Abstract: A siloxane composition, comprising from 70 to 99 parts by weight of a solid particulate having a median particle size of from 0.1 to 3000 ?m and from 1 to 30 parts by weight of a binder having a median particle size of from 5 to 250 ?m, wherein the composition is a powder and the binder comprises a siloxane resin having the formula: (R13SiO1/2)w(R12SiO2/2)x(R1SiO3/2)y(SiO4/2)z, wherein each R1 is independently selected from hydrogen, hydrocarbyl, substituted hydrocarbyl, —O?NR2R3, —OR2, —O—R4—OR2, and an epoxy-substituted organic group, wherein R2 is C1 to C8 hydrocarbyl, R3 is R2 or —H, R4 is hydrocarbylene, w+x+y+z=1, y/(w+x+y+z) is at least 0.67, and the siloxane resin has a softening point of from 30 to 115° C.; an agglomerate, and a method preparing the agglomerate.

Abstract: Metallurgical grade silicon is purified by removing metallic impurities and non-metallic impurities. The object is to produce a silicon species that is suitable for use as solar grade silicon. The process involves grinding metallurgical grade silicon containing metallic and non-metallic impurities to a silicon powder consisting of particles of silicon having a diameter of less than about 5 millimeter. While maintaining the ground silicon powder in the solid state, the ground silicon powder is heated to a temperature less than the melting point of silicon (1410° C.) under reduced pressure. The heated ground silicon powder is maintained at that temperature for a period of time sufficient to enable at least one metallic or non-metallic impurity to be removed from the metallurgical grade silicon.