EAGER: Sustainable Structural Binders from Iron Carbonation

这个初步构想的探索性研究奖助金(AGIRE)项目旨在评估一种新方法的可行性，该方法通过对废/副产品金属铁粉进行碳化处理来生产用于结构混凝土的粘结剂。具体目标包括测定铁粉在常温常压下的碳化效率，需要引入复杂的成形剂和溶解助剂以增加反应产物的形成，以及对粘结剂的力学行为的初步了解。反应产物(S)将使用先进的表征工具进行表征，以辨别来源材料和工艺条件的影响，并将其与材料的机械性能联系起来。作为反应副产物的氢气的产生需要仔细考虑，因为它会影响孔结构。通过实验技术和简单模型的结合，将获得这些体系中反应动力学的初步指示，这将对进一步的材料设计和工艺优化以获得所需的机械性能至关重要。该项目描绘了一条新的道路，通过不依赖波特兰水泥水化或铝硅酸盐的碱性活化来开发用于混凝土的可持续粘结剂系统。使用废物/副产品材料(目前是填埋的)作为主要来源材料，使用温室气体作为反应的促进剂，可以带来资源节约和回收以及二氧化碳封存的双重好处。建立碳酸铁粘结剂形成的可行性和材料性能的充分性可以加速高性能、净碳负材料的发展，用于各种应用，包括室温处理的中等强度陶瓷基材。从教育的角度来看，这项研究将继续努力指导研究生和本科生，并吸引高中生参与研究。

This EArly-concept Grant for Exploratory Research (EAGER) project is to evaluate the feasibility of a novel approach towards producing binders for structural concrete applications through the carbonation process of waste/by-product metallic iron powder. The specific objectives include the determination of carbonation efficiency of iron powder under ambient temperature and pressure, the need to introduce complex formation agents and dissolution aids to increase the reaction product formation, and a preliminary understanding of the mechanical behavior of the binder. The reaction product(s) will be characterized using advanced characterization tools to discern the effects of source materials and processing conditions, and to link those to the mechanical properties of the material. The production of H2 as a by-product of the reaction requires careful consideration since it impacts the pore structure. Preliminary indications of the reaction kinetics in these systems will be arrived at through a combination of experimental techniques and simple models, which are expected to be vital towards further material design and process optimization for desired mechanical properties. This project charts a novel course towards developing sustainable binder systems for concrete by not relying on portland cement hydration or alkaline activation of aluminosilicates. The use of a waste/by-product material (which is currently landfilled) as the major source material, and a greenhouse gas as the enabler of the reaction forwards the twin benefits of resource conservation and recycling, and CO2 sequestration. Establishing the feasibility of iron carbonate binder formation and adequacy of the material properties could accelerate the development of high-performance, net carbon-negative materials for a variety of applications including room-temperature processed moderate strength ceramic-like matrices. From an educational perspective, this research will continue the on-going efforts to mentor graduate and undergraduate students and to engage high-school students in research.