SHORT-TERM ACID ROCK DRAINAGE CHARACTERISTICS DETERMINED BY PASTE pH AND KINETIC NAG TESTING: CYPRESS PROSPECT, NEW ZEALAND

Weber, Paul; Hughes, Joseph B.; Conner, Liam B.; Lindsay, P.; St, Roger; Smart, C. C.

doi:10.21000/jasmr06022289

Cited by 37 publications

(37 citation statements)

References 8 publications

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“…For acid formation potential, the paste pH test is one of method used to determine the acidic nature of a rock/soil sample (Weber et al 2006). Although the paste pH is an instant measurement of acidity or alkalinity of the sample but it cannot provide quantitative result.…”

Section: Sampling and Analytical Methodsmentioning

confidence: 99%

“…Although the paste pH is an instant measurement of acidity or alkalinity of the sample but it cannot provide quantitative result. The test was prepared by 1 g powder sample mixed with 20 ml deionized water, and then tested with a pH probe after 1 h. The paste pH results would initially indicate potential of acid mine drainage (Sobek et al 1978;Noll et al 1988;Weber et al 2006); however, quantitative static methods must be carried out to confirm this.…”

Section: Sampling and Analytical Methodsmentioning

confidence: 99%

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Chemical characteristics and acid drainage assessment of mine tailings from Akara Gold mine in Thailand

et al. 2009

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Acid Mine Drainage (AMD) is a great concern in many abandoned mines because of its adverse effect on the environment. In mining processes, many kinds of wastes are produced. These wastes may become eventually sources of environmental degradation. The focus of this study is the geochemical characterization of the end-processed tailings generated by Akara Gold Mine, the biggest gold mine in Thailand. Tailing samples were systematically collected for analyses of chemical and mineralogical compositions. As a result, their quantitative chemical analyses are slightly different from place to place, but mineral components cannot be clearly differentiated. For instance, it may be assumed that the end-processed tailings, which were a mixture between high and low grade concentrates, would have similar mineral components. However, the little variation of chemical composition may be caused by the ore refining processes that are somehow varied in proportion to chemical additives, alkali cyanide and quick lime in particular. In addition, clay composition in ore-bearing layers may also influence alumina content of tailings, accordingly. Distribution of the tailings is not related to depth and distance of the tailing storage pond because the disposal has sped them over the pond during operation. Total heavy metals of the tailing samples were analyzed on the basis of the EPA 3052 method. Consequently, the most toxic elements (e.g., Co, Cu, Cd, Cr, Pb, Ni and Zn) were found falling within the standard of Thailand Soil Quality Standards for Habitat and Agriculture. Only Mn appears to have higher content than the standard. In addition, leaching tests proved that these tailings contain low metal concentrations. As a result, at pH 2, Mn can leach out exceeding the Thailand Surface Water Quality Standard for Agricultural (Mn \1 ppm) and the Thailand Industrial Effluent Standard (\5 ppm). Although leachate at pH 4 and neutral conditions contains lower Mn than the Industrial Effluent Standard it still exceeds the surface water quality standard. Interestingly, Pb can be leached out exceeding both standards (0.2 ppm for the industrial effluent standard and 0.05 ppm for the surface water quality standard). For Ni leaching, its concentration is lower than the Industrial Effluent Standard at all pH conditions but still exceeds the Surface Water Standard at pH 2 and 4. This information should be taken into consideration for further environmental monitoring. Acid generating potential of the tailings was estimated using acid-base accounting (ABA) and net acid generation (NAG) tests. The results of ABA and NAG tests show that the tailing samples contain a high amount of sulfur. However, they also contain high acid neutralization capacity. Consequently, these tailings may not have potential to generate acid drainage; in the other words, they can be classified as a non-acid forming (NAF) material. However, since these tailings contain some heavy metals

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Section: Sampling and Analytical Methodsmentioning

confidence: 99%

Section: Sampling and Analytical Methodsmentioning

confidence: 99%

Chemical characteristics and acid drainage assessment of mine tailings from Akara Gold mine in Thailand

et al. 2009

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“…Paste pH was analyzed in duplicate with a pH meter (Metrohm Ltd., 704 pH Meter, Herisau, Switzerland) for all four batches of GLD according to Weber et al [23].…”

Section: Physical Characterizationmentioning

confidence: 99%

Characterization of Green Liquor Dregs, Potentially Useful for Prevention of the Formation of Acid Rock Drainage

et al. 2014

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Abstract:Using alternative materials such as residual products from other industries to mitigate the negative effects of acid rock drainage would simultaneously solve two environmental problems. The main residual product still landfilled by sulphate paper mills is the alkaline material green liquor dregs (GLD). A physical, mineralogical and chemical characterization of four batches of GLD was carried out to evaluate the potential to use it as a sealing layer in the construction of dry covers on sulphide-bearing mine waste. GLD has relatively low hydraulic conductivity (10 −8 to 10 −9 m/s), a high water retention capacity (WRC) and small particle size. Whilst the chemical and mineralogical composition varied between the different batches, these variations were not reflected in properties such as hydraulic conductivity and WRC. Due to relatively low trace element concentrations, leaching of contaminants from the GLD is not a concern for the environment. However, GLD is a sticky material, difficult to apply on mine waste deposits and the shear strength is insufficient for engineering applications. Therefore, improving the mechanical properties is necessary. In addition, GLD has a high buffering capacity indicating that it could act as an alkaline barrier. Once engineering technicalities have been overcome, the long-term effectiveness of GLD should be studied, especially the effect of aging and how the sealing layer would be engineered in respect to topography and climatic conditions.

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“…The FLT is effective because it rapidly dissolves these readily soluble phases providing a snapshot of the net or ''weathering'' ABA of the mine waste materials. Whereas other studies Weber et al, 2006) have previously shown that pH results from the paste test provide indication of short-term ABA potential of a mine waste sample, this study provides data showing that the use of either paste pH or 5-min FLT pH are effective at predicting not only the short-term, but also the long-term ABA behavior of weathered metal mining waste.…”

Section: Acid-base Accounting Resultsmentioning

confidence: 51%

Evaluation of selected static methods used to estimate element mobility, acid-generating and acid-neutralizing potentials associated with geologically diverse mining wastes

Hageman

Seal

Diehl

et al. 2015

Applied Geochemistry

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a b s t r a c tA comparison study of selected static leaching and acid-base accounting (ABA) methods using a mineralogically diverse set of 12 modern-style, metal mine waste samples was undertaken to understand the relative performance of the various tests. To complement this study, in-depth mineralogical studies were conducted in order to elucidate the relationships between sample mineralogy, weathering features, and leachate and ABA characteristics. In part one of the study, splits of the samples were leached using six commonly used leaching tests including paste pH, the U.S. Geological Survey (USGS) Field Leach Test (FLT) (both 5-min and 18-h agitation), the U.S. Environmental Protection Agency (USEPA) Method 1312 SPLP (both leachate pH 4.2 and leachate pH 5.0), and the USEPA Method 1311 TCLP (leachate pH 4.9). Leachate geochemical trends were compared in order to assess differences, if any, produced by the various leaching procedures. Results showed that the FLT (5-min agitation) was just as effective as the 18-h leaching tests in revealing the leachate geochemical characteristics of the samples. Leaching results also showed that the TCLP leaching test produces inconsistent results when compared to results produced from the other leaching tests. In part two of the study, the ABA was determined on splits of the samples using both well-established traditional static testing methods and a relatively quick, simplified net acid-base accounting (NABA) procedure. Results showed that the traditional methods, while time consuming, provide the most in-depth data on both the acid generating, and acid neutralizing tendencies of the samples. However, the simplified NABA method provided a relatively fast, effective estimation of the net acid-base account of the samples. Overall, this study showed that while most of the wellestablished methods are useful and effective, the use of a simplified leaching test and the NABA acid-base accounting method provide investigators fast, quantitative tools that can be used to provide rapid, reliable information about the leachability of metals and other constituents of concern, and the acidgenerating potential of metal mining waste.Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

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SHORT-TERM ACID ROCK DRAINAGE CHARACTERISTICS DETERMINED BY PASTE pH AND KINETIC NAG TESTING: CYPRESS PROSPECT, NEW ZEALAND

Cited by 37 publications

References 8 publications

Chemical characteristics and acid drainage assessment of mine tailings from Akara Gold mine in Thailand

Chemical characteristics and acid drainage assessment of mine tailings from Akara Gold mine in Thailand

Characterization of Green Liquor Dregs, Potentially Useful for Prevention of the Formation of Acid Rock Drainage

Evaluation of selected static methods used to estimate element mobility, acid-generating and acid-neutralizing potentials associated with geologically diverse mining wastes

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