Fergus Murphy - Civil Engineer - Robertson GeoConsultants

Clap! The sound a big volume of mining proceedings made when it landed on my desk this morning. Dropped from on high, this volume is the collection of technical papers from an International Symposium on closure of uranium mines at Wismut in Germany. If you haven’t heard of Wismut, then I suggest you get a quick bit of background information from a previous posting on ithinkmining. I have trawled the internet in search of an electronic copy of the preceedings but I can’t seem to come up with any. If anyone has a link, let me know and I’ll repost it.

What I can do is give you a link to one of the papers included in the preceedings, which relates to the advances from the Wismut project with regard to soft tailings technology. The new East-West German Government inherited the Wismut problem in the formation of the new state, and by 1994 it became clear that existing cover technology was insufficient to overcome the pulpy soft tailings on large fine tailings areas. A new solution had to be devised. The principal strategy involved was to:

apply incremental light loads to cause consolidation and transform of a ‘liquid’ into a soil in order to handle it as a soil from a geotechnical point of view”

In order to enhance consolidation, wick drains were installed into the fine tailings to help dissipate excess pore pressures induced by the cover loads. This project has major relevance to mining in Canada as it is the technology and techniques developed at Wismut, that were used at Suncor’s Pond 5 for cover design and construction. Very similar challenges were faced in the oil sands and this paper describes how the techniques were adapted to accommodate the mature fine tailings (MFT) produced in that part of the world.

Cover design is an extensive topic and this is an example of but one niche. For a more general overview of cover technology I direct you the new Technology Review on Covers. It gives an overview of how covers are used in mining and provides links to online resources that can be used to obtain more information on the topic. Best of all, it is also free.