Initial situation

LMBV has extensive experience of operating water treatment plant, an example of which is the Rainitza mine water treatment plant at the Meuro former opencast site near Großraschen. This treatment plant frees the water raised from the opencast pits from dissolved iron and particulates. The water's pH value must also be increased.

Approach

The Rainitza water treatment plant is able to treat 2,000 litres of mine water per second. The overall iron load of the raw water is reduced from five tonnes to half a tonne every day, while the water's pH value is raised from 4.5 to 8.0 by the daily addition of 78 m³ of slaked lime. After this treatment, while observing landscape and ecological requirements, the mine water is discharged into waters in the neighbourhood of the opencast mine.

Result

Between 2002 and 2006 a total of 187 million m³ of water was treated. After the water level of the mine has been lowered for operational reasons, mine water treatment plants usually perform long-term functions in the implementation of flooding plans. For example, at present, water undergoes intermediate treatment as it is raised from one set of former opencast pits and transferred to another. After flooding has been completed, the water treatment plants allow surplus water from former mine lakes to be treated so that it is in line with the limits for discharge.