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Catalan, L. J. J., & Yin, G. (2003). Comparison of calcite to quicklime for amending partially oxidized sulfidic mine tailings before flooding. Environ Sci Technol, 37(7), 1408–1413.
Abstract: Flooding partially oxidized mine tailings for the purpose of mitigating further oxidation of sulfide minerals and generation of acid drainage is generally preceded by treatment with alkaline amendments to prevent releasing previously accumulated acidity to the water cover. This work compares the ability of calcite (CaCO3) and quicklime (CaO), two common amendments, to establish and maintain pH conditions and dissolved metal concentrations within environmentally acceptable ranges over long time periods. Although higher initial pH values were obtained with quicklime, the pH of quicklime treated tailings decreased over time. This was attributed to the low buffering capacity of quicklime treated tailings and to the consumption of hydroxide ions by incongruent dissolution of water-insoluble iron oxyhydroxysulfate minerals. In contrast, the pH of tailings treated with calcite increased initially and then remained stable at pH approximate to 6.7. This pH behavior was due to the lower reactivity of iron oxyhydroxysulfates with calcite, the increased buffering capacity provided by bicarbonate ions, and the incomplete dissolution of calcite. Overall, calcite was found preferable to quicklime for maintaining long-term neutral pH conditions in the treated tailings. With the exception of zinc, acceptable dissolved metal concentrations were achieved with calcite treated tailings.
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Chalaturnyk, R. J., Scott, J. D., & Ozum, B. (2002). Management of Oil Sands Tailings. Pet. Sci. Technol., 20(9-10), 1025–1046.
Abstract: In Alberta, oil sands bitumen is utilized for synthetic crude oil (SCO) production by surface mining, bitumen extraction followed by primary (coking) and secondary (catalytic hydro-treating) upgrading processes. SCO is further refined in specially designed or slightly modified conventional refineries into transportation fuels. Oil sands tailings, composed of water, sands, silt, clay and residual bitumen, is produced as a byproduct of the bitumen extraction process. The tailings have poor consolidation and Water release characteristics. For twenty years, significant research has been performed to improve the consolidation and water release characteristics of the tailings. Several processes were developed for the management of oil sands tailings, resulting in different recovered water characteristics, consolidation rates and consolidated solid characteristics. These processes may affect the performance of the overall plant operations. Apex Engineering Inc. (AEI) has been developing a process for, thesame purpose. In this process oil sands tailings are treated with Ca(OH)(2) lime and CO2 and thickened using a suitable thickener. The combination of chemical treatment and the use of a thickener results in the release of process water in short retention times without accumulation of any ions in the recovered water. This makes it possible to recycle the recovered water, probably after a chemical treatment, as warm as possible, which improves the thermal efficiency of the extraction process. The AEI Process can be applied in many different fashions for the management of different fractions of the tailings effluent, depending on the overall plant operating priorities.
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Chen, M., Li, L., Grace, J., Tazaki, K., Shiraki, K., Asada, R., et al. (2007). Remediation of acid rock drainage by regenerable natural clinoptilolite. Water, Air, Soil Pollut., 180(1-4), 11–27.
Abstract: Clinoptilolite is investigated as a possible regenerable sorbent for acid rock drainage based on its adsorption capacity for Zn, adsorption kinetics, effect of pH, and regeneration performance. Adsorption of Zn ions depends on the initial concentration and pH. Adsorption/Desorption of Zn reached 75% of capacity after 1-2 h. Desorption depended on pH, with an optimum range of 2.5 to 4.0. The rank of desorption effectiveness was EDTAEDTA > NaCl > NaNO3 > NaOAc > NaHCO3 > Na2CO3 > NaOH > CeCa(OH)(2). For cyclic absorption/desorption, adsorption remained satisfactory for six to nine regenerations with EDTA and NaCl, respectively. The crystallinity and morphology of clinoptilolite remained intact following 10 regeneration cycles. Clinoptilolite appears to be promising for ARD leachate treatment, with significant potential advantages relative to current treatment systems.
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Cheng, S. - Y. (1976). Reclamation of acid mine water by coupled ion exchange-reverse osmosis. Ph.D. thesis, West Virginia University,, .
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Chironis, N. P. (1987). Mine-built ponds economically clear acid mine waters. Coal Age, (1), 58–61.
Abstract: Bestimmte Wasserpflanzen in Teichen können Metalle aus sauren Grubenwässern binden durch Adsorption, Filtration und Einlagerung in Wurzeln und Blättern. Algen und oxydierende Bakterien unterstützen diesen Reinigungsprozeß. Angaben zur Anlage der Teiche: Durchflußkapazität 20 l/min bis 38 l/min, Spülung von 18 m(exp 2) pro 4 l Durchflußmenge, Wasserhöhe 5 cm bis 10 cm, der pH-Wert des austretenden Wassers ist größer als 4,0.
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