PFI-TT: Development of Scalable Lightweight Aggregate Manufacturing from Waste Coal Combustion Ash

这个创新技术转化伙伴关系项目的更广泛的影响/商业潜力是重新利用燃烧煤炭的未使用或废弃产品，称为煤炭燃烧灰（CCA）；这项技术将把CCA转化为一种叫做轻骨料（LWA）的混凝土。在美国，每年产生近1.2亿吨CCA，其中只有40%被再利用；剩余的CCA几乎没有回收途径，影响环境和人类健康。同时，对LWA需求的增加影响了混凝土和岩土工程行业的成本。将CCA转换为增值LWA不仅解决了CCA风险，而且通过开发一种以更低成本提高物理性能的产品，同时解决了这两个因素。CCA在美国大量可用，LWA可以在其市场附近生产。该项目还将鼓励学生，包括未被充分代表的少数民族和女性，学习工程。拟议的项目将制定、开发和验证一种创新的可扩展的基于热力学的制造技术，该技术可用于从未使用/废弃的CCA中生产可持续的LWA。利用热力学原理和相平衡，将CCA的烧结过程调整为部分熔化CCA的氧化物化合物，随后在烧结过程中燃烧排放的气体，以产生多孔CCA基LWA材料。开发的技术将能够识别优化的原材料混合，适当的助熔剂选择，以及尽管CCA的异质性，化学成分和多样性，允许将大量未使用和废弃的CCA转化为增值的基于CCA的LWA。该项目将通过(1)观察不同类型和剂量的CCA和助熔剂之间的化学相互作用来产生LWA，(2)确定相平衡热力学是烧结过程中温度随CCA剂量和成分变化的函数，以及(3)准备一个可靠的技术指南，并通过实验室中试工作进行校准。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact/commercial potential of this Partnerships for Innovation-Technology Translation (PFI-TT) project is to reuse the unused or waste products of burning coal, known as coal combustion ash (CCA); this technology will convert CCA into a type of concrete called lightweight aggregate (LWA). Every year in the United States, nearly 120 million tons of CCA are generated, of which only 40% is reused; few recycling avenues exist for the remaining CCA, affecting the environment and human health. Simultaneously, increased demand for LWA has impacted costs in the concrete and geotechnical industries. Converting CCA to value-added LWA addresses not only the CCA risk, but both these factors at once by developing a product with improved physical performance at lower costs. CCA is abundantly available in the United States, and LWA can be produced near its markets. This project will also encourage students, including underrepresented minorities and females, in engineering. The proposed project will formulate, develop and validate an innovative scalable thermodynamic-based manufacturing technology that can be used to produce sustainable LWA from unused/waste CCA. Using thermodynamic principles and phase equilibria, sintering process of CCA will be tuned to partially melt the oxide compounds of CCA and subsequently combust emitted gas during sintering to create porous CCA-based LWA materials. The developed technology will enable identification of optimized raw material blending, appropriate fluxing agent selections, and the sintering process despite CCA heterogeneity, chemical composition and diversity, allowing conversion of significant amount of unused and waste CCA into value-added CCA-based LWA. This project will develop the technology by (1) looking at the chemical interactions between various types and dosages of CCA and fluxing agents to produce LWA, (2) identifying the thermodynamics of phase equilibria as a function of temperature during sintering as dosage and compositions of CCA vary and (3) preparing a robust technology guideline calibrated with experimental laboratory pilot-scale works.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.