ARD remediation with limestone in a CO_2 pressurized reactor

摘要

We evaluated a new process for remediation of acid rock drainage (ARD). The process treates ARD with intermittently fluidized beds of granular limestone maintained within a continuous flow reactor pressurized with CO_2. Tests were performed over a thirty day period at the Toby Creek mine drainage treatment plant, Elk County, Pennsylvania in cooperation with the Pennsylvania Departement of Environmental Protection. Equipment performance was established at operating pressures of 0, 34, 82, and 117 kPa using a ARD flow of 227 L/min. The ARD has the following characteristics: pH, 3.1; temperature, 10 deg C; dissolved oxygen, 6.4 mg/L; acidity, 260 mg/L; total iron; 21 mg/L; aluminum, 22 mg/L; manganese, 7.5 mg/L; and conductivity, 1400 mu S/cm.