Toho Titanium Co., Ltd.

Nippon Steel Materials Co., Ltd.

Nobuaki Ito

Masanori Yamaguchi

Kenichi Kato

Shigeo Ampo

Masaki Okajima

Shinji Tokumaru

Kensuke Okazawa

The present invention provides a high purity silicon production system and production method suitable for using inexpensive metallurgical grade metal silicon as a material and using the slag refining method to produce high purity silicon with a purity of 6N or more suitable for solar battery applications, in particular, high purity silicon with a boron content of at least not more than 0.3 mass ppm, inexpensively on an industrial scale, that is, a high purity silicon production system and production method using the slag refining method wherein a direct electromagnetic induction heating means having the function of directly heating the molten silicon in the crucible by electromagnetic induction is arranged outside the outside wall surface of the above crucible and the crucible is formed by an oxidation resistant material at least at a region where the molten silicon contacts the crucible inside wall surface at the time of not powering the direct electromagnetic induction heating means.

High purity silicon production system and production method

An object of the invention is to provide a method for producing a large amount of inexpensive high purity silicon useful for a solar battery. Disclosed is a method for producing high purity silicon by migrating impurities in silicon to slag including performing a first slag purification of a first silicon, separating the slag from the first silicon after finishing the first slag purification, and feeding the separated slag to a second molten silicon in a second purification of the second silicon, wherein purity of said second silicon prior to purification is lower than purity of the first silicon after purification.

Method for producing high purity silicon

A process for producing titanium sponge includes carrying out a reduction reaction by supplying titanium tetrachloride to a reaction vessel which stores a reduction bath liquid containing an upper layer of a reactant bath liquid layer containing fused magnesium as a main component and a lower layer of a product bath liquid layer containing fused magnesium chloride as a main component, wherein the level of the interface between the reactant bath liquid layer and the product bath liquid layer and the level of the reduction bath liquid surface are controlled in response to an accumulated supply of titanium tetrachloride.

Process for producing titanium sponge

A process for producing metallic titanium includes forming metallic titanium fine particles by supplying liquid or mist titanium tetrachloride from above the surface of a reaction bath liquid containing fused magnesium and fused magnesium chloride in a reaction vessel to effect a reaction, wherein a circulating flow perpendicular to the bath surface of the reaction bath liquid is generated or extended just under the bath surface by imparting a stirring force to the reaction bath liquid so as to generate or increase an upward flow rate of the reaction bath liquid in at least part of the region at a depth of more than 100 mm below the bath surface.

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Chiba, Japan

Nobuaki Ito