Community Research and Development Information Service - CORDIS

New technology prevents environmental hazards from mines

The environmental impact of open cast mining can be devastating for a number of areas, especially when groundwater and waterworks are affected by the resulting acid drainage.
New technology prevents environmental hazards from mines
A German academic institution has devised a new method, which can be applied in mines across the EU and results in substantially lower pyrite oxidation levels and groundwater pollution. The mining process involves two distinct stages; the primary stage, during active mining and the secondary stage, taking place at the vegetated tip.

During the second stage, stored and soluble oxidation products can be leached from the dumping site and pollute groundwater even long after the mine has ceased operations. It is therefore imperative to limit this Acid Mine Drainage process in a time-efficient and environmentally sound manner.

The proposed technology aims to limit the effects of pyrite oxidation and improve the groundwater chemistry in the vicinity of mine areas. Although the primary stage appears unavoidable, Acid Mine Drainage occurring during the secondary oxidation process can be mitigated. The addition of crushed limestone to dump site was observed to lower the overall acidity.

The carbonate ions in the limestone act as chemical sponges, thus increasing pH values towards a neutral value. Pilot scale experiments involving the use of limestone resulted in neutral-pH environments combined with dramatic decreases in sulphate concentrations. The developers are now seeking industrial partners in a position to further this technology and apply it in similar settings.
Record Number: 82110 / Last updated on: 2005-09-18
Domain: Industrial Technologies