**5. Conclusions**

This paper examines industrial byproducts (ferronickel slags) to evaluate their suitability as concrete aggregates, with the ultimate goal of the production of environmentally friendly concrete from now on. The main conclusions of this study are given in the remarks below:


**Author Contributions:** Conceptualization, P.P.; methodology, P.P., A.R., P.P.G. and P.L.; software, P.P., A.R. and A.C.; investigation, P.P., A.R., P.P.G., A.C., S.L. and P.L.; resources, P.P., P.P.G., A.C. and P.L.; data curation, P.P., A.R., P.P.G., A.C. and P.L.; writing—original draft preparation, P.P. and P.P.G.; writing—review and editing, P.P., A.R., P.P.G. and N.K.; visualization, P.P. and P.K.; supervision, P.P. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
