Aluminum dust recycled as aerating agent for the production of autoclaved aerated concrete

Aluminum dust is a by-product of aluminum dross recycling industry. There is some metallic aluminum in aluminum dust from composition analysis. In this paper, aluminum dust is used as aerating agent to replace metallic aluminum powder for the production of autoclaved aerated concrete (AAC). The results showed that aluminum dust can successfully replace aluminum powder in AAC production and the gas generation capacity of aluminum dust is around one sixteenth of that of aluminum powder. However, the incorporation of aluminum dust into AAC paste can make a fast yield stress gain to the AAC paste. Therefore, comparing with aluminum powder AAC, aluminum dust AAC has smaller pore size, lower porosity, higher density and higher compressive strength. Furthermore, the porosity of aluminum dust AAC cannot be further increased by increasing aluminum dust dosage because higher aluminum dust dosage leads to a faster yield stress gain. In general, this paper revealed a viable way to recycle aluminum dust in AAC production rather than direct landfill, but further study to optimize the property of aluminum dust AAC needs to be done in future.