Tempel, R. N. (2000). A quantitative approach to optimize chemical treatment of acid drainage using geochemical reaction path modeling methods: Climax Mine, Colorado. ICARD 2000, Vols I and II, Proceedings, , 1053–1058.
Abstract: The Climax Mine, near Leadville, Colorado treats acid drainage in a lime neutralization chemical treatment system. Chemical treatment has been successful in reducing the concentration of metals to below surface water discharge effluent limits, but lime usage has not been optimized. A geochemical modeling approach has been developed to increase the efficiency of lime neutralization. The modeling approach incorporates two steps: (1)calibration, and (2) calculation of amount of lime needed to increase pH and remove metals. Results of our work quantify the lime treatment process and improve our ability to predict overall water quality.
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Zhuang, J. M. (2004). Lignor(TM) process for acidic rock drainage treatment. Environ. Technol., 25(9), 1031–1040.
Abstract: The process using lignosulfonates for acidic rock drainage (ARD) treatment is referred to as the Lignor(TM) process. Lignosulfonates are waste by-products produced in the sulfite pulping process. The present study has shown lignosulfonates are able to protect lime from developing an external surface coating, and hence to favor its dissociation. Further, the addition of lignosulfonates to ARD solutions increased the clotting and settling rate of the formed sludge. The capability of lignosulfonates to form stable metal-lignin complexes makes them very useful in retaining metal ions and thus improving the long-term stability of the sludge against leaching. The Lignor(TM) process involves metal sorption with lignosulfonates, ARD neutralization by lime to about pH 7, pH adjustment with caustic soda to 9.4 – 9.6, air oxidation to lower the pH to a desired level, and addition of a minimum amount of FeCl3 for further removal of dissolved metals. The Lignor(TM) process removes all concerned metals (especially Al and Mn) from the ARD of the Britannia Mine (located at Britannia Beach, British Columbia, Canada) to a level lower than the limits of the B.C. Regulations. Compared with the high-density sludge (HDS) process, the Lignor(TM) process has many advantages, such as considerable savings in lime consumption, greatly reduced sludge volume, and improved sludge stability.
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Sibrell, P. L. (2000). ARD remediation with limestone in a CO2 pressurized reactor. ICARD 2000, Vols I and II, Proceedings, , 1017–1026.
Abstract: We evaluated a new process for remediation of acid rock drainage (ARD). The process treats ARD with intermittently fluidized beds of granular limestone maintained within a continuous now reactor pressurized with CO2. Tests were performed over a thirty day period at the Toby Creek mine drainage treatment plant, Elk County, Pennsylvania in cooperation with the Pennsylvania Department of Environmental Protection. Equipment performance was established at operating pressures of 0, 34, 82, and 117 kPa using an ARD flow of 227 L/min. The ARD had the following characteristics: pH, 3.1; temperature, 10 OC; 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 muS/cm. In all cases tested, processed ARD was net alkaline with mean pH and alkalinities of 6.7 and 59 mg/L at a CO2 pressure of 0 kPa, 6.6 and 158 mg/L at 34 kPa, 7.4 and 240 mg/L at 82 kPa, and 7.4 and 290 mg/L at 117 kPa. Processed ARD alkalinities were correlated to the settled bed depth (p <0.001) and CO2 pressure (p <0.001). Iron, aluminum, and manganese removal efficiencies of 96%, 99%, and 5%, respectively, were achieved with filtration following treatment. No indications of metal hydroxide precipitation or armoring of the limestone were observed. The surplus alkalinity established at 82 kPa was successful in treating an equivalent of 1136 L/min (five-fold dilution) of the combined three ARD streams entering the Toby Creek Plant. This side-stream capability provides savings in treatment unit scale as well as flexibility in treatment effect. The capability of the system to handle higher influent acidity was tested by elevating the acidity to 5000 mg/L with sulfuric acid. Net alkaline effluent was produced, indicating applicability of the process to highly acidic ARD.
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Blowes, D. W. (1995). Treatment of mine drainage water using in situ permeable reactive walls. Sudbury '95 – Mining and the Environment, Conference Proceedings, Vols 1-3, , 979–987.
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Gemmell, R. P. (1981). The reclamation of acidic colliery spoil .2. The use of lime wastes. Journal of Applied Ecology, 18(3), 879–887.
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