Mino Ceramic Co., Ltd.

Mino Yogyo Co., Ltd.

Toru Honda

Takeshi Kumazawa

Fumikazu Tanemura

Yoshiharu Kajita

Yoshiyuki Sensui

Katsuhiko Kato

Keisuke Sakakibara

An aspect of the present invention is to provide an economical production technology for obtaining a dense boron carbide ceramic product without impairment to excellent mechanical properties, which boron carbide ceramics are inherently equipped with, by conducting heating under normal pressure without application of pressure and without needing addition of a large amount of a sintering additive to a raw material or needing any special additive or treatment. The present invention provides a production process in which, upon heating a boron carbide green body under normal pressure without application of pressure after pressing a boron carbide powder material to obtain the boron carbide green body, the boron carbide green body is heated with one of a powder, green body or sintered body, which contains at least one of aluminum and silicon, being disposed in a furnace.

Dense boron carbide ceramic and process for producing the same

A novel basic refractory composition is disclosed. This composition has high resistance to calcium silicates such as cement clinkers and slag formed in steelmaking operations. It also has superior resistance to thermal shock and stresses such as load in high temperature. A refractory brick produced from this composition can be used in the firing zone of a rotary kiln and successfully withstands cement firing operations for a significantly longer period than conventional refractory bricks. The basic refractory composition consists of a synthetic calcium zirconate based clinker in combination with raw materials for magnesia; the molar ratio of CaO to ZrO.sub.2 in said clinker is in the range of 0.5-1.1, at least part of said clinker being in the form of particles having a size not smaller than 0.5 mm, ZrO.sub.2 being present in an amount of 4-49 wt % of said composition, the sum of CaO and MgO being 50-95 wt %, and the sum of ZrO.sub.2, CaO and MgO being at least 80 wt %.

Basic refractory composition

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Aichi, Japan

Toru Honda