Patent ID: 7232544
Filing Date: 2007-06-19
Classification: B01D,B01J,C01B,Y02P

Abstract:
1. In an apparatus for continuous slag treatment of molten silicon for removal of one a more impurity elements from the silicon, the apparatus comprising a vessel intended to contain molten silicon and liquid slag the vessel has an upwardly extending overflow for slag connected to an outlet opening for slag is the bottom of the vessel, and means for supplying heat energy to the vessel, the improvement comprising: an open-ended pipe arranged about and at a distance from the overflow such that there is an annulus between the pipe and the overflow, which pipe extends upwards to a level above the top of the overflow and downwards to the bottom of the vessel, the pipe having at least one opening at the bottom of the vessel, a closeable outlet opening for treated silicon in the sidewall of the vessel, and means for intermittent supplying solid or molten silicon to the vessel and means for continuous or substantially continuous supplying solid or liquid slag to the top of the vessel.