Mine water treatment

Mine water from lignite mining is often characterised by an acidic pH value and high iron and sulfate concentrations. Before discharge into the receiving water body, this water must be treated. In most cases, an effluent concentration of <3 mg/l is required for iron.

A proven chemical process is frequently used for mine water treatment. This essentially involves raising the pH value through the addition of lime, as well as targeted oxidation of iron followed by flocculation and sedimentation.

The proven OxyStar® aerators in a heavy-duty design are used for this purpose. If the mine water contains a high level of free carbon dioxide, a physical desorption stage can be installed upstream of the chemical stage. Targeted stripping of CO₂ with AeroStar aerators then saves significant quantities of neutralising agents in the subsequent chemical stage and noticeably reduces operating costs.