Numerical Simulation of Phosphorus Removal from Silicon by Induction Vacuum Refining

Zheng, Songsheng; Engh, Thorvald Abel; Tangstad, Merete; Luo, Xuetao

doi:10.1007/s11661-011-0621-3

Cited by 43 publications

(20 citation statements)

References 22 publications

(26 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For the present study, the silicon melt is hold in the graphite crucible and the induction takes place also in the crucible and it may affect the calculations done by Eq. (12). The authors, however, has modeled the induction melting of silicon in the graphite crucible by Comsol multiphysics simulation software and the calculated velocities are close to the results of applying Eq.…”

Section: Mass Transfer In the Melt Boundary Layersupporting

confidence: 53%

“…Zheng et al [12] have recently developed a numerical approach for calculating this parameter, where the mass transfer coefficient of phosphorus in the gas phase is calculated considering the diffusivities of both Si and P in the gas phase. In the present study, however, the mass transfer resistance in the gas phase (1=k g / is simply calculated by subtracting the determined mass transfer resistances 1=k m and 1=k c from the total mass transfer resistance 1=k P as seen in Table 2.…”

Section: Mass Transfer In the Gas Phasementioning

confidence: 99%

“…The application of vacuum induction melting in lower pressures than 0.1 Pa and different temperatures up to 1600 ı C has also shown phosphorus removal from 15 ppmw to below 1 ppmw within two hours [11]. A numerical simulation on the phosphorus removal from silicon in vacuum induction refining has been recently developed by Zheng et al [12] and the effects of different parameters on phosphorus removal has been evaluated.…”

Section: Introductionmentioning

confidence: 99%

“…The vacuum refining of MG-Si using electron beam gun and induction melting has been studied through the previous works [4][5][6][7][8][9][10][11][12]. Although silicon content in MG-Si is around 99 wt%, the composition of the impurities varies with regard to the compositions of the raw materials used for silicon production.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Kinetics and Mechanism of Phosphorus Removal from Silicon in Vacuum Induction Refining

Safarian

Tangstad

2012

High Temperature Materials and Processes

Self Cite

View full text Add to dashboard Cite

Abstract. Vacuum induction refining is a process that can be applied to remove phosphorus from molten silicon for the production of solar grade silicon. Pure silicon was doped by phosphorus to make molten silicon containing around 17 ppmw phosphorus. The kinetics of phosphorus removal from this silicon was studied at 0.5 Pa through the application of vacuum induction refining. It was observed that vacuum removal of phosphorus occurs through a first-order reaction. The rate constants of phosphorus evaporation were determined as 2.28 10 6 m=s and 4.93 10 6 m=s at 1500 ı C and 1600 ı C, respectively. Moreover, an apparent activation energy 213.1 kJ=mol for phosphorus evaporation from molten silicon was calculated. It was found that mass transfer of phosphorus in the melt is not rate limiting in the inductively stirred silicon melt. The vacuum removal of phosphorus is mix-controlled by chemical reaction and gas phase mass transfer. Under medium vacuum conditions, the mass transfer in the gas phase is more rate-limiting than the chemical reaction at higher refining temperatures.

show abstract

Section: Mass Transfer In the Melt Boundary Layersupporting

confidence: 53%

Section: Mass Transfer In the Gas Phasementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Kinetics and Mechanism of Phosphorus Removal from Silicon in Vacuum Induction Refining

Safarian

Tangstad

2012

High Temperature Materials and Processes

Self Cite

View full text Add to dashboard Cite

show abstract

“…A more cost-effective and energy-efficient alternative to produce SOG-Si is to use a metallurgical process, which provides sustainability and a number of benefits in terms of productivity and process cost. Metallurgical methods such as directional solidification [1][2][3], alloy refining [4][5][6], oxidation with plasma melting [7,8], and vacuum melting [9,10] have all been investigated; however, each has its own unique limitations that prevent the total removal of impurities. This is largely a result of the fact that the segregation coefficients of B and P are both close to 1 in molten Si, meaning that they are not easily removed from the melt.…”

Section: Introductionmentioning

confidence: 99%

Reaction Mechanism and Kinetics of Boron Removal from Molten Silicon by CaO–SiO2–CaCl2 Slag Treatment

Wang

Morita

2015

J. Sustain. Metall.

View full text Add to dashboard Cite

The mechanism by which B is removed from Si to a molten CaO-SiO 2 -CaCl 2 slag, and its subsequent evaporation to a gas phase at 1723 K, has been evaluated with a view to optimize the production of solar-grade Si. By assuming a diffusion model for the transfer of B from Si to molten slag, and its evaporation to a gas phase, the diffusion coefficient of B in slag was investigated using the tube-molten pool method. The mass transfer coefficients of B in slag were also measured and calculated according to Fick's law. Through this, it was found that the rate-limiting step of B removal in the slag refining process is controlled by B transfer from both the slag interface and surface. Of these, however, it is the former that has the greater influence, as the slag boundary layers in the interface are thicker than those at the surface.

show abstract

Clean Synthesis and Formation Mechanisms of High‐Purity Silicon for Solar Cells by the Carbothermic Reduction of SiC with SiO₂

et al. 2019

View full text Add to dashboard Cite

Metallurgical synthesis of solar grade silicon (SoGÀ Si) is an existing challenge due to the strict chemical composition of silicon for solar cells. Here, we report a green and facile approach to synthesize high-purity silicon (99.98 wt%, 0.12 ppmw B and 0.18 ppmw P) for solar cells by the carbothermic reduction of SiC with SiO 2 in a vacuum graphite resistance furnace. Catalyst of Fe 2 O 3 plays the role of reducing the concentration of CO (g) , lowering the energy consumption and improving the purity and yield of silicon. The present work is one-step to obtain silicon with less B and P, but it is composed of silicon synthesis, oxidation refining, vacuum refining and blowing refining, which discloses an innovative chemical concepts of in-situ synthesis combined with refining. According to the characterizations of the reacted SiC particles performed by XRD, Raman, PL, XPS, SEM and TEM, the morphologies and formation mechanisms of the in-situ silicon from the horizons of atomic scale were revealed for the first time. It was evidenced conclusively that the SiÀ C bonding is broken from the (006) planes of 6H-SiC at 1850°C by the reaction of SiC (s) + 2SiO 2(l) = 3SiO (g) + CO (g) , and then the silicon nucleates on the (101) planes of 6H-SiC and grows along the [111] direction at 1950°C via the vapor-solid reaction of SiO (g) + SiC (s) = 2Si (l) + CO (g) .High-purity SiO 2 (low content of B and P) can be achieved relatively easily, whereas it is difficult for carbon materials. Herein, it is urgent to use a high-purity reducing agent. [23,24] In fact, the actual reduction process of reaction (1) is much more complicated, which includes the formation of intermediate species, such as SiO (g) and SiC. Meanwhile, SiC is a significant reactant for the production of silicon. [25,26] The concentration of B and P in SiC can be controlled under 0.1 ppmw, [27] which meets the required level for solar cells. Herein, high-purity SiC is proposed as the reducing agent.

show abstract

Numerical Simulation of Phosphorus Removal from Silicon by Induction Vacuum Refining

Cited by 43 publications

References 22 publications

Kinetics and Mechanism of Phosphorus Removal from Silicon in Vacuum Induction Refining

Kinetics and Mechanism of Phosphorus Removal from Silicon in Vacuum Induction Refining

Reaction Mechanism and Kinetics of Boron Removal from Molten Silicon by CaO–SiO2–CaCl2 Slag Treatment

Clean Synthesis and Formation Mechanisms of High‐Purity Silicon for Solar Cells by the Carbothermic Reduction of SiC with SiO₂

Contact Info

Product

Resources

About

Numerical Simulation of Phosphorus Removal from Silicon by Induction Vacuum Refining

Cited by 43 publications

References 22 publications

Kinetics and Mechanism of Phosphorus Removal from Silicon in Vacuum Induction Refining

Kinetics and Mechanism of Phosphorus Removal from Silicon in Vacuum Induction Refining

Reaction Mechanism and Kinetics of Boron Removal from Molten Silicon by CaO–SiO2–CaCl2 Slag Treatment

Clean Synthesis and Formation Mechanisms of High‐Purity Silicon for Solar Cells by the Carbothermic Reduction of SiC with SiO2

Contact Info

Product

Resources

About

Clean Synthesis and Formation Mechanisms of High‐Purity Silicon for Solar Cells by the Carbothermic Reduction of SiC with SiO₂