Parker, G., Noller, B., & Waite, T. D. (1999). Assessment of the use of fast-weathering silicate minerals to buffer AMD in surface waters in tropical Australia. In D. E. Goldsack, N. Belzile, P. Yearwood, & G. J. Hall (Eds.), Sudbury '99; Mining and the environment II; Conference proceedings.
Abstract: Surface waters in the Pine Creek Geosyncline (located in Australia's “Top End”, defined as the area of Australia north of 15 degrees S) are characterized by their low carbonate buffering capacity. These waters are buffered by silicate weathering and hence are slightly acidic, ranging in pH from 4.0 to 6.0. The Pine Creek Geosyncline contains most of the Top Ends' economic mineral deposits and characteristically shows no correlation between carbonate minerals and sulfidic orebodies hosting gold deposits (unlike uranium deposits). Thus many gold mines do not have ready access to carbonate minerals for buffering acid mine drainage (AMD). It is possible that locally available fast-weathering silicate minerals may be used to buffer AMD seeps. The buffering intensity of silicate minerals exceeds that of carbonate minerals, but their slow dissolution kinetics has ensured that these materials have received little attention in treating AMD. In addition, carbonate mineral dissolution is retarded when contacted with intense AMD solutions due to the formation of surface coatings of iron minerals. The lower pH range of silicate mineral dissolution may prevent the formation of such coatings. The Pine Creek Geosyncline consists of a complex geochemistry, and a number of fast-weathering silicate minerals have been noted in various areas. The difficulty in assessing such minerals for use in buffering AMD is the lack of kinetic data available under conditions prevalent AMD (i.e., low pH solutions saturated with aluminium and silica). This study sets out to evaluate the applicability of using such minerals to treat AMD surface seeps.
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Miller, S. D. (1999). Overview of acid mine drainage issues and control strategies Remediation and management of degraded lands. In M. H. Wong, J. W. C. Wong, & A. J. M. Baker (Eds.),. Boca Raton: Lewis Publishers.
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Haferkorn, B., Mueller, M., Zeh, E., Benthaus, F. K., Pester, L., Lietzow, A., et al. (1999). Schaffung von Tagebauseen im mitteldeutschen Bergbaurevier; die Wiederherstellung eines sich selbst regulierenden Wasserhaushaltes in den Braunkohleabbaugebieten des Freistaates Sachsen (Nordwestsachsen), des Landes Sachsen-Anhalt und des Freistaates Thueringen. Creation of open-pit lakes in central Germany mining district; the reclamation of some self-regulating water balance in abandoned lignite regions of the Saxony Free States Northwest Saxony), of the Saxony-Anhalt state and Free States. Berlin: Lmbv.
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Benzaazoua, M., & Bussiere, B. (1999). Desulphurization of tailings with low neutralizing potential; kinetic study and flotation modeling. In D. Goldsack, N. Belzile, P. Yearwood, & G. Hall (Eds.), Sudbury '99; Mining and the environment II; conference proceedings.
Abstract: Environmental desulphurization is an attractive alternative for acid generating tailings management as demonstrated during the last few years. In fact, such process placed at the end of the primary treatment circuit allows to reduce greatly the amount of problematic tailings by concentrating the sulphidic fraction. Moreover, the desulphurized tailings (non-acid generating) have the geotechnical and environmental properties for being used as fine material in a cover with capillary barrier effects. To produce desulphurized tailings, non selective froth flotation is the most adapted method as shown in many previous works. Desulphurization level is fixed by tailings sulphur content (or sulphide content) and neutralization potential NP. The final residue should have enough NP to compensate for his acid generating potential AP. In this paper, the authors present the results of laboratory tests conducted in Denver cells for studying the sulphide flotation kinetics of four mine tailings which are characterized by a weak neutralization potential (under 37 kg CaCO (sub 3) /t). Tailings 1, 2, 3 and 4 contain respectively 5.27, 10, 4.25 and 16.9 sulphur Wt. %. Tailings 1 and 2 are cyanide free and are well floated at pH around 11 by using amyl xanthate as collector. Collector dosage was optimized for these tailings and the results show that Tailing 2 need more collector. However, Tailings 3 and 4, which come from a gold cyanidation process, could not provide good sulphide recovery with xanthate collector because of the pyrite depression. To overcome this problem, amine acetate was used successfully but induces important entrainment. The consumption of this collector was also optimized. The results of kinetic tests and collector dosage were combined and modeled to establish relationships which allow to estimate the desulphurization performances.
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Aube, B. C., & Zinck, J. M. (1999). Comparison of AMD treatment processes and their impact on sludge characteristics.
Abstract: Lime neutralisation for the treatment of acid mine drainage is one of the oldest water pollution control techniques practised by the mineral industry. Several advances have been made in the process in the last thirty years, particularly with respect to discharge concentrations and sludge density. However, the impact of different treatment processes on metal leachability and sludge handling properties has not been investigated. A study of treatment sludges sampled from various water treatment plants has shown that substantial differences can be related to the treatment process and raw water composition. This study suggests that sludge densities, excess alkalinity, long-term compaction properties, metal leachability, crystallinity and cost efficiency can be affected by the neutralisation process and specific process parameters. The study also showed that the sludge density and dewatering ability is not positively correlated with particle size as previously suggested in numerous studies. The treatment process comparisons include sludge samples from basic lime treatment, the conventional High Density Sludge (HDS) Process, and the Geco HDS Process.
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