US 11,791,435 B2
Methods of recycling silicon swarf into electronic grade polysilicon or metallurgical-grade silicon
Moon Chun, San Jose, CA (US); Christoph Sachs, Buc (FR); and David Verstraeten, Palo Alto, CA (US)
Assigned to Maxeon Solar Pte. Ltd., Singapore (SG)
Filed by Maxeon Solar Pte. Ltd., Singapore (SG)
Filed on Dec. 27, 2022, as Appl. No. 18/89,473.
Application 18/089,473 is a continuation of application No. 16/500,350, abandoned, previously published as PCT/US2018/012831, filed on Jan. 8, 2018.
Claims priority of provisional application 62/487,452, filed on Apr. 19, 2017.
Claims priority of provisional application 62/487,447, filed on Apr. 19, 2017.
Prior Publication US 2023/0136895 A1, May 4, 2023
Int. Cl. C01B 33/037 (2006.01); H01L 31/18 (2006.01); B28D 5/04 (2006.01); H01L 31/028 (2006.01)
CPC H01L 31/1804 (2013.01) [B28D 5/042 (2013.01); C01B 33/037 (2013.01); H01L 31/028 (2013.01); C01P 2002/52 (2013.01); C01P 2004/61 (2013.01); C01P 2006/40 (2013.01); C01P 2006/80 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method of purifying silicon, the method comprising:
subjecting silicon particles having a first purity to a silicon dioxide reduction operation to form a first product;
combining the first product with a hydrochloric acid source in a fluid bed reactor and expelling hydrogen gas at the fluid bed reactor to form trichorosilane;
subjecting the trichlorosilane to a dust filtration process;
subsequent to subjecting the trichlorosilane to the dust filtration process, subjecting the trichlorosilane to a trichlorosilane condensation process to form a second product;
distilling the second product to form purified trichlorosilane;
processing the purified trichlorosilane through a silicon evaporator and introducing hydrogen to form a third product; and
processing the third product through a chemical vapor deposition reactor to form silicon particles having a second purity greater than the first purity.