The fundamental understanding of hydrogeochemical processes leading to toxic drainage in mining environments is of utmost importance to predict the impact of mining activities in waste facilities and to design effective measures for the mitigation of environmental risk. This study investigates the weathering behavior of different types of mine waste rocks, with considerably different mineralogical and textural properties, by performing long-term (>3 years) pilot-scale lysimeter experiments combined with multiphase and multicomponent reactive transport modeling. The experiments were carried out in a series of five lysimeter setups, packed with unsaturated waste rocks collected from the Kevitsa and Hitura mine sites in Finland, under the influence of outdoor atmospheric conditions. We focus on the temporal dynamics of the waste rock effluents’ chemistry showing remarkably different compositions in different experiments. The low-sulfide containing Kevitsa pyroxene and Hitura serpentinite waste rocks lead to alkaline drainage, characterized by higher pH (up to 9.5) and lower dissolved constituents (e.g., up to 420 mg/L SO₄, 89 μg/L Ni). In contrast, the effluents from the Hitura mica schist waste rocks, which have relatively higher sulfide abundance, show characteristics of acidic drainage with lower pH (~4.3) and orders of magnitude higher aqueous concentrations (e.g., up to 3100 mg/L SO₄, 130 mg/L Ni). The results also show that the presence of a higher fraction of finer particles leads to a faster dissolution rate and thus relatively higher drainage concentrations. The experimental results were quantitatively interpreted with multiphase and multicomponent reactive transport modeling, which allowed capturing the complex dynamic trends and the concentration levels observed in the effluents of the different pilot-scale lysimeters.

对于预测采矿环境中采矿活动的影响并设计减轻环境风险的有效措施，最重要的是对导致采矿环境中有毒排放的水文地球化学过程的基本理解。本研究通过进行长期（> 3年）中试规模的溶渗仪实验，并结合多相和多组分反应输运模型，研究了具有不同矿物学和质地特性的不同类型矿山废石的风化行为。在室外大气条件的影响下，以五台测渗仪进行了一系列实验，这些测井仪装有从芬兰的Kevitsa和Hitura矿场收集的不饱和废石。我们专注于废石废水化学成分的时间动态，在不同的实验中显示出明显不同的组成。含Kevitsa辉石和Hitura蛇纹石废石的低硫化物导致碱性排水，其特征在于较高的pH（高达9.5）和较低的溶解成分（例如，高达420 mg / L SO）₄，89微克/升的Ni）。相比之下，来自日立云母片岩废石的废水具有较高的硫化物丰度，具有较低的pH值（〜4.3）和较高的水浓度（例如，最高3100 mg / L SO ₄）呈酸性排水的特征。，130 mg / L Ni）。结果还表明，较高比例的较细颗粒的存在导致较快的溶解速率，因此相对较高的排泄浓度。用多相和多组分反应性运输模型定量解释了实验结果，该模型可以捕获复杂的动态趋势和在不同的中试规模的渗滤仪的废水中观察到的浓度水平。