Phosphorus Removal from Si-Fe Alloy Using SiO2-Al2O3-CaO Slag

Hosseinpour, Ali; Khajavi, Leili Tafaghodi

doi:10.1007/s11663-019-01586-0

Cited by 12 publications

(8 citation statements)

References 30 publications

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“…A comparative evaluation was performed to examine the results of the current study with respect to the previous investigations that used different solvent and/or slag compositions. 4,34 The D P values obtained in this study along with the ones acquired from the previous studies are plotted in Fig. 7.…”

mentioning

confidence: 89%

“…4 The maximum L P value achieved in the current work is higher than the one obtained by employing a similar Si-20 wt.% Fe alloy and CaO-SiO 2 -Al 2 O 3 ternary slag at 1600°C. 34…”

Section: Effect Of Basicitymentioning

confidence: 99%

“…The maximum L P value of 0.23 was achieved using 20% Fe in the alloy. 34 Solvent refining with Cu combined with slag treatment using a quaternary CaO-SiO 2 -Al 2 O 3 -Na 2 O system at 1500°C resulted in a maximum L P value of 1.1. 4 The present study is focused on P removal from Si-Fe alloy using quaternary CaO-SiO 2 -Al 2 O 3 -Na 2 O slag at 1300°C.…”

Section: Introductionmentioning

confidence: 96%

“…Hosseinpour and Tafaghodi used the same alloy, i.e., Si-20 wt.% Fe, while employing a ternary slag of CaO-Al 2 O 3 -SiO 2 at 1500°C. 34 Li, Utigard and Barati worked with Si-70 wt.% Cu alloy and quaternary slag of CaO-Al 2 O 3 -SiO 2 -Na 2 O at 1500°C. 4 The results of all these studies show a direct relationship between D P and K corr .…”

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confidence: 99%

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Removal of Phosphorus from Si-Fe Alloy by CaO-Al2O3-SiO2-Na2O Slag Refining

Taposhe

Khajavi

2021

JOM

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A combination of slag and solvent refining methods was used to remove phosphorus from silicon. The CaO-Al 2 O 3-SiO 2-Na 2 O quaternary system was selected as the slag to eliminate phosphorus from Si-20 wt.% Fe alloy at 1300°C. The partition ratio of phosphorus (L P) at various slag compositions was obtained to investigate the effect of basicity (CaO/SiO 2), oxygen potential (SiO 2 /Al 2 O 3) and Na 2 O content of the slag. The maximum value for L P was 1.19 at CaO/SiO 2 of 1.36, SiO 2 /Al 2 O 3 of 1.56 and the addition of 10 wt.% of Na 2 O. The critical partial pressure of oxygen for maximum phosphorus removal was estimated at 1.8 9 10 À22 atm. The normalized distribution and phosphate capacity were evaluated to clarify the effect of basicity. Corrected optical basicity and NBO/T were determined to consider the effect of the cations in the complex silicate structures and investigate the effect of the degree of depolymerization on the efficiency of phosphorus removal from silicon.

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mentioning

confidence: 89%

“…4 The maximum L P value achieved in the current work is higher than the one obtained by employing a similar Si-20 wt.% Fe alloy and CaO-SiO 2 -Al 2 O 3 ternary slag at 1600°C. 34…”

Section: Effect Of Basicitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

mentioning

confidence: 99%

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Removal of Phosphorus from Si-Fe Alloy by CaO-Al2O3-SiO2-Na2O Slag Refining

Taposhe

Khajavi

2021

JOM

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“…To date, considerable work has been done to investigate the effect of slag properties on the B removal efficiency. A number of slag systems have been studied and reviewed, [7,[11][12][13][14] such as CaO-SiO 2 , [15][16][17][18][19] CaO-MgO-SiO 2 , [20][21][22] CaO-BaO-SiO 2 , [6,18] CaO-Na 2 O-SiO 2 , [5,23,24] CaO-ZnO-SiO 2 , CaO-Al 2 O 3 -SiO 2 , [25][26][27] CaO-MgO-Al 2 O 3 -SiO 2 , [28,29] CaO-SiO 2 -CaCl 2 , [30][31][32] CaO-SiO 2 -CaF 2 , [24,33,34] and so on. The B removal ability of different slags can be evaluated by the widely used B distribution coefficient (L B ) between the slag and metal in molten state:…”

Section: Introductionmentioning

confidence: 99%

Effects of La2O3 Addition into CaO-SiO2 Slag: Structural Evolution and Impurity Separation from Si-Sn Alloy

Zhu

Azarov

et al. 2021

Metall Mater Trans B

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Boron (B) and phosphorus (P) are the most problematic impurities to be removed in the production of solar-grade silicon by the metallurgical process. In this work, the distribution of B and P between CaO-(La2O3)-SiO2 slags and Si-10 mass pct Sn melt was experimentally studied. B distribution coefficient increased from 2.93 in binary CaO-SiO2 slag to 3.33 and 3.65 with 2 and 10 mass pct La2O3 additions, respectively. In the followed acid-leaching experiments, the slag-treated Si-Sn alloys exhibited higher B and P removal than that of the initial alloy without slag treatment. Molecular dynamics simulations were performed to study the effect of La2O3 addition on the slag structural and transport properties. A novel oxygen classification method was proposed to distinguish the different structural roles of La and Ca in the CaO-La2O3-SiO2 system. It was found that La3+ prefers to stay in the depolymerized region, mostly connects with 6-7 non-bridging oxygen, and requires a weak charge compensation with Ca2+. Possible silicothermic reduction was evaluated to discuss the slag chemistry and the mass transfer between slag and metal phase. A thermodynamic model was derived to theoretically study the alloying effect on impurity distribution in slag refining where positive interaction coefficient and high alloying concentration were found most beneficial to improve the impurity removal.

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