Boron-Iron Separation and Boron Enrichment from Boron-Bearing Iron Concentrate at Low-Temperature Enhanced by Supergravity

Abstract

Boron-bearing iron concentrate, as the tailings of boron concentrate otained from ludwigite, still contains more than 5 wt.% of B₂O₃, which can hard to be utilized. In this study, low-temperature separation compared with high-temperature melting separation of boron and iron from boron-bearing iron concentrate, and the migration, transformation, separation and enrichment behaviors of boron in both processes were studied. High-temperature melting separation of iron and slag could be accomplished at 1823 K for 60 min, where the boron mainly distributed in a form of glass phase in the slag with a B₂O₃ content of 22.69 wt.%, while 0.35 wt.% of [B] was melted into the liquid iron. In contrast, iron and slag were efficiently separated at a low temperature of 1573 K for 10 min enhanced by supergravity, almost all of boron was enriched into suanite phase in the slag with a significantly higher B₂O₃ content of 35.61 wt.% and a high recovery ratio of 99.37%, and the content of B was decreased to 0.15 wt.% in the iron. Compared with high-temperature melting separation, low-temperature separation greatly improved the enrichment of boron in slag and avoided the melting of boron into iron.