-up
and remediation of the uranium mining areas at an expenditure value of about 1
billion DM per year. This makes it the single biggest mining rehabilitation
project in the world.
- Robertson GeoConsultants was appointed by Wismut to develop
the methods and technology for the placement of cover layers on the very soft
(weak) tailings in the pond zone of the Helmsdorf tailings impoundment. These
extremely weak (essentially fluid) tailings require special techniques to increase
their consolidation sufficiently to enable conventional cover placement
techniques to be used. This study involved the use of finite strain consolidation
theory to develop a model which predicts
the rates of consolidation and pore pressure dissipation within the slimes zone under self weight as well as the incumbent loads of cover layers and placing
equipment. The effects of short and long band drains were modelled for both
short and long term effects. Available computer codes were not able to perform
the modelling, and additional model development had to be done for the project.
The study resulted in the development of alternative cover placement
methodologies and the demonstration of the analytical methods for their
design.
- Services Provided:
- Design of remedial strategies for large uranium tailings impoundment
- Modeling consolidation of fine tailings under self-weight and proposed cover placement
- Assessment of long-term seepage from tailings impoundment
Papers:
Wels, C., Robertson, A. MacG., and Jakubick, A.T.(2000):
"A Review of Dry Cover Placement on Extremely Weak, Compressible Tailings".
Paper published in CIM Bulletin, Vol. 93, No. 1043, pp. 111-118, September 2000.
Wels, C., Robertson, A.MacG., and Jakubick, A.T.(1999):
"A Review Of Dry Cover Placement On Extremely Weak, Compressible Tailings".
Paper presented at Sudbury '99 - Mining and the Environment II; Conference held
September 13-15, 1999, Sudbury, Ontario.
Wels, C., Robertson, A.MacG., and Jakubick, A.T.(1999):
"Cover Placement on Extremely Weak, Compressible Tailings".
Paper presented at the Soft Tailings Stabilization Workshop, May 26-27, 1999, Edmonton,
Alberta.
Wels, C., Barnekow, M., Haase, M., Exner, M., and Jakubick, A.T.(2000):
"A Case Stucy On Selfweight Consolidation Of Uranium Tailings".
Paper presented at Uranium 2000; Conference held September 9-15, 2000, Saskatoon, Saskatchewan.
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