The utilization of ammonia soda residue in building materials: A review

Ammonia soda residue (ASR) is the waste generated from the production of soda ash (Na2CO3) using the ammonia-soda process, with rarely reused and commonly stored in the storage facilities of soda plants, not only causes environmental contamination, land-occupying, and resourcewasting but also poses threats to the sustainable development of soda plants. Based on analyzed the generation and physicochemical properties of ASR, this paper provided a comprehensive review and summary of its applications in building materials, including cementitious materials, bricks, and road base materials. Additionally, the risks and challenges associated with the reuse of ASR in construction materials were also examined. The findings indicate that ASR has the advantages of strong alkalinity, high calcium content, small particle size, and large specific surface area, which make ASR has great potential for recycling as raw material in the field of building materials. However, due to the limitations of the ammonia-soda process, ASR contains a notable concentration of chloride ions. Integrating undechlorinated ASR into building material production may result in Cl dissolution, thereby compromising the durability of ASR-based building materials. At present, there is still a lack of effective and environmentally safe methods to remove Cl from ASR, which hinders the large-scale application of ASR. Overall, the utilization of ASR in building materials is still in its early stages, and further research is needed on durability and life-cycle assessments to enhance the safety and feasibility of ASR in construction applications. In addition, exploring the combination of ASR utilization with carbon sequestration methods and computer regression models presents a promising research direction that could accelerate the development and implementation of these materials, ultimately leading to more sustainable construction practices.