The current report describes the aspects related to the construction of two test cells as part of a
research program on the use of water cover as a means of reducing oxidation of acid generating
tailings. The aspects covered in this report include the construction of the test cells at Mine
Louvicourt.
The objectives of the field program were to:
- Create a test facility within the tailing impoundment which simulates as closely as possible
the conditions which might exist following the closure of Louvicourt basin. In order for this
facility to be representative of post closure conditions, it had to be isolated from mill
process water and replenished with natural water. - Instrument the test facility in a manner, which allows the collection of the necessary
hydrogeological and hydrological data for the study; - Regularly collect and analyse representative samples of cover water, tailings solids,
interstitial tailings porewater and groundwater to meet the overall study objectives
previously provided; and - Monitor the tailings basin in a manner which will allow the results of the laboratory and field
test programs to be related to actual conditions in the basin.
The field investigation included the design, construction and instrumentation of two test-cells, each
measuring about 20 m x 20 m, in an area adjacent to the Louvicourt tailings pond. Some
construction problems were encountered during construction and required deviation from the
proposed design. The presence of shallow bedrock and the proximity of the tailings pond resulted
in a slight relocation of the cells, a raising of the cell floor levels. Cells were also slightly different in
size and shape and ended up with sloped floors. Cells were filled with 2 to 3 m of tailings during
the first three weeks of August 1996 and covered using a 0.3 m deep water cover.
During filling of the cells, large variations of the geo-chemical characteristics of the tailings were
reported. This had a large impact on the reproducibility of in-situ testing between both cells. The
comparative characteristics of the surface of the tailings between the two cells are therefore different
and they are even different within each cell. Both test cells were provided with permanent
instrumentation consisting of a sampling well/piezometer installation and a battery operated pH
meter, water level and flow meter with continuous recorder at each cell overflow.
The goals of the program were met even though the difference in surficial tailings characteristics
between both cells restricts the capacity to directly compare results obtained from both cells.
