Nippon Steel Corporation

Nippon Steel Materials Co., Ltd.

Nippon Steel Sumitomo Metal Corporation

Kensuke Okazawa

Masaki Okajima

Shinji Tokumaru

Junichi Nakagawa

Kenji Umetsu

Takehiko Toh

Jiro Kondo

Keisuke Fujisaki

Kenzo Sawada

Nobuaki Ito

Kiyoshi Wajima

Takatsugu Ueyama

Yasushi Okumura

Satoshi Kosugi

Jirou Kondou

A heat transfer coefficient &#x3b1; between a solidified shell () and a mold () sandwiching a mold flux layer (), and a heat transfer coefficient &#x3b2; between a molten steel () and the solidified shell () are found by solving an inverse problem by using data from thermocouples (), and a solidified shell thickness and a solidified shell temperature are estimated (solidified state in mold estimation amounts), and further, solidified state in mold evaluation amounts are obtained. It is determined whether a normal casting state or an abnormal casting state by comparing at least one or more kinds of amounts contained in the solidified state in mold estimation amounts and the solidified state in mold evaluation amounts with allowable limit values which are found based on at least one or more kinds of amounts contained in the solidified state in mold estimation amounts and the solidified state in mold evaluation amounts when the abnormal casting occurred in a past and stored in a data storage part.

Method, apparatus, and program for determining casting state in continuous casting

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

The present invention provides a method for removal of boron from metal silicon inexpensively and extremely efficiently by a simple method, specifically, heating metal silicon containing boron as an impurity to its melting point to 2200&#xb0; C. to place it in a molten state, then adding a solid mainly comprised of silicon dioxide and a solid mainly comprised of one or both of a carbonate of an alkali metal or a hydrate of a carbonate of an alkali metal into said molten silicon so as to form a slag and remove the boron in the silicon.

Method for removing boron from silicon

The present invention provides a method of refining low purity Si by a slag, in particular removing B, which suppresses wear of the reaction vessel due to the slag and produces high purity Si used for solar battery materials etc. at a low cost, comprising adding SiOand an alkali oxide or alkali carbonate as a slag material into molten Si to form a slag during which adding one or more types of materials among materials the same as the reaction vessel material used or ingredients included in the reaction vessel material into the slag so as to remove the impurities in the molten Si.

Method of refining Si

Continuous casting method and apparatus

Growing community of inventors

Futtsu, Japan

Kensuke Okazawa