TY - JOUR
T1 - High-Frequency Electromagnetic Purification of Silicon
AU - Damoah, Lucas Nana Wiredu
AU - Zhang, Lifeng
N1 - Publisher Copyright:
© 2015, The Minerals, Metals & Materials Society and ASM International.
PY - 2015/9/21
Y1 - 2015/9/21
N2 - The effect of a high-frequency electromagnetic (EM) field on the removal of nonmetallic inclusions from molten silicon was experimentally investigated. Inclusion separation efficiencies of up to 99 pct were reached. The separation efficiency was independent of the particle concentration in the melt and increased significantly with increases in the frequency, separation time, and coil current. Particles were separated from the silicon matrix and relocated to the top, bottom, and side walls of the crucible due to the effect of three mechanisms: induced secondary fluid flow which carried particles from the bulk of the melt; EM body force which worked in the skin-depth area to trap particles on the side wall; and fluid shear force due to the local acceleration of molten silicon, which promoted the settling of particles to the bottom of the crucible and also carried particles toward the top. Higher coil current enhanced the strength of the magnetic field which enhanced fluid flow, while higher frequency also enhanced the fluid acceleration, and the effect of current was more pronounced leading to better particle separation.
AB - The effect of a high-frequency electromagnetic (EM) field on the removal of nonmetallic inclusions from molten silicon was experimentally investigated. Inclusion separation efficiencies of up to 99 pct were reached. The separation efficiency was independent of the particle concentration in the melt and increased significantly with increases in the frequency, separation time, and coil current. Particles were separated from the silicon matrix and relocated to the top, bottom, and side walls of the crucible due to the effect of three mechanisms: induced secondary fluid flow which carried particles from the bulk of the melt; EM body force which worked in the skin-depth area to trap particles on the side wall; and fluid shear force due to the local acceleration of molten silicon, which promoted the settling of particles to the bottom of the crucible and also carried particles toward the top. Higher coil current enhanced the strength of the magnetic field which enhanced fluid flow, while higher frequency also enhanced the fluid acceleration, and the effect of current was more pronounced leading to better particle separation.
UR - http://www.scopus.com/inward/record.url?scp=84946532250&partnerID=8YFLogxK
U2 - 10.1007/s11663-015-0447-2
DO - 10.1007/s11663-015-0447-2
M3 - Article
AN - SCOPUS:84946532250
SN - 1073-5615
VL - 46
SP - 2514
EP - 2528
JO - Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
JF - Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
IS - 6
ER -