| Abstract: | Thiobacilli may either attack coal-contained pyrite directly or contribute to its oxidation via catalysing the oxidation of ferrous salts by oxygen dissolved in water. The part played by either of the above mechanisms during pyrite removal from hard coals is discussed. This is followed by a review of experiments meant to identify the influence of coal rank, grain size, pyrite genesis and content, on pyrite removal efficiency over time. The paper reports on experiments to determine the seepage rate of the nutritive solution with bacteria, termed “biopulp”, in coal heaps. Investigations into the alteration of coal properties due to pyrite removal are dealt with. Concluding, plant dimensions and the costs of pyrite removal, as derived from two designs of relevant plants, are presented. |
