Abstract: A high-strength ?-alumina formed body with a low soda content, of which pore distribution is controlled, can be provided in an easy and inexpensive manner. The ?-alumina formed body can be produced by a method comprising calcining a gibbsite-phase aluminum hydroxide to obtain rehydratable alumina powder; forming the rehydratable alumina powder in the presence of water to obtain a formed body; maintaining the formed body in the presence of water at about 110-200° C., to rehydrate the formed body; and calcining the rehydrated formed body at about 1200° C. or higher. The ?-alumina formed body is useful as a carrier for catalysts, chemicals, microbes for food leftover disposal and the like.

Abstract: A spherical porous ceramic body and the production method thereof are provided. As to the porous ceramic body, the total volume of the pores having a pore radius of from 1.8 nm to 100 ?m is about 0.25 cm3/g or more, the mode of pore radius of the pores is from about 1 ?m to about 6 ?m and the packing density is from about 0.7 g/cm3 to about 1 g/cm3. The porous ceramic body is suitably used as a carrier for a catalyst and has high mechanical strength.

Abstract: An activated alumina formed body with a high bulk density and a large macro-pore volume is provided. The activated alumina formed body can be produced by a method comprising the steps of calcining a gibbsite-phase aluminum hydroxide having a median particle size of from about 10 ?m to about 35 ?m and a packed bulk density of from about 1.05 g/cm3 to about 1.3 g/cm3 to obtain an at least partially rehydratable alumina powder; forming the rehydratable alumina powder in the presence of water; maintaining the formed body in the presence of water to rehydrate the formed body; and calcining the rehydrated formed body to obtain an activated alumina formed body. The activated alumina formed body is usable as an adsorbent, a catalyst supporting precious metal or the like.

Abstract: An activated alumina formed body with a high bulk density and a large macro-pore volume is provided. The activated alumina formed body can be produced by a method comprising the steps of calcining a gibbsite-phase aluminum hydroxide having a median particle size of from about 10 ?m to about 35 ?m and a packed bulk density of from about 1.05 g/cm3 to about 1.3 g/cm3 to obtain an at least partially rehydratable alumina powder; forming the rehydratable alumina powder in the presence of water; maintaining the formed body in the presence of water to rehydrate the formed body; and calcining the rehydrated formed body to obtain an activated alumina formed body. The activated alumina formed body is usable as an adsorbent, a catalyst supporting precious metal or the like.

Abstract: A high-strength ?-alumina formed body with a low soda content, of which pore distribution is controlled, can be provided in an easy and inexpensive manner. The ?-alumina formed body can be produced by a method comprising calcining a gibbsite-phase aluminum hydroxide to obtain rehydratable alumina powder; forming the rehydratable alumina powder in the presence of water to obtain a formed body; maintaining the formed body in the presence of water at about 110-200° C., to rehydrate the formed body; and calcining the rehydrated formed body at about 1200° C. or higher. The ?-alumina formed body is useful as a carrier for catalysts, chemicals, microbes for food leftover disposal and the like.

Abstract: A high-strength &agr;-alumina formed body with a low soda content, of which pore distribution is controlled, can be provided in an easy and inexpensive manner. The &agr;-alumina formed body can be produced by a method comprising calcining a gibbsite-phase aluminum hydroxide to obtain rehydratable alumina powder; forming the rehydratable alumina powder in the presence of water to obtain a formed body; maintaining the formed body in the presence of water at about 110-200 ° C., to rehydrate the formed body; and calcining the rehydrated formed body at about 1200° C. or higher. The &agr;-alumina formed body is useful as a carrier for catalysts, chemicals, microbes for food leftover disposal and the like.

Abstract: An activated alumina formed body with a high bulk density and a large macro-pore volume is provided. The activated alumina formed body can be produced by a method comprising the steps of calcining a gibbsite-phase aluminum hydroxide having a median particle size of from about 10 &mgr;m to about 35 &mgr;m and a packed bulk density of from about 1.05 g/cm3 to about 1.3 g/cm3 to obtain an at least partially rehydratable alumina powder; forming the rehydratable alumina powder in the presence of water; maintaining the formed body in the presence of water to rehydrate the formed body; and calcining the rehydrated formed body to obtain an activated alumina formed body. The activated alumina formed body is usable as an adsorbent, a catalyst supporting precious metal or the like.

Abstract: A spherical porous ceramic body and the production method thereof are provided. As to the porous ceramic body, the total volume of the pores having a pore radius of from 1.8 nm to 100 &mgr;m is about 0.25 cm3/g or more, the mode of pore radius of the pores is from about 1 &mgr;m to about 6 &mgr;m and the packing density is from about 0.7 g/cm3 to about 1 g/cm3. The porous ceramic body is suitably used as a carrier for a catalyst and has high mechanical strength.