Purification of solar cell silicon materials through filtration

Ciftja, Arjan; Zhang, Lifeng; Engh, Thorvald Abel; Kvithyld, Anne

doi:10.1016/s1001-0521(07)60070-9

Cited by 25 publications

(11 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the size of silicon particles in the slurry was much smaller, and it is difficult to separate those fine silicon particles from the SiC particles in the equivalent size. The possible methods to recycle silicon from SoG-Si slurry wastes and to purify the SoG-Si and its wastes will be discussed include methods to remove non-metallic particles from the melt (such as sedimentation, bubble flotation [31][32] , centrifugal separation [33] , filtration [20][21][22][23][24] , electromagnetic separation, and directional solidification) and methods to remove metallic and other dissolved impurities (such as acid leaching, gas blowing (Cl 2 , O 2 [34] , SiCl 4 , etc), plasma refining [35] , evaporation [36] , electron-beam furnace [35] , fractional melting process [37] , and solidification control.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Development of Solar Grade Silicon (SoG-Si) Feedstock by Recycling SoG-Si Wastes

Zhang¹,

Dong²,

Damoah³

2013

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

“…Zhang et al has successfully recycled these SoG-Si scraps through high temperature filtration. [20][21][22][23][24] Fig. 6 Typical top-cut SoG-Si scraps…”

Section: -Wastes From Sog-si Ingot Top-cut Scrapsmentioning

confidence: 99%

Development of Solar Grade Silicon (SoG-Si) Feedstock by Recycling SoG-Si Wastes

Zhang¹,

Dong²,

Damoah³

2013

View full text Add to dashboard Cite

“…Shibata et al (2006) also used a flotation method to obtain SiC from sawing wastes. Ciftja et al (Ciftja et al, 2006;Zhang and Ciftja, 2008) investigated the removal of SiC and Si 3 N 4 from top-cut solar cell Si scraps by filtration with foam filters. Wang et al (2008Wang et al ( , 2009) developed a process for purifying the Si obtained from sawing wastes.…”

Section: Introductionmentioning

confidence: 99%

Recycling silicon wire-saw slurries: Separation of silicon and silicon carbide in a ramp settling tank under an applied electrical field

Tsai

Shih

2013

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

The growing demand for silicon solar cells in the global market has greatly increased the amount of silicon sawing waste produced each year. Recycling kerf Si and SiC from sawing waste is an economical method to reduce this waste. This study reports the separation of Si and SiC using a ramp settling tank. As they settle in an electrical field, small Si particles with higher negative charges have a longer horizontal displacement than SiC particles in a solution of pH 7, resulting in the separation of Si and SiC. The agreement between experimental results and predicted results shows that the particles traveled a short distance to reach the collection port in the ramp tank. Consequently, the time required for tiny particles to hit the tank bottom decreased, and the interference caused by the dispersion between particles and the fluid motion during settling decreased. In the ramp tank, the highest purities of the collected SiC and Si powders were 95.2 and 7.01 wt%, respectively. Using a ramp tank, the recycling fraction of Si-rich powders (SiC <15 wt%) reached 22.67% (based on the whole waste). This fraction is greater than that achieved using rectangular tanks.Implications: Recycling Si and SiC abrasives from the silicon sawing waste is regarded as an economical solution to reduce the sawing waste. However, the separation of Si and SiC is difficult. This study reports the separation of Si and SiC using a ramp settling tank under an applied electrical field. As they settle in an electrical field, small Si particles with higher negative charges have a longer horizontal displacement than SiC particles in a solution of pH 7, resulting in the separation of Si and SiC. Compared with the rectangular tanks, the recycling fraction of Si-rich powders using a ramp tank is greater, and the proposed ramp settling tank is more suitable for industrial applications.

show abstract

“…[4,5] The use and the evaluation of the efficiency of ceramic foam filters (CFFs) in the removal of nonmetallic inclusions from molten aluminum have been studied widely in the literatures. [6][7][8][9][10][11][12][13][14] Reports from these studies indicated that CFFs are capable of achieving high aluminum filtration efficiencies and the formation of bridge-like structures of inclusions at the top area of the filter contributes to the high efficiencies. It is well known that CFFs also remove inclusions smaller than the pore size of the filter in a deep-bed filtration mode.…”

Section: Introductionmentioning

confidence: 99%

Removal of Inclusions from Aluminum Through Filtration

Damoah

Zhang

2010

Metall Mater Trans B

View full text Add to dashboard Cite

Filtration experiments were carried out using both an AlF 3 slurry-coated and an uncoated Al 2 O 3 ceramic foam filter to study the removal of nonmetallic inclusions and impurity elements. The results showed that the 30-ppi ceramic foam filter removed up to 85 pct inclusions from aluminum. Several pictures of two-and three-dimensional morphologies of both nonmetallic and intermetallics inclusions also have been presented. The following contributing mechanisms for the removal of nonmetallic inclusions in the deep-bed filtration mode are proposed:(1) collision with walls and interception effect and (2) the formation of both intermetallic and nonmetallic inclusion bridges during filtration. Fluid dynamics modeling of inclusion attachment to the filter walls showed that most inclusions, especially those with larger sizes, are entrapped at the upper part of the filter, whereas smaller inclusions are dispersed well throughout the filter. The calculated inclusions removal fractions for the 30-ppi filter showed that almost all inclusions>125 lm are removed, and inclusions~5 lm in size are removed up to 85 pct. The interfacial energy between two collided same-size inclusions was calculated, indicating that a strong clustering of inclusions may result within the filter window. Magnesium impurities were removed up to 86 pct by the AlF 3 slurry-coated filter. The filter acted in active filtration mode in addition to the contribution of the air oxidation of dissolved [Mg], which was calculated to be 13 pct. The total mass transfer coefficient of dissolved [Mg] to the reaction interface was calculated to be 1.15 9 10 À6 m/s.

show abstract

Purification of solar cell silicon materials through filtration

Cited by 25 publications

References 4 publications

Development of Solar Grade Silicon (SoG-Si) Feedstock by Recycling SoG-Si Wastes

Development of Solar Grade Silicon (SoG-Si) Feedstock by Recycling SoG-Si Wastes

Recycling silicon wire-saw slurries: Separation of silicon and silicon carbide in a ramp settling tank under an applied electrical field

Removal of Inclusions from Aluminum Through Filtration

Contact Info

Product

Resources

About