STUDY ON PHOSPHORUS REMOVAL FROM METALLURGICAL GRADE SILICON BY ACID LEACHING FOR SOLAR APPLICATION

STUDY ON PHOSPHORUS REMOVAL FROM METALLURGICAL GRADE SILICON BY ACID LEACHING FOR SOLAR APPLICATION

FREDERICCI , C.; POCO, J. G. R.; FERREIRA NETO , J. B.; NEIRA, J. B. V.

Pôster:

Metallurgical grade silicon (MG-S) contains a series of metal (Fe, Al, Mn,Cu, Ni) and non-metal (P, B) impurities which make it unsuitable for use in solar cells. Itis known that various metallic impurities are rejected by the silicon during itssolidification process, and those crystallize at grain boundaries as intermetalliccompounds. However, P is difficult to segregate in silicon, unlike most other impurities,since their partition coefficient (kp) is high (about 0.35). There are reports in theliterature indicating the possibility of phosphorus removal by the introduction ofelements that decrease the kp of P in silicon, such as calcium and barium. In this work, itwas used barium, which was introduced in MG-S as a synthesized slag with BaO/SiO2ratio of 6 and 5 wt% of CaF2 using a treatment of 1550 oC for 2 h. After melting, theingot was milled obtaining particle in the range -35+400 mesh. The particles wereleached in three steps by using water, HCl, and HF. The results showed that about 80wt% of phosphorus was removed from the silicon after leaching treatment. 

Metallurgical grade silicon (MG-S) contains a series of metal (Fe, Al, Mn,Cu, Ni) and non-metal (P, B) impurities which make it unsuitable for use in solar cells. Itis known that various metallic impurities are rejected by the silicon during itssolidification process, and those crystallize at grain boundaries as intermetalliccompounds. However, P is difficult to segregate in silicon, unlike most other impurities,since their partition coefficient (kp) is high (about 0.35). There are reports in theliterature indicating the possibility of phosphorus removal by the introduction ofelements that decrease the kp of P in silicon, such as calcium and barium. In this work, itwas used barium, which was introduced in MG-S as a synthesized slag with BaO/SiO2ratio of 6 and 5 wt% of CaF2 using a treatment of 1550 oC for 2 h. After melting, theingot was milled obtaining particle in the range -35+400 mesh. The particles wereleached in three steps by using water, HCl, and HF. The results showed that about 80wt% of phosphorus was removed from the silicon after leaching treatment. 

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DOI: 10.5151/cobeq2018-PT.0490

Referências bibliográficas

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Como citar:

FREDERICCI , C.; POCO, J. G. R.; FERREIRA NETO , J. B.; NEIRA, J. B. V. ; "STUDY ON PHOSPHORUS REMOVAL FROM METALLURGICAL GRADE SILICON BY ACID LEACHING FOR SOLAR APPLICATION", p-1855-1858. In: . São Paulo: Blucher, 2018.
ISSN 23591757, DOI 10.5151/cobeq2018-PT.0490