Water treatment

Uranium, radium, arsenic, iron, and manganese have to be removed from the water rising from the Schlema-Alberoda mine site to reach compliance with regulatory standards prior to discharge into the Zwickauer Mulde river. The water is pumped from the mine and fed to the Schlema-Alberoda water treatment plant for treatment. The plant consists of two nearly identical treatment lines which went on line at two years interval in 1998 and 2000.

The treatment plant has a design capacity of 1,150 m³ per hour. Water treatment residues are immobilised and the resulting crumbly product is then integrated into an engineered location at mine dump 371. Treatment of the mine water will have to continue until contaminant levels will be below regulatory standards to allow direct discharge into the receiving stream. Operation of the Schlema-Alberoda WTP is anticipated to be required for about 25 years.

 

The Pöhla water treatment plant came on line in 1995 to treat mine water emerging from the flooded Pöhla mine.

Uranium, radium, arsenic, iron, and manganese were separated by a number of selective precipitation techniques. With uranium concentrations in the flood water below regulatory discharge standards since 1997, uranium separation at this site was terminated.

Intensive investigations started in 1998 on alternative treatment methods for the mine water from the Pöhla pit using a pilot-scale plant. A passive/biological water treatment facility was commissioned in 2003. The facility treated ca. 15 to 20 m³/h mine water which was subsequently discharged via the Schildbach creek into the Luchsbach creek.

Since 2014 the flood water is treated in a new built Water treatment plant for its radium, arsenic and iron levels. Over time, uranium has decreased to low levels and does not henceforth need removal. Flood water quality is improving at a very slow rate thats why treatment will be required over an extended period of time.