Column Leach Study IV Factors Affecting the Dissolution of Metals from Sulfidic Metal-mine Tailings.
Proceeds 2nd Int'l Conf on Abatement of Acidic Drainage Quebec Canada 2:115-138
The factors influencing the dissolution and transport of metals in sulfidic metal-mine tailings have been extensively studied in U.S. Bureau of Mines laboratories. The composition and amount of primary and secondary minerals in waste were found to be of major importance. Other significant factors were the availability of oxygen; amount of pore water; leachant ph, ionic strength, and type of ions present; leachate contact time (residence time); depth of tailings; volume of leachant per leaching; pore water evaporation rate and degree of saturation; and dry tailings "storage" time and humidity. Even though a tailings sample contained considerable amounts of oxidizable sulfidic minerals, dissolution from columns of saturated tailings was independent of residence time and showed little dependence on column depth. Metal concentrations showed a direct dependence on residence time and column depth when the columns went through a dry (unsaturated) cycle. The effects of these factors on metal dissolution and transport are discussed.
Proceeds 2nd Int'l. Conf. on Abatement of Acidic Drainage, Quebec, Canada, V. 2, PP. 115-138