Utilization of Textile-Dyeing Sludge Incineration Ash in Autoclaved Aerated Concrete

Abstract

Utilizing hazardous solid waste to produce autoclaved aerated concrete (AAC) has been a prominent area of research in the building materials industry. This paper proposes the preparation of AAC by substituting quartz sand with solid waste textile-dyeing sludge incineration ash, which met A5.0 (compressive strength ≥5 MPa) and B07 (Bulk density ≤750 kg/m3) grade requirements. The hydration products in AAC by using textile-dyeing sludge incineration ash (TDSIA) were evaluated by X-ray diffraction, thermogravimetry, and field emission scanning electron microscopy. The results indicated that CaSO4,Fe3O4, and others in TDSIA were generating hydrogarnet, calcium aluminate hydrate, ettringite, and calcium iron aluminum silicate. Grinding was found to promote the autoclaved hydration of CaSO4 and Fe3O4 in TDSIA. The AAC process effectively immobilized heavy metals from TDSIA and led to a lower concentration of heavy metals in the leachate. These findings offer a promising and environment-friendly method for the resource utilization of TDSIA.