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Kuyucak, N., Lindvall, M., Rufo Serrano, J. A., & Oliva, A. F. (1999). (R. Fernández Rubio, Ed.). Mine, Water & Environment. Ii: International Mine Water Association.
Abstract: Lime neutralization is a frequently used method in the mining industry for the treatment of acid waters. These waters contain metal ions such as zinc, manganese, copper, cadmium, lead, etc. The conventional, straight lime neutralization technology generates a Low Density Sludge (LDS) having only 1-2% solids content. This creates sludge disposal difficulties, and results in the loss of potentially large quantities of recovered water, which in turn increases the demand for fresh water requirements for mining/milling activities. The High Density Sludge (HDS) process, on the other hand, is the state-of-the-art technology in North America. It generates a dense sludge with less volume and better particulate properties. Furthermore, the typical gelatinous nature of the sludge changes to a granulated, sand-like texture. Boliden Apirsa, S.L. investigated the feasibility of an HDS process to increase the treatment capacity of their existing plant, and resolve the issues associated with the LDS process for their Los Frailes project. The project required, given that the production of ore was going to be doubled, a significant increase in water was needed without altering the water reservoir sitting north of the concentrator. In addition, the final effluent quality was a priority issue. First, a pilot-scale study was undertaken in 1996, and parameters critical to the design and performance of the process were determined. The results showed that the HDS process could significantly improve the sludge characteristics by increasing the solids fraction from 1.5 to 12.0%, thereby decreasing the sludge volume to be disposed to the tailings ponds by a factor of 10. A full-scale, HDS lime neutralization treatment plant for an average flow rate of 1500 m3/hr was designed and was commissioned in early 1998 in collaboration with Colder Associates, Ottawa, Canada. So far, the full-scale treatment plant has been generating a sludge with more than 30% solids content, exceeding its target value of 12% solids. It produces excellent effluent quality, and scaling in the handling equipment is virtually eliminated. The sludge has dense, easily settable granular particles rather than fluffy flocs, yet has low viscosity that facilitates its unassisted gravity flow. The process has resulted in an increase in the treated water volume. The rate of lime consumption per unit volume of water treated also decreased. The process principles and the steps taken in process development will be discussed and the results obtained to date will be summarized in this communication.
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Bamforth, S. M. (2006). Manganese removal from mine waters – investigating the occurrence and importance of manganese carbonates. Appl. Geochem., 21(8), 1274–1287.
Abstract: Manganese is a common contaminant of mine water and other waste waters. Due to its high solubility over a wide pH range, it is notoriously difficult to remove from contaminated waters. Previous systems that effectively remove Mn from mine waters have involved oxidising the soluble Mn(II) species at an elevated pH using substrates such as limestone and dolomites. However it is currently unclear what effect the substrate type has upon abiotic Mn removal compared to biotic removal by in situ micro-organisms (biofilms). In order to investigate the relationship between substrate type, Mn precipitation and the biofilm community, net-alkaline Mn-contaminated mine water was treated in reactors containing one of the pure materials: dolomite, limestone, magnesite and quartzite. Mine water chemistry and Mn removal rates were monitored over a 3-month period in continuous-flow reactors. For all substrates except quartzite, Mn was removed from the mine water during this period, and Mn minerals precipitated in all cases. In addition, the plastic from which the reactor was made played a role in Mn removal. Manganese oxyhydroxides were formed in all the reactors; however, Mn carbonates (specifically kutnahorite) were only identified in the reactors containing quartzite and on the reactor plastic. Magnesium-rich calcites were identified in the dolomite and magnesite reactors, suggesting that the Mg from the substrate minerals may have inhibited Mn carbonate formation. Biofilm community development and composition on all the substrates was also monitored over the 3-month period using denaturing gradient gel electrophoresis (DGGE). The DGGE profiles in all reactors showed no change with time and no difference between substrate types, suggesting that any microbiological effects are independent of mineral substrate. The identification of Mn carbonates in these systems has important implications for the design of Mn treatment systems in that the provision of a carbonate-rich substrate may not be necessary for successful Mn precipitation. (c) 2006 Elsevier Ltd. All rights reserved.
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Juby, G. J. G., & Schutte, C. F. (2000). Membrane Life in a Seeded-slurry Reverse Osmosis System. Water Sa, 26(2), 239–248.
Abstract: Membrane replacement can be a major operating cost of a membrane plant. During the development of a novel desalination technique (the SPARRO process) for treating calcium sulphate scaling mine waters the expected life of tubular cellulose acetate membranes operating in the seeded-slurry mode was investigated.During four operating phases of the plant over a five-year period more than 9 000 h of operating data were obtained. Performance data showed that each operating phase was dominated by either membrane fouling or membrane hydrolysis. Membrane fouling was observed to begin near the front-end of the membrane stack and proceed towards the back. Hydrolysis, on the other hand, occurred first in the tail end of the stack and moved backwards towards the Front end modules. Although two detailed membrane autopsies were carried out no definitive statement can be made in respect of the causes of either membrane hydrolysis or membrane fouling. However, suggestions are presented to explain the observed fouling phenomenon in relation to the turbidity of the pretreated feed water and the presence of chlorine. It is proposed that the presence of radioactive isotopes in the mine water which become concentrated in the process contributes to the observed membrane hydrolysis. A membrane life of up to two years is projected for an improved pretreatment arrangement.
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Edraki, M. (2006). Post closure management of the Mt Leyshon Gold Mine – Water the integrator. Water in Mining 2006, Proceedings, , 233–242.
Abstract: Mining at the Mt Leyshon Gold Mine in semi-arid north Queensland stopped in 2002. Newmont Australia has recently initiated a thorough post-closure water management study of the site by revisiting the existing information and conducting new water-related investigations. The focus of this paper. which is the first publication on post-closure environmental management of the site. is an overview of the site water quality in view of the sources and spatial distribution of polluted mine water, and also the performance of cover systems in controlling water flux though mine wastes.
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Wolkersdorfer, C. (2006). Tracer tests as a mean of remediation procedures in mines. Uranium in the Environment: Mining Impact and Consequences, , 817–822.
Abstract: Mining usually causes severe anthropogenic changes by which the ground- or surface water might be significantly polluted. One of the main problems in the mining industry are acid mine drainage, the drainage of heavy metals, and the prediction of mine water rebound after mine closure. Consequently, the knowledge about the hydraulic behaviour of the mine water within a flooded mine might significantly reduce the costs of mine closure and remediation. In the literature, the difficulties in evaluating the hydrodynamics of flooded mines are well described, although only few tracer tests in flooded mines have been published so far. Most tracer tests linked to mine water problems were related to either pollution of the aquifer or radioactive waste disposal and not the mine water itself.
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