Solution collection provisionally stabilised

The BGE is currently managing to collect larger quantities of salt water in the vicinity of the former main collection point at the 658-metre level. At present, this amounts to some 10.5 cubic metres per day, which almost corresponds to the long-term average for previous years. In parallel with this development, less solution is being collected in the “yielding arch support section” at the 725-metre level, where the recent daily collection rate has only been around 2.6 cubic metres per day.

For comparison, in April this year, more than 10 cubic metres were still being collected there every day. The coming weeks will show whether the collection rate in the yielding arch support section will decline further – namely to the original level before the changes occurred in the influx of solution.

“At present, we’re confident that the increased collection rates in the area around the former main collection point will remain stable over a longer period of time and that we are pumping the salt water out at the right place. The decline in the collection rate in the yielding arch support section shows we’re on the right track,” says Iris Graffunder, Chair of the Management Board.

In parallel with the ongoing work below the former main collection point, miners are now also working their way southwards above the liner until they reach the end of the excavation. Based on the insights obtained, they plan to examine whether the former main collection point can be renovated and larger quantities of salt water can once again be collected above the installed liner. “The work is being carried out with the strictest safety precautions so as not to endanger the health of the miners,” explains Jürgen Korth, Technical Managing Director.

In order to work towards the end of the excavation, it is necessary to remove the gravel supporting material that was brought in decades ago, for example. This material was intended prevent large pieces of rock from falling from the ceiling. To further support the chamber ceiling, the miners are now erecting support structures consisting of concrete and steel girders.