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Browsing Conference Publications by Subject "Acid mine drainage"

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    Crocodile bones as archives of pollution exposure: lead contamination in Kakadu National Park, and what's in Sweetheart's Osteoderms?
    (Australian Nuclear Science and Technology Organisation, 2001-08-23) Jeffree, RA; Markich, SJ; Hammerton, KM; Russell, RA
    Experimental findings made it then possible to evaluate the hypothesis that the estuarine crocodile osteodermal laminations would record enhanced blood lead concentrations resulting from the ingestion of lead shot. At about 140 days following lead shot ingestion, two osteoderms were removed from each exposed and control animal. SIMS analysis of Pb-208 and Ca-42 signal intensities was then performed on sections that were prepared and analysed using similar methods previously used on field-collected specimens (Twining et al., 1999). These initial findings are consistent with the hypothesis that incremental laminations of the osteoderm will archive a lead signal that responds to enhanced levels of lead in the animal's blood during its life. SEM analysis identified the laminated structure of the osteoderm, however microprobe analysis did not detect appreciable amounts of even Ca and P, although the organic matrix was obviously present. It is proposed that this anomalous result is due to the preparatory tanning of the skin, in acid solution, that could be expected to leach elements from the organic matrix. An analogy is drawn with the decalcified skeletons in the bodies of the Druid sacrifices due their deposition in acid swamp waters in the UK. The challenge is now to sample osteoderms from large crocodiles in the Finniss River, preferably in close proximity to the Rum Jungle mine site, where any archived pollution signal would be more intense, and then repeat this analytical investigation of the osteodermal history of contaminant loadings. © 2002 Commonwealth of Australia
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    From Rum Jungle to Wismut - Reducing the environmental impact of uranium mining and milling
    (The Institution of Engineers Australia, 1994-05-01) Zuk, WM; Jeffree, RA; Levins, DM; Lowson, RT; Ritchie, AIM
    Australia has a long history of uranium mining. In the early days, little attention was given to environmental matters and considerable pollution occurred. ANSTO has been involved in rehabilitation of a number of the early uranium mining sites, from Rum Jungle in Australia's Northern Territory to Wismut in Germany, and is working with current producers to minimise the environmental impact of their operations. ANSTO's expertise in amelioration of acid mine drainage, radon measurements and control, treatment of mill wastes, management of tailings, monitoring of seepage plumes, mathematical modelling of pollutant transport and biological impacts in a tropical environment are summarized.
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    Kinetics of coupled Fe(II)-catalysed ferrihydrite transformation and U(VI) reduction
    (Mineralogical Society of Greate Britian & Ireland, 2011-10-01) Boland, DD; Collins, RN; Glover, CJ; Payne, TE; Waite, TD
    Antimony is released into the environment in some natural and man-induced processes. [1]. Yet, its impact on the transformation processes of heavy metal-adsorbing minerals remains poorly understood. In acid-mine drainage systems and shooting ranges, the adsorption of antimony by iron oxides such as ferrihydrite can play a major role. The poorly crystalline 2-line ferrihydrite represents one of the most common Fe oxides in these settings and can transform to goethite (,-FeOOH) or hematite (,-Fe2O3) with time [2]. The rate of transformation depends on the pH, temperature, and on the ions and molecules present during the transformation process [3]. This study focuses on the transformation of synthetic ferrihydrite to crystalline iron oxides in the presence of Sb(V). Transformations were carried out for 1-16 days at 70 ºC and at pH 4, 7 and 12, with different concentrations of Sb(V) (0.00, 0.23, 0.75, 2.25 and 6.00 mM Sb). Samples taken from aqueous suspensions were washed, dried, and characterized by X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS). At pH 12, goethite (Sb concentrations up to 3.7 mg Sb/g) is favored and the transformation is completed after one day. Only a concentration of 6 mM Sb retarded the transformation, where even after 8 days only 50 % of the ferrihydrite was transformed into goethite. Transformations at pH 7 led to a mixture of 75 % hematite and 25 % goethite (4.3 mg Sb/g). However, at concentrations of 6 mM Sb, feroxyhyte (!-FeOOH) (9.1 mg Sb/g) was favored instead. At pH 4, hematite (32.3 mg Sb/g) was favored except for concentrations of 6 mM Sb, were again feroxyhyte (141.1 mg Sb/g) occurred. We assume that increased Sb concentrations favor feroxyhyte and indicate the incorporation of Sb into the structure of feroxyhyte. © The Authors
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    Management and quantification of the impact of acid rock drainage
    (Royal Australian Chemical Institute & Australasian Society of Ecotoxicology, 2002-07-21) Brown, PL
    Acid rock drainage from sulfidic waste piles is recognised as one of the most significant problems facing the global mining industry, costing the industry billions of dollars annually. Acid drainage affects all sectors of the industry including coal, precious metals, base metals, iron ore and uranium. A number of government and industry initiatives have been formed to combat the problem. These initiatives have focused on the development of scientifically-based technologies for the management of wastes, resulting in a reduction (or minimisation) of the potential for ecological / environmental risk. This presentation will outline some of the best practice tools and techniques developed to quantify and manage acid rock drainage. It will provide an overview of the quantification of the effectiveness of control measures, determination of the level of acceptance ecological impact and appropriate means of measuring this in the field, what is required for prediction of impact and effluent quality and over what time frame realistic predictions can be made. It will also examine the implementation of management strategies through the mining life cycle. © The Authors.