Methods of recycling silicon swarf into electronic grade polysilicon or metallurgical-grade silicon
AssigneesSunPower Corporation, Total Solar International
InventorsMoon Chun, Christoph SACHS, David VERSTRAETEN
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Abstract
Methods of recycling silicon swarf into electronic grade polysilicon or metallurgical-grade silicon are described herein are described. In an example, a method includes cutting a silicon ingot and recovering silicon swarf having a first purity from the cutting process. The recovered silicon is purified in an upgraded metallurgical silicon process to produce electronic grade polysilicon particles having a second purity higher than the first purity. The upgraded metallurgical silicon process can include dissolving the recovered silicon particles in a molten aluminum metal smelt.
Claims10
(canceled)
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 trichlorosilane;
- 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.
Dependencies are inferred from the claim text.