초록 ▼

Acid drainage from exposed pyritic material such as coal mine tailings is reduced through the controlled application of anionic detergents which inhibit the bacterium Thiobacillus ferrooxidans. The controlled application of anionic detergent comprises an initial application of anionic detergent in s

Acid drainage from exposed pyritic material such as coal mine tailings is reduced through the controlled application of anionic detergents which inhibit the bacterium Thiobacillus ferrooxidans. The controlled application of anionic detergent comprises an initial application of anionic detergent in sufficient quantities to satisfy the adsorptive capacity of clay or clay-sized particles overlying the pyritic material coupled with the application of an anionic detergent inhibitor of Thiobacillus ferrooxidans from a slow release matrix containing the inhibitor. The two applications are to intercept infiltrating water up-gradient of the pyritic material or strata. The amount of matrix employed is calculated in accordance with a described formula. The method can be used to reduce acidity in drainage from pyritic mine tailings, coal mines, coal refuse piles and construction sites at which acid drainage is a problem. Acid drainage is also reduced by the mere controlled application of specific anionic detergents which inhibit the bacterium Thiobacillus ferrooxidans utilizing a detergent-containing matrix which provides detergent concentrations of greater than 10 ppm and preferably greater than 25 ppm in the infiltrating water.

대표청구항 ▼

A method of reducing acid drainage in a pyritic material which is exposed to water, which method comprises: (1) treating each acre-foot of pyritic material with at least seven pounds of a first anionic detergent which inhibits the bacterium Thiobacillus ferrooxidans; and (2) adding at least 10 mg of

A method of reducing acid drainage in a pyritic material which is exposed to water, which method comprises: (1) treating each acre-foot of pyritic material with at least seven pounds of a first anionic detergent which inhibits the bacterium Thiobacillus ferrooxidans; and (2) adding at least 10 mg of a second anionic detergent which inhibits the bacterium Thiobacillus ferrooxidans per liter of said water which contacts the exposed material, said addition being effected by controlled release from a matrix containing said second anionic detergent dispersed therein; said first and second anionic detergent being selected from the group consisting of Thiobacillus ferrooxidans-inhibiting water soluble salts of (a) alkyl aryl sulfonic acids, (b) alkyl sulfonic acids, (c) alkenyl sulfonic acids, (d) sulfated fatty esters.