Geotechnical evaluation of uranium tailings for enhanced dewatering

加拿大的铀矿开采行业在环保方面走在了前列。尾矿（作为金属提取的副产品）传统上储存在大型密封设施中，并进行了几十年的彻底监测。为了减少空间要求和时间承诺，Cameco公司最近发起了一项开发工程尾矿流的倡议。这种新型尾矿将具有优越的岩土性能（偏析、沉降、固结和水力导电性），这也将有助于地球化学（扩散控制运动）的稳定性。作为Cameco公司工程尾矿计划的一部分，这项合作研究的主要目标是了解和改进下一代铀尾矿的脱水和离析行为。这是Cameco公司第一次对铀尾矿流进行如此详细的岩土工程评价。基于一个全面的研究计划，将开发一个创新的科学框架来研究选定的浆料与固液界面复杂的物理化学相互作用。这是传统岩土工程的一个范式转变，传统岩土工程通过考虑土壤的化学惰性来处理土壤行为的物理理解。拟议的研究将是Cameco公司关于其未来扩张计划的重大发展。由此产生的技术（物理化学模型、不分离尾矿、改进脱水和三元图）将对加拿大各种采矿作业的尾矿设计至关重要。不同物料尾矿改良方法的预期经济效益可分为以下几个方面：(1)提高了尾矿库的库容；（ii）由于金属流动性降低，环境责任降低；（三）增加工艺用水和化学试剂的回收；（四）提高了选矿过程各阶段的平衡用水量。同样，基础设施能力的发展、合格专业人员的招聘和跨学科的扩展对里贾纳大学来说是重要的好处。

The uranium mining industry in Canada is at the forefront of environmental compliance. The tailings (produced as a by-product of metal extraction) have been traditionally stored in large containment facilities and thoroughly monitored for several decades. To reduce both space requirements and time commitment, Cameco Inc. has recently launched an initiative to develop engineered tailings streams. This new category of tailings will have superior geotechnical properties (segregation, sedimentation, consolidation, and hydraulic conductivity) that will also contribute to geochemical (diffusion-controlled movement) stability. As part of Cameco Inc.'s engineered tailings initiative, the main objective of this collaborative research is to understand and improve the dewatering and segregation behavior of the next-generation uranium tailings. This is the first time that such a detailed geotechnical evaluation of the uranium tailings streams is undertaken at Cameco Inc. Based on a comprehensive research program, an innovative scientific framework will be developed to study the selected slurries in conjunction with complex physicochemical interactions at the solid-liquid interface. This is a paradigm shift from conventional geotechnical engineering that deals with the physical understanding of soil behavior by considering the soil as chemically inert. The proposed research will be a significant development for Cameco Inc. with respect to its future expansion plans. The resulting technology (physicochemical model, nonsegregating tailings, improved dewatering, and ternary diagram) will be pivotal for tailings design at various Canadian mining operations. The expected economic benefits of material-specific tailings amelioration methods can be classified as follows: (i) increased storage capacity of the tailings impoundments; (ii) lower environmental liabilities due to reduced metal mobility; (iii) increased reclamation of process water and chemical reagents; and (iv) improved balance water consumption at various stages in the ore beneficiation process. Likewise, the infrastructure capacity development, recruitment of qualified professionals, and cross-disciplinary extensions are important benefits for the University of Regina.