Abstract
Iron ore tailings (IOTs) and coal gasification slag (CGS) were used to prepare novel ceramsites via high-temperature sintering. The IOTs were activated by NaOH to form a geopolymer that was sintered at 650 °C, 850 °C, and 1050 °C to obtain ceramsites. The formation of the geopolymer was confirmed by the characteristic peaks of Si–O–T (T = Si, Al) in the Fourier transform infrared spectra. X-ray diffractograms showed that Fe 3+ participated in the geopolymerization reaction, whereas Fe 2+ did not; hence the effect of the Fe 2+ /Fe 3+ ratio was investigated. This ratio increased with increasing sintering temperature, thereby facilitating nucleation within the sample. The mullite–pyroxene network that formed upon sintering at 1050 °C improved the strength of the prepared ceramsite and its structure became more compact. Specifically, the cylinder compressive strength increased from 10.5 to 35.5 MPa after sintering at 1050 °C. Overall, this method of preparing high-strength ceramsites from IOTs and CGS can be used for the preparation of high-strength lightweight concrete. • Compressive strength of ceramsite tripled after alkali-activated pretreatment. • Fe 3+ ions participated in the geopolymerisation reaction; Fe 2+ ions had no effect. • Fe 2+ /Fe 3+ ratio had a notable effect on the internal crystallization of ceramsite. • Mullite pyroxene network structure enhanced the strength of ceramsites.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
