Investigations on hydrobromination of silicon in the presence of silicon carbide abrasives as a purification route of kerf loss waste

Tomono, Kazuaki; Furuya, Hirotoshi; Miyamoto, Seiji; Okamura, Yuki; Sumimoto, Michinori; Sakata, Yoshihisa; Komatsu, Ryuichi; Nakayama, Masaharu

doi:10.1016/j.seppur.2012.10.031

Cited by 41 publications

(23 citation statements)

References 23 publications

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“…In this respect, the loss of high-purity Si to sawing waste (containing SiC) and so on during wafer production could be 40% of the starting material. The processing of the resulting kerf loss from wafer fabrication has also been a topic of much research lately (Wang et al, 2012;Tomono et al, 2012;Tsai, 2011aTsai, , 2011bLin et al, 2010).…”

Section: Value Of Contained Metals In Pv Modulesmentioning

confidence: 99%

“…The supply of polycrystalline Si at this stage, as tabulated by the U.S. Geological Survey (USGS) in its "Mineral Yearbook for Si" (2010), shows more than twice the amount contained in c-Si PV cells up to then. Taking into account the kerf loss (at 30-40%) and breakage of Si wafers/cells during production at maximum 50% (Tomono et al, 2012;Wang et al, 2012;Tsai, 2011aTsai, , 2011bLin et al, 2010), the demand for polycrystalline Si up to 2016 should be easily met. According to the USGS Mineral Industry Survey (USGS, 2012), the resources for Si (high purity silica) are abundant around the world and the supply for Si should be more than adequate to meet the demand for all types of Si.…”

Section: Value Of Contained Metals In Pv Modulesmentioning

confidence: 99%

“…During the cutting of Si ingots for the production of Si wafers, 30-40% of Si is lost. The separation and recovery of high-purity Si from SiC and other sawing materials has been recently evaluated (Tomono et al, 2012;Wang et al, 2012;Tsai, 2011aTsai, , 2011b. The recovery of high-purity Si from kerf loss is as attractive as PV module recycling, as close to 50% of this metal is lost during wafer production.…”

Section: Introductionmentioning

confidence: 99%

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Recovering valuable metals from recycled photovoltaic modules

Kim

Tran

et al. 2014

Journal of the Air & Waste Management Association

104

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Recovering valuable metals such as Si, Ag, Cu, and Al has become a pressing issue as end-of-life photovoltaic modules need to be recycled in the near future to meet legislative requirements in most countries. Of major interest is the recovery and recycling of highpurity silicon (>99.9%) for the production of wafers and semiconductors. The value of Si in crystalline-type photovoltaic modules is estimated to be~$95/kW at the 2012 metal price. At the current installed capacity of 30 GW/yr, the metal value in the PV modules represents valuable resources that should be recovered in the future. The recycling of end-of-life photovoltaic modules would supply >88,000 and 207,000 tpa Si by 2040 and 2050, respectively. This represents more than 50% of the required Si for module fabrication. Experimental testwork on crystalline Si modules could recover a >99.98%-grade Si product by HNO 3 /NaOH leaching to remove Al, Ag, and Ti and other metal ions from the doped Si. A further pyrometallurgical smelting at 1520 C using CaO-CaF 2 -SiO 2 slag mixture to scavenge the residual metals after acid leaching could finally produce >99.998%-grade Si. A process based on HNO 3 /NaOH leaching and subsequent smelting is proposed for recycling Si from rejected or recycled photovoltaic modules.Implications: The photovoltaic industry is considering options of recycling PV modules to recover metals such as Si, Ag, Cu, Al, and others used in the manufacturing of the PV cells. This is to retain its "green" image and to comply with current legislations in several countries. An evaluation of potential resources made available from PV wastes and the technologies used for processing these materials is therefore of significant importance to the industry. Of interest are the costs of processing and the potential revenues gained from recycling, which should determine the viability of economic recycling of PV modules in the future.

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Section: Value Of Contained Metals In Pv Modulesmentioning

confidence: 99%

Section: Value Of Contained Metals In Pv Modulesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Recovering valuable metals from recycled photovoltaic modules

Kim

Tran

et al. 2014

Journal of the Air & Waste Management Association

104

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“…Many methods have been proposed to separate silicon from Si/ SiC mixtures (Drouiche et al, 2014;Li et al, 2011), which include filtration (Zhang and Ciftja, 2008), centrifugation Liu et al, 2013), phase-transfer separation (Hsu et al, 2014;Xing et al, 2013), electrophoresis and gravitational setting (Tsai, 2011;Wu and Chen, 2009), pH adjustment (Huang Contents (Tomono et al, 2013), micropore membrane (Liu et al, 2014), flotation (Huang et al, 2010;Shibata et al, 2006), high temperature treatment (Wang et al, 2008) and supercritical water (Yoko and Oshima, 2013). These approaches can increase silicon content in the slurry to 90 wt%.…”

Section: Introductionmentioning

confidence: 99%

Phase separation of a microsized powder mixture of Si and SiC by Cu–Si alloying

Huang

Zhu

2015

Chemical Engineering Science

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“…Recently, Wang et al (2012) investigated an Al-Si alloying process to remove SiC from the sawing waste and prepare an Al-Si ingot. Tomono et al (2013) used a bromination process to extract pure silicon from the sawing waste without pre-removing of SiC.…”

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

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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.

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Investigations on hydrobromination of silicon in the presence of silicon carbide abrasives as a purification route of kerf loss waste

Cited by 41 publications

References 23 publications

Recovering valuable metals from recycled photovoltaic modules

Recovering valuable metals from recycled photovoltaic modules

Phase separation of a microsized powder mixture of Si and SiC by Cu–Si alloying

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

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