## 4 Conclusions  
In this work, the effect of temperature and heating rate on the post-heated properties of CaO-FeO\({}_{\mathrm{x}}\)-Al\({}_{2}\)O\({}_{3}\)-SiO\({}_{2}\)-rich AAMs was investigated. The mix design of the AAMs employed a high content of a low-value residue (85.9 wt.%). This was driven by the aim to reduce the production cost and environmental impact of the produced materials, thus providing an up-cycling solution for the large volumes of CaO-FeO\({}_{\mathrm{x}}\)-Al\({}_{2}\)O\({}_{3}\)-SiO\({}_{2}\)-rich slags generated in thermochemical conversion processes.  
The results demonstrated the superior thermal performance of AAMs produced from these residues relative to mainstream construction materials and acknowledged the vital role of both of temperature and heating rate. Lower heating rates had a beneficial effect on AAMs' mechanical performance. The maximum strength was observed when specimens were exposed to 1100 \({}^{\circ}\)C at 1 \({}^{\circ}\)C/min (184 \(\pm\) 13 MPa), more than doubling the compressive strength of green mortars (85 \(\pm\) 3 MPa). Increasing the heating rate from 1 to 10 \({}^{\circ}\)C/min was found to promote deterioration processes that resulted in extensive crack development and even the deformation of samples at 1100 \({}^{\circ}\)C. Along with the formation of less homogeneous microstructures, these deleterious effects were found to result in more fragile structures after thermal exposure, which limits sintering to 900 \({}^{\circ}\)C if high heating rates are involved.  
Crystallographic analyses revealed the crystallization of thermally stable phases, indicating that the refractory and high-temperature resistant features of the developed CaO-FeO\({}_{\mathrm{x}}\)-Al\({}_{2}\)O\({}_{3}\)-SiO\({}_{2}\)-rich AAMs could be potentially further enhanced by fine-tuning the mix design.  
Comparing to benchmark materials based on OPC, no signs of spalling were visible, and the developed materials could withstand temperatures up to 900 \({}^{\circ}\)C with heating rates up to 10 \({}^{\circ}\)C/min while maintaining their structural integrity and considerable mechanical strength (\(>\)40 MPa).  
**Author Contributions:** Conceptualization, G.A.; methodology, G.A.; validation, G.A.; formal analysis, G.A., M.S., J.V.D.S., H.R., E.B. and Y.P.; investigation, G.A.; resources, F.F., M.M., E.B. and Y.P.; data curation, G.A; writing--original draft preparation, G.A.; writing--review and editing, F.F., M.M., M.S., J.V.D.S., H.R., E.B. and Y.P.; visualization, G.A.; supervision, F.F., M.M. and Y.P.; project administration, F.F., M.M. and Y.P.; funding acquisition, F.F., M.M., E.B. and Y.P. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the European Union's EU Framework Programme for Research and Innovation Horizon 2020 [Grant Agreement No 721185]. [PERSON]'s work was also supported by the Foundation for Science and Technology (FCT)-Aveiro Research Centre for Risks and Sustainability in Construction (RISCO), Universidade de Aveiro, Portugal [FCT/UIDB/ECI/04450/2020]. This publication reflects only the author's view, exempting the Community from any liability. Project website: [[https://new-mine.eu/](https://new-mine.eu/)]([https://new-mine.eu/](https://new-mine.eu/)) (accessed on 6 January 2022).  
Not applicable.  
**Acknowledgments:** The authors wish to thanks to [PERSON] for her assistance in performing the high temperature tests.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.