Distribution of P2O5 between Solid Solution of 2CaO·SiO2–3CaO·P2O5 and Liquid Phase

Pahlevani, Farshid; Kitamura, Shin Ya; Shibata, Hiroyuki; Maruoka, Nobuhiro

doi:10.2355/isijinternational.50.822

Cited by 103 publications

(78 citation statements)

References 8 publications

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“…It was also interesting to note that the central part of the polygonal grey crystal (phase A) (Fig. 7(b)) mainly consisted of CaO and SiO 2 , which can be identified as 2CaO·SiO 2 , i.e., the main part of nC 2 S-C 3 P solid solution, 20,21) as shown in Table 2. However, with the addition of CaF 2 , it can be clearly observed that the primary crystal was typical bar-type structure.…”

Section: Identification Of Crystalline Phasesmentioning

confidence: 99%

Viscous Flow and Crystallization Behaviors of P-bearing Steelmaking Slags with Varying Fluorine Content

et al. 2016

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The role of fluorine in the CaO-SiO 2 -MgO-Al 2 O 3 -Fe t O steelmaking slags was investigated through analyzing the viscous flow and crystallization behaviors of the slags. It was found that the viscosity decreased with increasing CaF 2 content, which resulted from the decrease of the degree of polymerization (DOP) of the structures, as proved by O 1s X-ray photoelectron spectroscopy (XPS) and magic angular spinning nuclear magnetic resonance (MAS-NMR) analysis. The continuous cooling transformation (CCT) diagrams of the primary crystals were also constructed. The results showed that CaF 2 addition promoted the transformation of the primary crystal from spinel (MgFe 2 O 4 ) to flourapatite (Ca 5 (PO 4 ) 3 F), which was beneficial to the further enrichment of phosphorus. According to 19 F MAS-NMR results, F − ions mainly coordinate with Ca 2 + ions to form Ca-F bond. Furthermore, considering the greater stability of P-O-Ca than that of Si-OCa bonds, most of the F − ions behave as F-Ca-O-P band, which thus enhanced the formation of Ca 5 (PO 4 ) 3 F. Additionally, the non-isothermal crystallization kinetics was further analyzed and the activation energy for the primary crystal growth was derived.

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Section: Identification Of Crystalline Phasesmentioning

confidence: 99%

Viscous Flow and Crystallization Behaviors of P-bearing Steelmaking Slags with Varying Fluorine Content

et al. 2016

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“…A escória de desfosforação é normalmente composta de um sistema CaO-SiO2-FeO-P2O5, sendo de conhecimento que a formação da fase sólida silicato dicálcio (2CaO.SiO2) tem papel de grande importância por formar uma solução sólida com o principal produto da desfosforação, o 3CaO.P2O5. Estes formam uma solução sólida de 2CaO.SiO2-3CaO.P2O5 com a escória liquida [5]. A formação do 2CaO.SiO2-3CaO.P2O5 ocorre na interface entre o sólido 2CaO.SiO2 e a escória.…”

Section: Introductionunclassified

“…A formação do 2CaO.SiO2-3CaO.P2O5 ocorre na interface entre o sólido 2CaO.SiO2 e a escória. Portanto, o estudo dos mecanismos de formação dessas fases sólidas se torna importante para o entendimento completo da sua atuação no processo [5]. Através da dissolução da cal pela escória líquida ocorre a formação de fases sólidas como o silicato dicálcio (2CaO.SiO2), silicato tricálcio (3CaO.SiO2) e cálcio-ferrita (CaO.FexO).…”

Section: Introductionunclassified

Influência Das Fases Presentes Nas Misturas Iniciais E Finais Na Eficiência De Desfosforação Do Ferro-Gusa

Berger¹,

Oliveira²,

Klippel³

et al. 2017

Anais Do Seminário De Aciaria, Fundição E Metalurgia De Não-Ferrosos

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ResumoO objetivo deste artigo é analisar a influência das fases presentes nas misturas iniciais e finais na eficiência de desfosforação do ferro-gusa. Foram realizados 8 experimentos no forno de resistência, na temperatura de 1400°C, e além disso foram feitas simulações no software FactSage 6.4. Como resultado, obteu-se que as misturas DP3 e DP4 são as mais eficientes, possuindo tanto na mistura inicial quanto na final saturação em CaO, ou seja, atividade do CaO igual a 1; atividade de FeO maior possível e maior quantidade de fase líquida possível. As misturas com fases sólidas DP5 a DP8 apresentaram menor eficiência de desfosforação, pode-se concluir então que as fases sólidas diminuem a eficiência de desfosforação em processos reais, apesar de reterem mais fósforo no equilíbrio. Palavras-chave: Desfosforação; Ferro-gusa; Termodinâmica computacional. INFLUENCE OF THE PHASES PRESENT IN THE INITIAL AND FINAL MIXES IN THE DEPHOSPHORIZATION EFFICIENCY OF HOT METAL AbstractThe main objective of this paper is to analyze the influence of the phases present in the initial and final mixes in the dephosphorization efficiency of hot metal. Eight experiments were carried out in a resistance furnace, with temperature of 1400 ° C, and moreover simulations were performed in FactSage 6.4 software . As a result, it was obtained that DP3 and DP4 mixtures are the most efficient, having both the initial and final mixture saturation upon CaO, that is CaO activity equal to 1; FeO activity longest and largest possible amount of liquid phase. Mixtures with the solid phases DP5 and DP8 showed lower dephosphorization efficiency, then it can be concluded that these phases decrease the dephosphorization efficiency in real cases, although retaining phosphorus in equilibrium balance.

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“…Even so, it can be safely assumed that the primary phase that precipitates during cooling is 2CaOÁSiO 2 , and that this phase will separate with the FeO-rich liquid phase. It is known that the distribution of phosphorus in the 2CaOÁSiO 2 phase is higher than in the liquid slag phase [5][6][7][8][9][10][11][12][13][14]. If it is possible to separate the solid 2CaOÁSiO 2 phase that includes P 2 O 5 with the FeO-rich liquid phase, it will be possible to use these phases as sources of phosphorus and iron.…”

Section: Introductionmentioning

confidence: 99%

Enrichment of Phosphorus Oxide in Steelmaking Slag by Utilizing Capillary Action

Koizumi

Miki

Nagasaka

2015

J. Sustain. Metall.

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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.

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Distribution of P2O5 between Solid Solution of 2CaO·SiO2–3CaO·P2O5 and Liquid Phase

Abstract: Fig. 15. Relation between the distribution ratio of P 2 O 5 and the CaO content of the liquid at different (log g P 2 O 5 ,SS ) cal .

Cited by 103 publications

References 8 publications

Viscous Flow and Crystallization Behaviors of P-bearing Steelmaking Slags with Varying Fluorine Content

Viscous Flow and Crystallization Behaviors of P-bearing Steelmaking Slags with Varying Fluorine Content

Influência Das Fases Presentes Nas Misturas Iniciais E Finais Na Eficiência De Desfosforação Do Ferro-Gusa

Enrichment of Phosphorus Oxide in Steelmaking Slag by Utilizing Capillary Action

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