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Thermodynamic criteria of the end-of-life silicon wafers refining for closing the recycling loop of photovoltaic panels.

Authors :
Lu X
Miki T
Takeda O
Zhu H
Nagasaka T
Source :
Science and technology of advanced materials [Sci Technol Adv Mater] 2019 Jul 10; Vol. 20 (1), pp. 813-825. Date of Electronic Publication: 2019 Jul 10 (Print Publication: 2019).
Publication Year :
2019

Abstract

The collected end-of-life (EoL) silicon wafers from the discharged photovoltaic (PV) panels are easily contaminated by impurities such as doping elements and attached materials. In this study, the thermodynamic criteria for EoL silicon wafers refining using three most typical metallurgical refining processes: oxidation refining, evaporation refining, and solvent refining were systemically and quantitatively evaluated. A total of 42 elements (Ag, Al, Au, B, Be, Bi, C, Ca, Ce, Co, Cr, Cu, Fe, Ga, Gd, Ge, Hf, In, La, Mg, Mn, Mo, Na, Nb, Ni, Os, P, Pb, Pd, Pt, Re, Ru, Sb, Sn, Ta, Ti, U, V, W, Y, Zn, Zr) that are likely to be contained in the collected EoL silicon-based PV panels were considered. The principal findings are that the removal of aluminum, beryllium, boron, calcium, gadolinium, hafnium, uranium, yttrium, and zirconium into the slag, and removal of antimony, bismuth, carbon, lead, magnesium, phosphorus, silver, sodium, and zinc into vapor phase is possible. Further, solvent refining process using aluminum, copper, and zinc as the solvent metals, among the considered 14 potential ones, was found to be efficient for the EoL silicon wafers refining. Particularly, purification of the phosphorus doped n -type PV panels using solvent metal zinc and purification of the boron doped p -type PV panels using solvent metal aluminum are preferable. The efficiency of metallurgical processes for separating most of the impurity elements was demonstrated, and to promote the recycling efficiency, a comprehensive management and recycling system considering the metallurgical criteria of EoL silicon wafers refining is critical.

Details

Language :
English
ISSN :
1468-6996
Volume :
20
Issue :
1
Database :
MEDLINE
Journal :
Science and technology of advanced materials
Publication Type :
Academic Journal
Accession number :
31489054
Full Text :
https://doi.org/10.1080/14686996.2019.1641429