AMD is the acidic discharge generated by the oxidation of sulfide minerals from active or disused mine workings and contains high concentrations of toxic metals and sulfuric acid. Host rocks and concrete-based infrastructures in permanent contact with AMD are highly vulnerable to the geochemical processes caused by acidity (e.g. concrete corrosion). Experiments using columns filled with calcareous sandstone and hydrated Portland cement were performed to quantify these geochemical processes. AMD mono-ionic and poly-ionic solutions containing sulfate, Fe(II), Al, Ca, Mg and different divalent cations (Cd, Zn, Cu and Ni) and As(V) at pH 2 were injected in the columns.

The temporal variation of the chemical composition of the output solutions was monitored. The retrieved solid samples were analyzed by X-Ray Diffraction (XRD), thin section petrography and Scanning Electron Microscopy (SEM). A quantitative interpretation of the reactions was carried out by means of 2D reactive transport modeling.

Results indicated that the main reactions were the dissolution of portlandite (hydrated Portland cement) and calcite (rock). These two reactions, together with the pH variation, played a pivotal role (1) in the precipitation of gypsum, aragonite, brucite and Fe- and Al- poorly crystalline phases (e.g., basaluminite, schwertmannite and ferrihydrite) and (2) in the precipitation of Cd, Ni and Zn hydroxides and Zn carbonates and adsorption or co-precipitation of Cu and As on schwertmannite and ferrihydrite.

AMD是酸性氧化物，是由活跃的或废弃的矿山中的硫化物矿物氧化而成的，并含有高浓度的有毒金属和硫酸。与AMD永久接触的基岩和混凝土基础设施极易受到酸度（例如混凝土腐蚀）引起的地球化学过程的影响。使用填充有钙质砂岩和水合硅酸盐水泥的柱子进行了实验，以量化这些地球化学过程。将含有硫酸盐，Fe（II），Al，Ca，Mg以及不同二价阳离子（Cd，Zn，Cu和Ni）和As（V）的pH为2的AMD单离子和聚离子溶液注入色谱柱中。

监测输出溶液的化学组成的时间变化。回收的固体样品通过X射线衍射（XRD），薄层岩石学和扫描电子显微镜（SEM）进行分析。通过2D反应性运输模型对反应进行定量解释。

结果表明，主要反应是硅酸盐（水合硅酸盐水泥）和方解石（岩石）的溶解。这两个反应以及pH的变化在（1）石膏，文石，水镁石以及Fe-和Al-弱结晶相（例如玄武岩，schwertmannite和铁水铁矿）的沉淀中起关键作用（2）。 Cd，Ni和Zn氢氧化物和碳酸锌的沉淀，以及Schwertmannite和铁水铁矿上Cu和As的吸附或共沉淀。