Effect of Fluorine on the Minerals Phase and Citric Acid Solubility of CaO&amp;ndash;SiO&lt;sub&gt;2&lt;/sub&gt;&amp;ndash;Fe&lt;sub&gt;&lt;i&gt;t&lt;/i&gt;&lt;/sub&gt;O&amp;ndash;P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;&amp;ndash;CaF&lt;sub&gt;2&lt;/sub&gt; System

Diao, Jiang; Xie, Bing; Wang, Yonghong; Guo, Xu

doi:10.2355/isijinternational.50.768

Cited by 30 publications

(17 citation statements)

References 10 publications

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“…Therefore, in order to enhance the phosphorus content in the enriched phase, the steelmaking slags were usually modified by different additives, such as Al 2 O 3 , SiO 2 and TiO 2 , to explore the microstructure and the enhancement of the solubility of phosphorus enriched phase. 4,5,11) Although there exists extensive literatures studying the effect of fluorine on the dephosphorus process, 12,13) the effects on the viscosity and crystallization are limited; and the kinetics of the precipitation during the continuous cooling has not been documented.…”

Section: Viscous Flow and Crystallization Behaviors Of P-bearing Steementioning

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: Viscous Flow and Crystallization Behaviors Of P-bearing Steementioning

confidence: 99%

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

et al. 2016

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“…Recently, citric acid, which is often used to test the fertility of phosphate fertilizer and steelmaking slag, 15,16) has been shown to dissolve P more effectively than nitric acid by suppressing the precipitation of HAP. 17) This suppression occurs because the Ca cations form complexes with citrate in aqueous solution, decreasing the concentration of dissolved Ca below the solubility of HAP.…”

Section: Introductionmentioning

confidence: 99%

Extraction of Phosphorus from Steelmaking Slag by Selective Leaching Using Citric Acid

Iwama

Gao

et al. 2018

ISIJ Int.

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An approach to leach phosphorus from slag was applied to commercial fertilizers made from steelmaking slag, which has relatively coarse grains. After leaching at pH 3 with citric acid, about 60% of the P 2 O 5 had been dissolved, but the dissolution ratio of MnO was less than 30%. The separation index, calculated from the dissolution ratio of P 2 O 5 divided by that of MnO, was 2.1. In addition, the dissolution ratio of the solid solution was 90% or greater. However, 25% or more of the matrix was also dissolved. To improve the selectivity of leaching, the mineralogical phases comprising the matrix were synthesized, and their leaching behaviors were investigated. The results indicate that it is important to eliminate the glassy phases and to change the valence state of iron in its oxides to 3 + to suppress the dissolution of the matrix. Finally, a synthesized slag, containing only Fe 2 O 3 as the only iron oxide, was prepared by slow cooling, and leaching tests were conducted. About 99% of the P was dissolved, but the dissolution ratio of Mn was less than 10%. In addition, the separation index increased to 14.1. In this case, the dissolution of the matrix was suppressed, and almost all the solid solution phase was dissolved.

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“…According to these investigations, many researches on enhancing the phosphorus solubility in the P-concentrating phase have been carried out by modifying steelmaking slag with different additives such as Al 2 O 3 , 7,8) SiO 2 , 9) CaF 2 , 10) and TiO 2 .…”

Section: Introductionmentioning

confidence: 99%

Isothermal Enrichment of P-Concentrating Phase from CaO–SiO2–FeO–MgO–P2O5 Melt with Super Gravity

Gao

Guo

2016

ISIJ Int.

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In this study, the investigation on the isothermal enrichment of P-concentrating phase from CaO-SiO 2 -FeO-MgO-P 2 O 5 melt with super gravity was carried out. The results show that there was an obvious stratification appearing in the sample after centrifugal enrichment. The upper part of the sample is loose and porous, while the lower part is smooth and compact. With the help of metallographic microscopy and X-ray diffraction, it is found that the P-concentrating phase gathered in the upper part, while it is hard to find any P-concentrating phase in the lower part of the sample. In addition, the volume fraction and equivalent diameter of P-concentrating phase present gradient distribution along the direction of super gravity. After centrifugal enrichment, the mass fraction of P 2 O 5 in the concentrate is up to 4.92%, while that in the tailing is just 1.08%. The recovery ratio of P 2 O 5 in the concentrate is up to 72.62% with the gravity coefficient G = 600, time t = 20 minutes and temperature T = 1 623 K.

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Effect of Fluorine on the Minerals Phase and Citric Acid Solubility of CaO–SiO<sub>2</sub>–Fe<sub><i>t</i></sub>O–P<sub>2</sub>O<sub>5</sub>–CaF<sub>2</sub> System

Cited by 30 publications

References 10 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

Extraction of Phosphorus from Steelmaking Slag by Selective Leaching Using Citric Acid

Isothermal Enrichment of P-Concentrating Phase from CaO–SiO<sub>2</sub>–FeO–MgO–P<sub>2</sub>O<sub>5</sub> Melt with Super Gravity

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