Textile Dyeing Sludge Incineration Ash as Iron-Correction Material for Production of Portland Cement Clinker

This study aimed to use textile dyeing sludge incineration ash (TDSIA) as an iron-correction material to produce portland cement clinkers. The influences of different TDSIA contents and calcination temperatures on the properties of cement clinker were investigated. The free calcium oxide (f-CaO) content, microstructure, and leaching toxicity of clinkers, and compressive strength, hydration heat, and microstructure of the cement pastes were investigate. The results showed that the incorporation of TDSIA can improve the burnability of cement raw meal and reduce the f-CaO content of clinker, and will not change the mineral phase of clinker, which is still C3S, C2S, C3A, and C4AF, and the minerals were well-formed. The dosage of TDSIA can promote the early hydration of cement, the nucleation and crystal growth of hydration products, improve the early compressive strength, and reduce the late compressive strength. The best preparation process was found to be as follows: TDSIA=4%, calcination temperature=1,400°C, and holding time=30 min. At this time, the 3- and 28-day compressive strengths of cement were 31.8 and 76.4 MPa, and the strength grade was 62.5. Finally, the heavy metal leaching concentrations of clinkers produced in this study satisfied the threshold standards specified in the current Chinese regulations.