Removal of dissolved contaminants from mine drainage

Eleven mill tailing samples from locations throughout the Rocky Mountain region were tested for their effectiveness in removal of dissolved contaminants from mine drainage . With the exception of the sample of the Blaine Mill tailing, the average capacity of the tailings tested was 9.8 mg of iron per gram of tailing with a range of capacities from 6 mg/g to 15 mg/g. In batch tests the Blaine mill tailing exhibited a capacity in excess of 100 mg of iron per gram of tailing. From these studies it was concluded that for all tailing samples, with the exception of the Blaine tailing , removal was accomplished mainly due to hydrolytic adsorption of metal ions with a small contribtion due to the inherent basicity of the tailing . In the case of the Blaine tailing , removal occurred via reaction with calcareous components of the sample. Continuous column, or stationary bed tests, in the laboratory and in the field were not nearly as effective . During the field test no aluminum was removed from the mine drainage and only 14 percent of the iron and copper were removed. During the test the pH rose from 2.85 to 3.5. It appears that for effective removal a stirred tank reactor will be required. If the results obtained in the batch test can be duplicated in the field, it is estimated that from 4.5 to 45.0 tons of tailing per day, depending on the capacity , would be required to remove iron from a mine drainage similar to the Gennesse. For a tailing similar to the Blaine tailing , approximately 200 lb of iron could be removed per ton of tailing,