Abstract

MARTINEZ, Edgar Alberto; TOBON, Jorge Iván  and  MORALES, Juan Guillermo. Coal acid mine drainage treatment using cement kiln dust. Dyna rev.fac.nac.minas [online]. 2014, vol.81, n.186, pp.87-93. ISSN 0012-7353.  https://doi.org/10.15446/dyna.v81n186.38834.

Sulphurs are present in different rocks. During mining activities and the sulphur removal processes Acid Mine Drainage (AMD) may be produced, by sulphate ions (SO₄^2-) in solution. AMDs are the main source of pollution from mining operations and in Colombia their discharge into natural bodies of water must comply with national environmental regulations (pH between 5 and 9). Cement Kiln Dust (CKD), with calcium carbonate as its main component, from a Cementos Argos S.A. plant was used to neutralize an AMD generated through a coal bio-desulphurization process. Neutralized AMDs had pH values between 7.72 - 8.05 and the sulphates removal ranged from 67% to 70%. Precipitated sludge was dried and analyzed in order to determine its chemical and mineralogical composition. Moisture content was between 69% and 81%; this precipitated material was composed of gypsum with approximately 50% purity, as well as calcium carbonate. This composition makes it suitable for use in cement production.

Keywords : Acid Mine Drainage; Sulphate Removal; Cement Kiln Dust; Synthetic Gypsum.

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