초록 ▼

A process is disclosed for purifying silicon wherein silicon in the molten state is reacted with barium carbonate and/or oxide and/or hydroxide and then, after cooling and crushing, leached with one or more dilute inorganic acids. Preferably an oxidizing gas such as oxygen or water vapor is blown in

A process is disclosed for purifying silicon wherein silicon in the molten state is reacted with barium carbonate and/or oxide and/or hydroxide and then, after cooling and crushing, leached with one or more dilute inorganic acids. Preferably an oxidizing gas such as oxygen or water vapor is blown into the molten mass during the reaction, which is conducted at a temperature in the range of from 1550°to 2000°C. The inorganic acid may be for example hydrochloric acid, hydrofluoric acid, nitric acid, sulphuric acid, or mixtures thereof.

대표청구항 ▼

A process for purifying silicon, characterized in that metallurgical silicon in the molten state is reacted with a barium compound selected from the class consisting of barium carbonate, barium oxide, barium hydroxide, and mixtures thereof at a temperature in the range of 1,550°to 2,000°C. and then,

A process for purifying silicon, characterized in that metallurgical silicon in the molten state is reacted with a barium compound selected from the class consisting of barium carbonate, barium oxide, barium hydroxide, and mixtures thereof at a temperature in the range of 1,550°to 2,000°C. and then, after cooling and crushing, the so reacted silicon is leached with a dilute inorganic acid to yield solar grade silicon having a B content not higher than 5 ppmw, and Al content lower than 1 ppmw, a P content not higher than 1 ppmw, and a total content of other metal impurities lower than 1.5 ppmw.