Towards integrating micro- and macro- scale processes and tools to improve dewatering and rheology assessments in soft and ultra-soft tailings

整合微观和宏观流程和工具，以改进软尾矿和超软尾矿的脱水和流变评估

• 批准号: 518164-2017
• 负责人: Trifkovic, Milana
• 金额: $ 2.23万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=667140
• 关键词: Towards; integrating; micro; macro; scale

The tailings water from oil sands extraction contains suspended particles of ultra-fine clays and residual bitumen. These stable suspensions take a long time to settle to the bottom of the ponds (> 10 years). Hence, reducing the volume of tailings in a shorter duration is a major challenge. In addition, the reclaimed land still has a poor mechanical strength for it to be returned to nature. Adding thickeners such as polyacrylamide (PAM) to these processes is considered an attractive method for improved soil consolidation. Even though the polymers are cheap, the overall treatment cost remains high. In addition, the issues of fate and transport of such polymers, as well as their ecotoxicity, are still not resolved. It is also not yet clear if the final strength of consolidated soil will meet the Alberta government's minimum requirements of geotechnical strength.****The goal of this project is to investigate the influence of the micro-scale structure of the flocculated tailings systems on the macro-scale dewatering and rheological properties of soft and ultra-soft fines dominated deposits. Flocs are a clumped group of clay particles and, if added, a polymer that forms the basic structure of soft tailings. Observing, understanding and quantifying the flocculation mechanisms during critical processes such as dewatering and deposition (e.g. under shear) can potentially represent a fundamental big step forward in the prediction of consolidation and deposition operation, hence in the effective management of oil sands tailings. If successful, this allows direct correlation between the choice of a specific treatment of fluid tailings (e.g. addition of the flocculant, mixing and deposition rate) and long-term dewatering and strength performance (e.g. deep deposit consolidation rate, sand segregation, fines capture), with potential for future extrapolation to long-term reclamation objective.****** ****

油砂开采尾水含有悬浮的超细粘土颗粒和残余沥青。这些稳定的悬浮液需要很长时间才能沉降到池塘底部（> 10年）。因此，在较短时间内减少尾矿量是一项重大挑战。此外，填海土地的机械强度仍然很差，无法回归自然。在这些过程中加入增稠剂如聚丙烯酰胺（PAM）被认为是一种有吸引力的方法，用于改善土壤固结。尽管聚合物便宜，但总的处理成本仍然很高。此外，这类聚合物的归宿和运输以及它们的生态毒性问题仍未得到解决。目前还不清楚固结土壤的最终强度是否符合阿尔伯塔政府对岩土强度的最低要求。*该项目的目标是研究絮凝尾矿系统的微观结构对以软和超软细粒为主的沉积物的宏观脱水和流变性质的影响。絮凝体是一组粘土颗粒的聚集体，如果加入，则是形成软尾矿基本结构的聚合物。观察、理解和量化脱水和沉积（例如剪切）等关键过程中的絮凝机制可能代表着固结和沉积操作预测的重要一步，因此也是油砂尾矿有效管理的重要一步。 如果成功的话，这将使流体尾矿的特定处理（例如添加絮凝剂、混合和沉积速率）的选择与长期脱水和强度性能（例如深层存款固结速率、砂分离、细粒捕获）之间直接相关，并有可能在未来外推到长期复垦目标。****