Utilization of local raw materials and mine waste to manufacture cement in Northwest Territories, Canada

Abstract

Currently, all the cement consumed in Northwest Territories (NWT), Canada, is imported from other provinces (e.g., Alberta) by long-distance (∼1,800 km) truck freight. Transporting cement over long distances not only raises its cost, but also results in a higher carbon footprint. Locally producing cement is a potential low-carbon and economic solution for the local industry. However, it is unknown if the local raw materials are suitable for cement manufacturing; and there is a lack of a critical raw material—Iron ore—for cement manufacturing. Instead of iron ore, there are iron-rich tailings from a local rare earth element (REE) mine. Towards low-carbon and circular economy, this study explored the use of local raw materials (i.e., limestone, clay, and gypsum) and mine waste (REE tailings) to manufacture cement in the NWT and successfully produced the first bag of cement in the history of the NWT. The results showed that concrete samples made with NWT cement achieved comparable strength of commercial OPC-based concrete. An emission estimation suggested that locally producing cement in the NWT has the potential to reduce 3.0%–61.7% of CO2 emissions when compared with importing cement from other provinces.