**5. Conclusions**

The precipitation behavior of spinel crystals in the CaO-SiO2-MgO-Al2O3-Cr2O3-FeO system was studied by means of SEM-EDS, XRD, and IPP in the laboratory. Based on this study, the following conclusions were made:


**Author Contributions:** Y.Y. and Q.Z. helped to carry out the experimental work; Q.M. drafted the manuscript and conducted the experiments; J.L. analyzed the experimental data and modified and polished the draft.

**Funding:** The research was supported by the National Natural Science Foundation of China (No. 51404173), the Hubei Provincial Natural Science Foundation (No. 2016CFB579), the China Postdoctoral Science Foundation (No. 2014M562073), and the State Key Laboratory of Refractories and Metallurgy.

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

### **References**


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