Utilization of Waste TSRU Tailings as a Low-cost Additive for Cement-based Construction Materials

尾矿溶剂回收装置(TSRU)产生的废液中含有一定浓度(~5%)的沥青质、马来烯烃等碳氢化合物和分离后的固体颗粒(粘土)(~80%)。这些尾矿通常被丢弃在垃圾填埋场，这会增加环境危害。由于很少或根本不使用这些低价值的TSRU尾矿材料，它们作为水泥材料添加剂的潜在应用仍在很大程度上有待开发。商业级胶凝材料和混凝土约占全球温室气体排放量的8%。在这个项目中，我们的目标是利用TSRU尾矿材料(即沥青质、马来烯质和一些粘土)来开发一种新型的用于水泥基材料的废渣添加剂。我们的初步结果已经证明，这类废物对水泥混合料的力学性能有增强作用。我们预计，利用TSRU尾矿作为胶凝材料的添加剂可以提高水泥基建筑材料的整体性能。TSRU尾矿的进一步加工(即脱水、研磨和/或溶剂提取)可能仍然需要，并将在我们的研究中进行探索。这可以为定制胶凝材料的机械性能(同时使用废旧材料)开辟新的机会，这可能会在不久的将来获得水泥/混凝土添加剂的市场份额。利用TSRU尾矿材料开发低成本外加剂将为油砂行业和水泥/混凝土行业创造合作机会。拟议的TSRU尾矿有价化项目将使艾伯塔省的下游产业多样化，并有助于缓解二氧化碳排放和气候变化。

Waste by-products from tailings solvent recovery unit (TSRU) contain some concentrations of hydrocarbons (~5%) such as asphaltenes and maltenes and solid particles (clay) upon separation of the water phase (~80%). These tailings are usually disposed of in landfills that contribute towards increased environmental hazards. With little to no use of these low-value TSRU tailings materials, their potential applications as additives in cementitious materials remain largely unexplored. Commercial grade cementitious materials and concretes are responsible for ~8% of global greenhouse gas emissions. In this project, we aim to exploit the TSRU tailings materials (i.e., asphaltenes, maltenes, and some clay) towards developing a new waste-based additive for cement-based materials. Our preliminary results have already demonstrated the enhancing effect of such wastes on the mechanical performance of cementitious mixtures. We anticipate that utilization of TSRU tailings as an additive in cementitious materials can enhance the overall performance of cement-based construction materials. Further processing of the TSRU tailings (i.e. dewatering, grinding, and/or solvent extraction) may still be required and will be explored in our research. This can open up new opportunities to tailor the mechanical properties of cementitious materials (while employing waste materials), which may result in gaining cement/concrete additive market share in near future. The development of low-cost additives from TSRU tailings materials will establish collaboration opportunities between the oil sands industry and the cement/concrete industries. The proposed project on the valorization of TSRU tailings will diversify Alberta's downstream industry and help mitigate CO2 emissions and climate change.