Enrichment of Phosphorus Oxide in Steelmaking Slag by Utilizing Capillary Action

Abstract

The recoverability of phosphorus oxide from steelmaking slag was investigated using a mechanical approach involving capillary action. It was found that P 2 O 5 was concentrated in the 2CaOÁSiO 2 phase. To separate the P 2 O 5 -enriched solid 2CaOÁSiO 2 phase and FeO-rich liquid phase in steelmaking slag, capillary action was used to facilitate penetration into absorbers such as sintered CaO, Fe 2 O 3 , and CaCO 3 tablet. Once the liquid phase had penetrated the absorber, it was found that the solid 2CaOÁSiO 2 phase and FeO-rich phase could be effectively separated. When CaCO 3 was used as an absorber, 91 % of phosphorus oxide in the steelmaking slag was recovered in solid 2CaOÁSiO 2 phase. The recovered absorber, which includes a FeO-rich liquid phase, may be used as Fe source, and the 2CaOÁSiO 2 phase, which includes P 2 O 5 , may be used as P source.

Alkali Activation of Ladle Slag from Steel-Making Process

“…Various researchers have proposed an alternative use of LS as fillers in self-compacting concrete and in masonry mortars [3][4][5], and also in landfill covering as filtering beds and in stabilizing soft clayey soils [2,6]. The chemical composition of LS varies according to the steel-making factories' processes, conditions and additives; however, the composition includes CaO, SiO2, Al2O3 and MgO, which makes this slag a potential binder in alkali activation [7].…”

Extraction of Phosphorus and Recovery of Phosphate from Steelmaking Slag by Selective Leaching

“…Separation of C 2 S-C 3 P is achieved by already developed methods exploiting its differences from other phases, in terms of magnetic properties, 5) differences in density, 6,7) and capillary separation. 8) This study is focused on differences in the water solubility of the phases in order to selectively leach P out of C 2 S-C 3 P from the steelmaking slag . Previously, serial studies on the leaching of slags rich in P 2 O 5 have been conducted, [11][12][13] which have assumed that the P 2 O 5 content in dephosphorization slag arises due to iron ore depletion; this process will be increasingly used in the future.…”