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首页> 外文学位 >Evaluation du comportement geochimique en conditions normale et froides de differents steriles presents sur le site de la mine Raglan.
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Evaluation du comportement geochimique en conditions normale et froides de differents steriles presents sur le site de la mine Raglan.

机译：Raglan矿场中存在的各种废石在正常和寒冷条件下的地球化学行为评价。

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摘要

The objective of this project is to characterize the geochemical behaviour of different waste rock types, with no mineralogical influence of the deposit, in normal (laboratory) and cold conditions. We aim at improving our knowledge concerning the phenomena involved in the generation or attenuation of an eventual water contamination, and to evaluate the influence of temperature on these phenomena. To do so, seven samples of representative waste rock were selected, each of them representing a different geology. Kinetic and oxygen consumption column tests were performed on the samples (70 kg) at normal temperature to determine the contamination potential of the waste rocks. Other tests at smaller scale, in weathering cells (67 g), were performed to assess the effect of temperature on their geochemical behaviour. This test is more aggressive than the column test and therefore allows better observing geochemical changes.;Alteration cells showed that the oxidation rates of sulphides and silicate dissolution decrease with a temperature reduction, and can be properly predicted by the Arrhenius law. A low sulphate leaching is observed for 5 of the 7 rock types at -6°C, suggesting low sulphide oxidation at this temperature. Calcium is leached in larger quantity at lower temperatures (10°C and -6°C) than at normal temperature because of an increase in calcite reactivity (present in traces); this dissolution increase would be in response to the acidity produced by the dissolving atmospheric CO2, that is higher at lower temperatures. Calcium leaching increases at cold temperatures as reflected by the ratio of the chemical elements related to the neutralizing minerals (especially Ca+Mg) and the sulphate production related to sulphide oxidation. Freeze/thaw cycles yielded higher sulphide oxidation rates and iron leaching. When comparing the different leaching rates obtained in the study, we note that there are scale-up effects between the columns and the weathering cells, and that there is also a temperature effect. However, it is impossible to use a single relationship to extrapolate the leaching rates for all the chemical elements from one scale or temperature to another scale or temperature.;Based on the results of this study, we therefore recommend to Raglan mine to manage the waste rocks with a short term CND potential with the potentially acid generating waste rocks, and to prioritize them as underground rockfill, or filling the bottom of open pits to facilitate their integration to the permafrost and reduce their reactivity. The materials with no acid generating potential and only a long term CND potential could be stored at the surface for a longer period and even be used for rehabilitation (for example as cover materials for the waste rock in open pits or tailings stack). Thus, the production of contamination on site and the costs related to water treatment and rehabilitation could be reduced during the mine operations. (Abstract shortened by UMI.);Column tests showed that six of the seven waste rock types are not potentially acid generating (PAG). The acid generating potential of the olivine-pyroxenite from mine 3 is uncertain. In the waste rocks, the acidity can be produced by sulphide oxidation; the main sulphide minerals present in the waste rocks are pyrrhotite, pentlandite, pyrite, and chalcopyrite. The neutralization potential of the waste rocks is mainly provided by silicates and by calcite that is present in traces in the olivine-pyroxenite from mine 3. Only one waste rock type generates nickel in its drainage water: the peridotite from the Kikialik mine (with an average of 0,280 mg/kg waste rock/year, and with corresponding concentrations below the Directive 019). This contamination could be produced by the dissolution of an alteration crust present on the surfaces of this rock type (not present in significant quantity for the other rock types) and by the oxidation of nickel sulphides (pentlandite) and of pyrrhotite that can contain nickel as impurity. Nickel is not leached from the other waste rock types on a short term, even if the peridotite from mine 3 and the olivinepyroxenite from mines 2 and 3 have sulphur and nickel contents in the initial solid equivalent or higher than those of the peridotite from the Kikialik mine. The absence of nickel in the drainage water of these rock types can be due to its precipitation on hydroxide formed at pH above 8, or to its sorption on the surfaces of the waste rocks. Due to these two phenomena that could occur (but can eventually disappear), we cannot conclude on the long term CND generation potential of the waste rocks. However, probabilities that the gabbro from mine 2, the argillite from mine 3 and the volcanic generate CND are very low considering their low nickel content.
机译：该项目的目的是在正常（实验室）和寒冷条件下表征不同废石类型的地球化学行为，而不受沉积物的矿物学影响。我们旨在提高我们对最终水污染的产生或衰减所涉及的现象的认识，并评估温度对这些现象的影响。为此，选择了七个代表性of石样品，每个样品代表不同的地质状况。在常温下对样品（70公斤）进行动力学和耗氧色谱柱测试，以确定waste石的污染潜力。在风化室（67 g）中进行了其他较小规模的测试，以评估温度对其地球化学行为的影响。该测试比色谱柱测试更具侵略性，因此可以更好地观察地球化学变化。蚀变电池显示，硫化物的氧化速率和硅酸盐的溶解速率随温度降低而降低，并且可以通过阿伦尼乌斯定律正确预测。在-6°C下观察到7种岩石中有5种的硫酸盐浸出量低，这表明该温度下硫化物的氧化程度低。由于方解石反应性的增加（痕量），钙在较低温度（10°C和-6°C）下比正常温度下的浸出量更大。这种溶解度的增加将响应于大气中溶解的二氧化碳产生的酸度，该酸度在较低温度下较高。钙的浸出在低温下增加，这与与中和矿物质（尤其是Ca + Mg）有关的化学元素的比例以及与硫化物氧化有关的硫酸盐的产生所反映。冷冻/解冻循环产生更高的硫化物氧化速率和铁浸出。当比较研究中获得的不同浸出率时，我们注意到色谱柱与风化室之间存在放大效应，并且还存在温度效应。但是，不可能使用单一关系来推断所有化学元素从一种规模或温度到另一种规模或温度的浸出率。；因此，根据这项研究的结果，我们建议拉格伦矿山处理废物具有短期CND潜力的岩石和可能产生酸的废石，并优先将其作为地下堆石，或填充露天矿井的底部，以利于它们整合到永久冻土中并降低其反应性。没有产酸潜力且只有长期CND潜力的材料可以在地面上存储更长的时间，甚至可以用于修复（例如，用作露天矿或尾矿堆中的废石的覆盖材料）。因此，在矿山运营期间，可以减少现场污染的产生以及与水处理和修复有关的成本。 （通过UMI缩短摘要。）；柱试验表明，七种废石类型中有六种可能不会产生酸（PAG）。来自矿山3的橄榄石-辉石岩的产酸潜力尚不确定。在the石中，酸度可以通过硫化物氧化产生。 waste石中存在的主要硫化物是黄铁矿，方铁矿，黄铁矿和黄铜矿。 mine石的中和潜力主要是由硅酸盐和方解石提供的，方解石存在于矿山3的橄榄石-辉石矿中的痕迹中。只有一种rock石类型在其排水中产生镍：Kikialik矿山中的橄榄岩（每年平均为0,280 mg / kg废石，且相应的浓度低于019号指令）。这种污染物的产生可能是由于溶解在该岩石类型表面上的蚀变壳（对于其他岩石类型而言并不大量存在）以及硫化镍（五氧化锰）和可能含有镍作为元素的黄铁矿的氧化所造成的。不纯。即使矿山3中的橄榄石和矿山2和3中的橄榄石辉绿岩的硫和镍的初始固含量当量或高于Kikialik橄榄岩中的镍和镍，短期内镍也不会从其他废石中浸出。矿。这些岩石类型的排水中不存在镍，可能是由于其在pH值高于8的氢氧化物上沉淀或在废石表面的吸附所致。由于可能会发生（但最终会消失）这两种现象，因此我们无法就waste石的长期CND生成潜力得出结论。但是，考虑到镍含量低，来自矿山2的辉长岩，​​来自矿山3的辉绿岩和火山产生CND的可能性非常低。

著录项

  • 作者

    Ethier, Marie-Pier.;

  • 作者单位

    Ecole Polytechnique, Montreal (Canada).;

  • 授予单位 Ecole Polytechnique, Montreal (Canada).;
  • 学科 Engineering Mining.;Geochemistry.;Engineering Environmental.
  • 学位 M.Sc.A.
  • 年度 2011
  • 页码 238 p.
  • 总页数 238
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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