Effect of basicity on dephosphorization of hot metal with a low basicity slag at 1653 K

ABSTRACT

This research aims to investigate the influence of the slag basicity from 1.40 to 1.83 on dephosphorization of the hot metal with a CaO–FeO–SiO₂–MgO–Al₂O₃ molten slag at the low temperature of 1653 K. The results indicated that the dephosphorization ratio was increased with the increase of basicity. Even at the low basicities of 1.73 and 1.83, the dephosphorization ratios can be as high as 77.3 and 80.7%, respectively. With the increase of basicity, the contents of P₂O₅ and total iron in the slag were increased, whereas the content of MnO was decreased. The distribution ratio of phosphorus $\left(L_{\mathrm{P}}\right)$ was expressed as $\log L_{\mathrm{P}}=19.4\mathrm{\Lambda }-{\displaystyle \frac{6381}{T}+5.244+\log f_{\mathrm{P}}+\frac{5}{4}\log P_{\left({\mathrm{O}}_2\right)}}$. The $L_{\mathrm{P}}$ values calculated by the present method are well consistent with the measurement values. Besides, the dark grey phase B and the light grey phase D could be considered as the phosphorus-rich phases containing C₂S solid particles.

KEYWORDS:

• Dephosphorization
• distribution ratio of phosphorus
• hot metal
• solid solution
• phosphorus enrichment
• molten slag
• low temperature
• low basicity

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Natural Science Foundation of China [Grant Number U1960202].