EAGER: Sustainable Structural Binders from Iron Carbonation

EARLY概念探索性研究（EAGER）项目旨在评估一种新方法的可行性，该方法通过废弃物/副产品金属铁粉的碳酸化过程生产用于结构混凝土应用的粘合剂。具体目标包括测定铁粉在环境温度和压力下的碳酸化效率，需要引入复合形成剂和溶解助剂以增加反应产物的形成，以及对粘结剂的机械行为的初步了解。将使用先进的表征工具对反应产物进行表征，以辨别源材料和加工条件的影响，并将其与材料的机械性能联系起来。作为反应副产物的H2的产生需要仔细考虑，因为它影响孔结构。在这些系统中的反应动力学的初步迹象将通过实验技术和简单的模型，预计将是至关重要的进一步材料设计和工艺优化所需的机械性能的组合。 该项目描绘了一个新的过程，通过不依赖波特兰水泥水化或铝硅酸盐的碱性活化，开发可持续的混凝土粘结剂系统。使用废物/副产品材料（目前被填埋）作为主要来源材料，并使用温室气体作为反应的促成剂，这带来了资源保护和回收以及CO2封存的双重好处。确定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开发用于各种应用的高性能净碳负材料，包括室温加工的中等强度陶瓷类基质。 从教育的角度来看，这项研究将继续不断努力，指导研究生和本科生，并从事高中学生的研究。

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.