Director-general of Agency of Industrial Science and Technology

Toshiba Ceramics Co., Ltd.

Akira Sano

Isao Imai

Kouichi Sueyoshi

Masaaki Mori

Yushi Horiuchi

Toshitsuga Ishii

Yoshihiro Okumura

A mixture of silica powder and carbon powder is heated in a mixture of NH.sub.3 gas and C.sub.m H.sub.n gas. Only silica powder may be heated in a mixture of NH.sub.3 gas and C.sub.m H.sub.n gas.

Method for making silicon nitride powder

A batch-operated furnace apparatus for manufacturing powdered silicon nitride comprises a reaction furnace having a reaction chamber, an upper portion, a bottom portion and a side portion, a feed pipe placed at the upper portion of the reaction furnace for feeding starting materials in a fine or coarse particle form, an exhaust pipe placed at the upper portion of the reaction furnace for removing gasses from the reaction chamber, a gas distributor plate positioned at the bottom portion of the reaction chamber for introducing nitrogen gas into the reaction chamber so as to form a fluidized bed at the bottom portion of the reaction chamber, a heater for heating the starting materials of the fluidized bed within the reaction chamber, a discharge port formed in the gas distributor plate, a discharge pipe joined to the discharge port of the gas distributor plate, a valve seat formed at the discharge port, a discharge valve means having the valve which engages the valve seat of the discharge port, and a guide tube provided at an upper portion of the reaction furnace. The discharge valve means extends through the guide tube in a vertical direction in such a way that the valve of the discharge valve means selectively contacts the valve seat of the discharge port thereby to open or close the discharge port.

Apparatus for manufacturing powdered silicon nitride

Growing community of inventors

Kariya, Japan

Akira Sano