Patent ID: 8540958
Filing Date: 2013-09-24
Classification: C01B

Abstract:
1. A method for increasing the purity of silicon, comprising: combining a first silicon-aluminum complex with a first hydrochloric acid solution to allow the first complex to react at least partially with the first hydrochloric acid solution, to provide a first mixture; separating the first mixture, to provide a third silicon-aluminum complex and the first hydrochloric acid solution; combining the third silicon-aluminum complex with a second hydrochloric acid solution to allow the third complex to react at least partially with the second hydrochloric acid solution, to provide a third mixture, wherein the second hydrochloric acid solution is stronger than the first hydrochloric acid solution; separating the third mixture, to provide a first silicon and the second hydrochloric acid solution; transferring portions of the second hydrochloric acid solution to the first hydrochloric acid solution to maintain the pH of the first hydrochloric acid solution, the volume of the first hydrochloric acid solution, the specific gravity of the first hydrochloric acid solution, or a combination thereof; combining the first silicon with a first rinse solution, to provide a fourth mixture; separating the fourth mixture, to provide a wet purified silicon and the first rinse solution; drying the wet purified silicon, sufficient to provide a dry purified silicon.