Abstract: Provided is a silicon refining device that is used when industrially producing silicon of high purity by vacuum melting, has a high P removal rate and thus high productivity, and is a practical device cost-wise with a simple and cheap device configuration. This silicon refining device comprises, in a decompression vessel provided with a vacuum pump, a crucible that contains a metal silicon material, a heating device that heats the crucible, and a molten metal surface thermal insulation member that covers the upper portion of silicon molten metal and has an exhaust opening with an opening area that is smaller than the silicon molten metal surface area. The molten metal surface thermal insulation member comprises a laminated insulation material with a multilayer structure in which three or more laminates are laminated at predetermined intervals from each other, and which exhibits a radiant heat insulating function based on the multilayer structure.

Abstract: Provided are: a method for manufacturing a highly pure silicon by unidirectional solidification of molten silicon, that can inexpensively and industrially easily manufacture highly pure silicon that has a low oxygen concentration and low carbon concentration and is suitable for applications such as manufacturing solar cells; highly pure silicon obtained by this method; and silicon raw material for manufacturing highly pure silicon. A method for manufacturing highly pure silicon using molten silicon containing 100 to 1000 ppmw of carbon and 0.5 to 2000 ppmw of germanium as the raw material when manufacturing highly pure silicon by unidirectionally solidifying molten silicon raw material in a casting container, the highly pure silicon obtained by this method, and the silicon raw material for manufacturing the highly pure silicon.

Abstract: In this method for refining silicon by vacuum melting, the falling of impurity condensate from an impurity trap located above a crucible and contamination of the molten silicon are prevented. A crucible for housing molten silicon, and a heating means for heating the crucible are located inside a treatment chamber equipped with a vacuum pump; further provided are: an impurity trap having an impurity condensation unit for cooling and condensing the vapor of impurities evaporating from the liquid surface of the molten silicon; and a contamination prevention device for preventing contamination of the molten silicon, having an impurity catch unit for catching impurities when impurities trapped by the impurity trap fall.

Abstract: An objective of the present invention is, in refining a metal or a semiconductor melt, without impairing refining efficiency, to alleviate wear and tear commensurate with unevenness in a crucible caused by instability in melt flow, and to allow safe operation over long periods of time such that leakages from the crucible do not occur. Provided is a metal or semiconductor melt refining method, in which, by using an AC resistance heating heater as a crucible heating method, the melt is heat retained and mixed by a rotating magnetic field which is generated by the resistance heating heater.

Abstract: Provided are a silicon purification apparatus that uses a ring-shaped thermal-insulating lid, which can be replaced while heating a crucible, as a thermal-insulating means for keeping the surface of a silicon melt at a high temperature, and has a simple structure and is easy to produce, said silicon purification apparatus being capable of continuously processing several tens of portions of charged silicon with the crucible heated as is; a silicon purification method that makes use of the silicon purification apparatus; and a purification method.

Abstract: In this method for refining silicon by vacuum melting, the falling of impurity condensate from an impurity trap located above a crucible and contamination of the molten silicon are prevented. A crucible for housing molten silicon, and a heating means for heating the crucible are located inside a treatment chamber equipped with a vacuum pump; further provided are: an impurity trap having an impurity condensation unit for cooling and condensing the vapor of impurities evaporating from the liquid surface of the molten silicon; and a contamination prevention device for preventing contamination of the molten silicon, having an impurity catch unit for catching impurities when impurities trapped by the impurity trap fall.

Abstract: Provided is a silicon refining device that is used when industrially producing silicon of high purity by vacuum melting, has a high P removal rate and thus high productivity, and is a practical device cost-wise with a simple and cheap device configuration. This silicon refining device comprises, in a decompression vessel provided with a vacuum pump, a crucible that contains a metal silicon material, a heating device that heats the crucible, and a molten metal surface thermal insulation member that covers the upper portion of silicon molten metal and has an exhaust opening with an opening area that is smaller than the silicon molten metal surface area. The molten metal surface thermal insulation member comprises a laminated insulation material with a multilayer structure in which three or more laminates are laminated at predetermined intervals from each other, and which exhibits a radiant heat insulating function based on the multilayer structure.

Abstract: Provided are a method for manufacturing a highly pure silicon by unidirectional solidification of molten silicon, that can inexpensively and industrially easily manufacture highly pure silicon that has a low oxygen concentration and low carbon concentration and is suitable for applications such as manufacturing solar cells; highly pure silicon obtained by this method and silicon raw material for manufacturing highly pure silicon. A method for manufacturing highly pure silicon using molten silicon containing 100 to 1000 ppmw of carbon and 0.5 to 2000 ppmw of germanium as the raw material when manufacturing highly pure silicon by unidirectionally solidifying molten silicon raw material in a casting container, the highly pure silicon obtained by this method, and the silicon raw material for manufacturing the highly pure silicon.