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Title: Solubility of Fe(III) and Al in AMD by modelling and experimtn

Conference ·
OSTI ID:126534
;  [1]
  1. Colorado School of Mines, Golden, CO (United States)

Studies of Fe(III) and Al species in acid mine drainage (AMD) alone and in contact with limestone were conducted by MINTEQA2 and by experiments. Using Fe(OH){sub 3} as the primary species and the standard values for MINTEQ, Fe(III) precipitates at pH 2.90 when the concentration is 453 mg/L. Al precipitates at a pH of 4.00 when the concentration is 108 mg/L. Experiments found that over 90 % of Fe(III) and 45 % of Al were precipitated at these pH`s. Experimental verification of Fe(III) concentrations at pH`s from 2.90 to 4.0 found that modelling agreed with experiment when ferrihydrite is the primary solid and the log Ksp is -38.9. For Al, gibbsite would be the primary solid and log Ksp is -34.1. For AMD in contact with CaCO{sub 3} when CO{sub 2} is conserved, final alkalinity is higher when mineral acidity is higher even though pH of the final solution is lower. This modelling result was confirmed by experiment. Higher mineral acidity causes generation of more CO{sub 2} that reacts with CaCO{sub 3} to generate more dissolved HCO{sub 3-}.

OSTI ID:
126534
Report Number(s):
CONF-950402-; TRN: 95:006086-0519
Resource Relation:
Conference: 209. American Chemical Society (ACS) national meeting, Anaheim, CA (United States), 2-6 Apr 1995; Other Information: PBD: 1995; Related Information: Is Part Of 209th ACS national meeting; PB: 2088 p.
Country of Publication:
United States
Language:
English