ABSTRACT
With the extensive use of low-grade Cr-containing ore, the dephosphorisation issue of hot metal containing moderate amounts (0.2%-1%) of chromium is gaining more and more attention. To achieve dephosphorisation and chromium retention, a series of experiments on the dephosphorisation of hot metal containing moderate amounts of chromium were carried out at 1723 K. In the experiments, the crystallisation performance of the slag with various CaO/Fe2O3 ratio and Cr2O3 content, as well as the transfer of phosphorus and chromium between slag and hot metal at 1723 K were investigated. The results show that the dephosphorisation process goes through four stages: melting and precipitation, dissolution of refractory, continual oxidation, and phase transition. With the increase of CaO/Fe2O3 ratio, the chromium loss decreases while the dephosphorisation ratio first increases and then decreases. The addition of Cr2O3 promotes the precipitation of Fe(Cr,Al)2O4, which inhibits the dephosphorisation and chromium loss.
Acknowledgements
This work was supported by the National Natural Science Foundation of China and Steel Joint Research Fund of China BaoWu Steel Group Co., LTD (No. U1960110, 1660116, and U1560109).
Disclosure statement
No potential conflict of interest was reported by the author(s).