COLOR DISPLAY TUBE PROCESS AND APPARATUS FOR PURIFYING SILICON

摘要

A silicon purificn. process involves maintaining molten crude silicon above its solidificn. temp. in an inert gas atmos. and introducing a liq. coolant into a rotating hollow cooling unit immersed in the silicon to cause crystallisation of high purity silicon on the outer surface of the cooling unit. Appts. for carrying out the process is also claimed. The process is used to purify metallic silicon for industrial applications (e.g. for solar cells or semiconductors), to obtain at least 99.9% purity silicon from crude silicon with 98-99% purity.