Abstract: Metallurgical grade silicon is melted and the resulting impure molten metal is continuously flowed downwardly as a thin film through an atmosphere of impurity-reactive gas or gases directly into a crucible, wherein it is subjected to directional solidification. The preferred apparatus for carrying out the process comprises a heated reaction chamber fed peripherally from a superimposed melting chamber, the reaction chamber having horizontally rippled interior wall surfaces of a substantially non-reactive material, such as graphite, silicon carbide, or silicon nitride, so the descending film of molten metal will be agitated and spread laterally. Means are provided for introducing the reactive gas or gases near the bottom of the reaction chamber and for exhausting the spent gas at the top. The reaction chamber is superimposed above and in vertically spaced relationship with an electric furnace, which encircles a columnar crucible.

Abstract: The present invention relates to a new type of electric furnace and process for its use for highest purity melting of certain metals and semiconductor materials, particularly it is well suited for melting materials that would react chemically with standard refractory crucible materials thus potentially resulting in a contamination of such melt.