Canadian Geotechnical Journal, Ahead of Print.
Upstream tailings dams are high-risk structures that have experienced several failures worldwide, particularly with iron ore tailings (IOT). In this study, new disposal methods/techniques, such as cement-stabilized dry stacking, are discussed that provide enhanced mechanical behavior while reducing failure risks. Alkali-activated materials are used as cementing agents due to their mechanical and environmental advantages compared to ordinary Portland cement. This study evaluates the mechanical and microstructural behavior of IOT stabilized with an alkali-activated cement (AAC) composed of two by-products from the IOT beneficiation process, metakaolin and sodium silicate, tested under plane strain conditions. Simple shear tests and microstructural analysis were performed. Mixtures of IOT were produced with 0%, 1%, 3%, and 5% AAC to examine the influence of such variables on strength and deformability parameters under undrained conditions. The mixtures with 3% and 5% AAC showed the greatest impact on the strength; however, the addition of 1% AAC was able to reduce positive pore-pressure generation. Cementitious bounds were evidenced by forming a sodium aluminosilicate hydrate gel. The studied AAC was effective in stabilizing IOT, even at small contents.

中文翻译：

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使用用于干堆的替代碱活化水泥稳定铁矿石尾矿：机械和微观结构见解

加拿大岩土工程杂志，印刷前。
上游尾矿坝是高风险结构，在世界范围内经历过多次失败，特别是铁矿石尾矿坝（IOT）。在这项研究中，讨论了新的处置方法/技术，例如水泥稳定干堆，可以增强机械性能，同时降低失效风险。与普通波特兰水泥相比，碱激活材料由于其机械和环境优势而被用作胶结剂。本研究评估了用碱活化水泥（AAC）稳定的物联网的机械和微观结构行为，该水泥由物联网选矿过程中的两种副产品偏高岭土和硅酸钠组成，并在平面应变条件下进行了测试。进行了简单的剪切测试和微观结构分析。使用 0%、1%、3% 和 5% AAC 生产 IOT 混合物，以检查这些变量在不排水条件下对强度和变形参数的影响。 3％和5％AAC的混合物对强度的影响最大；然而，添加 1% AAC 能够减少正孔隙压力的产生。通过形成硅铝酸钠水合物凝胶来证明水泥质边界。所研究的 AAC 可以有效稳定 IOT，即使内容很小。