Archives of Metallurgy and Materials

Abstract

A better understanding of phosphorus distribution in slag is necessary to develop an effective way to treat dephosphorization slag formed during steelmaking. Here, previous studies on the enrichment, separation, and recovery of phosphorus from dephosphorization slag are reviewed, along with their influencing factors. The results suggest that a proper heat treatment can promote the selective enrichment and growth of P-rich phases. Further, adding P 2 O 5 and Fe t O facilitates phosphorus enrichment. Also, Ca 3 (PO 4 ) 2 is precipitated from slag containing 18 wt% P 2 O 5 . MnO and MgO in the slag barely affect the phosphorus recovery. In contrast, the addition of Al 2 O 3 and TiO 2 significantly affects phosphorus enrichment and magnetic separation. A phosphorus recovery rate of more than 70% is achieved with the addition of 10 wt% Al 2 O 3 or 10 wt% TiO 2 . New phases (Na 2 Ca 4 (PO 4 ) 2 SiO 4 , Na 3 PO 4 , and Ca 5 (PO 4 ) 3 F) tend to be formed on the addition of Na 2 O and CaF 2 , which promote phosphorus enrichment. However, the addition of Na 2 O and CaF 2 results in the incomplete separation of phosphorus and iron, as CaF 2 and Na 2 O improve slag metallization and the magnetism of iron-rich phases.