| Popis: |
The water quality characteristics of a coal slurry were found to vary widely, depending upon the coal used and the use of a corrosion inhibitor. The coal-water interactions were evaluated in a pilot-plant closed-loop coal slurry pipeline. Pulverized coal from eastern Kentucky and tap water were slurred and pumped through a 40 foot (12.2 m) pipe loop for ten days. Slurry samples were collected at 3 hours, 7 hours, 1 day, 2 days, 4 days, 7 days and 10 days from the start of a run. The samples were filtered and analyzed for 29 water quality parameters, including 15 metals. Two runs were performed without adding a corrosion inhibitor and two runs were performed with the addition of a corrosion inhibitor. The coal slurry filtrate contained high levels of sulfates, total dissolved solids, conductivity, acidity, iron, magnesium, manganese, lead and aluminum. The pH dropped initially, depending upon the percent sulfur in the dry coal and the alkalinity in the slurry, but returned to 6-7 after 10 days in the pipeline. Metal concentrations were a function of the pH, which affected solubility. Organics in the filtrate were at low levels. The addition of a corrosion inhibitor increased the concentrations of most parameters. |
