INFLUENCE OF PH AND OXIDATION-REDUCTION POTENTIAL (EH) ON THE DISSOLUTION OF MERCURYCONTAINING MINE WASTES FROM THE SULFUR BANK MERCURY MINE

摘要

This study was undertaken as a part of developing treatmentalternatives for waste materials, primarily waste rock and roastertailings, from sites contaminated with mercury (Hg) mining wastes.Leaching profiles of waste rock over a range of different pH andoxidation-reduction (Eh) conditions were performed. Since iron (Fe) ispresent in large quantities in mining wastes, the effect of Fe onleaching of Hg was also determined. Results show that the Hgconcentration increased as the pH of the suspension increased untila pH value of 10.65. Thereafter, the Hg concentration decreasedsharply. The Hg concentration, in presence of Fe decreasedsignificantly (1/10th to 1/100th). Kinetics results show a relatively slowrate of leaching in presence of ferric ions. The results obtained fromthe present study are being used to predict the fate and stability of Hgpresent in the environment, and will therefore, be useful in dictatingthe nature and suitability of any remediation treatment.