Abstract: A self-baking electrode includes a cylindrical shroud having a longitudinal central axis A. The shroud is made of an electrically-conductive material and disposed vertically on top of a vat of the furnace over one length of the self-baking electrode. The electrode includes a central column disposed within the shroud, substantially aligned on the longitudinal axis A. The central column is suspended from a device independent of the shroud such that the central column is adapted to slip in vertical translation within the shroud and a crude carbonaceous paste disposed around the central column in a top portion of the shroud. The paste is softened and baked under an effect of heat into a stiff carbonaceous paste sticking to the central column in a bottom portion of the shroud. The central column includes a series of electrically-conductive carbonaceous elongate elements. The carbonaceous elongate elements are flexible.

Abstract: A self-baking electrode includes a cylindrical shroud having a longitudinal central axis A. The shroud is made of an electrically-conductive material and disposed vertically on top of a vat of the furnace over one length of the self-baking electrode. The electrode includes a central column disposed within the shroud, substantially aligned on the longitudinal axis A. The central column is suspended from a device independent of the shroud such that the central column is adapted to slip in vertical translation within the shroud and a crude carbonaceous paste disposed around the central column in a top portion of the shroud. The paste is softened and baked under an effect of heat into a stiff carbonaceous paste sticking to the central column in a bottom portion of the shroud. The central column includes a series of electrically-conductive carbonaceous elongate elements. The carbonaceous elongate elements are flexible.

Abstract: The invention concerns a method for producing a medium purity silicon comprising: preparing, by carbothermic reduction of silica in a submerged arc-furnace a silicon with low boron content; refining the liquid silicon with oxygen or chlorine; treating the refined silicon under reduced pressure from 10 to 100 Pa with neutral gas injection; segregated solidification. The invention also concerns a medium purity silicon designed to serve as raw material for making silicon of electronic or voltaic quality, and having (in weight fractions): a total of impurities ranging between 100 and 400 ppm, with the content in metallic elements ranging between 30 and 300 ppm; a boron content from 1 to 10 ppm; a phosphorus/boron ratio ranging between 0.5 and 1.5.