Global Advantech’s system for the treatment of acid mine water removes sulphates and other cations in water discharges from working and abandoned mines and other industrial works. These cations both contribute to acidity and solubilise heavy metals into solution, making these discharges hazardous to the environment.
The acidity in mine discharge water is mainly produced by the oxidation of sulphide minerals, in particular iron pyrite (iron disulphide - FeS2), when they are exposed to oxygen in the air and water. This reaction of pyrite with oxygen and water produces a solution of ferrous sulphate and sulphuric acid. These ferrous irons may undergo oxidation to ferric ions, increasing acidity still further. Additionally, iron and sulphur oxidising bacteria are known to catalyse these chemical reactions at low pH and are therefore capable of increasing oxidation reaction rates by several orders of magnitude over natural oxidation processes. This resultant acidity then solubilises metals into the water, which is discharged.
Global Advantech’s treatment systems combine chemical conditioning with electrocoagulation treatment to remove sulphate and carbonate cations, heavy metals and suspended solids, whilst minimising the production of waste by-products. Global Advantech has a patent pending on the process.
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