Provided is a method for manufacturing a spherical particle material in which the particle size distribution is easily controlled. This method has: a granulation step of granulating a raw particle material formed of an inorganic material having a D50 of not larger than 5 μm to form a granulated body; and a spherizing step of heating and melting the granulated body to form the spherical particle material having a D50 larger than a D50 of the raw particle material. A melting method is used as a basic method for manufacturing the spherical particle material having a necessary particle size distribution. The granulated body is used to manufacture the spherical particle material having the necessary particle size distribution by the melting method.

Provided is a method for manufacturing a spherical particle material in which the particle size distribution is easily controlled. This method has: a granulation step of granulating a raw particle material formed of an inorganic material having a D50 of not larger than 5 μm to form a granulated body; and a spherizing step of heating and melting the granulated body to form the spherical particle material having a D50 larger than a D50 of the raw particle material. A melting method is used as a basic method for manufacturing the spherical particle material having a necessary particle size distribution. The granulated body is used to manufacture the spherical particle material having the necessary particle size distribution by the melting method.

A method of making an alumina including providing an alumina slurry, aging the slurry, adding a tricarboxylic acid to the aged alumina slurry, further aging the slurry, and spray drying, the method being characterized by the addition of a dicarboxylic acid either at the same time as the tricarboxylic acid, or after the second aging and before the spray drying. The resulting alumina is dispersible at a pH greater than 9.5 above 95% and has a viscosity below 0.4 Pa.Math.S for 10 wt % sols.

A method of making an alumina including providing an alumina slurry, aging the slurry, adding a tricarboxylic acid to the aged alumina slurry, further aging the slurry, and spray drying, the method being characterized by the addition of a dicarboxylic acid either at the same time as the tricarboxylic acid, or after the second aging and before the spray drying. The resulting alumina is dispersible at a pH greater than 9.5 above 95% and has a viscosity below 0.4 Pa.Math.S for 10 wt % sols.

The present invention relates to a calcined shaped alumina and to a method of preparing a calcined shaped alumina. The method comprises that the alumina in the alumina suspension is hydrothermally aged to have a specific crystallite size. This in turn produces a highly stable alumina in the form of a calcined shaped alumina particularly at temperatures of 1200° C. and above.

The present invention relates to a calcined shaped alumina and to a method of preparing a calcined shaped alumina. The method comprises that the alumina in the alumina suspension is hydrothermally aged to have a specific crystallite size. This in turn produces a highly stable alumina in the form of a calcined shaped alumina particularly at temperatures of 1200° C. and above.

A method of making an alumina including providing an alumina slurry, aging the slurry, adding a tricarboxylic acid to the aged alumina slurry, further aging the slurry, and spray drying, the method being characterized by the addition of a dicarboxylic acid either at the same time as the tricarboxylic acid, or after the second aging and before the spray drying. The resulting alumina is dispersible at a pH greater than 9.5 above 95% and has a viscosity below 0.4 Pa.S for 10 wt% sols.

A method of making an alumina including providing an alumina slurry, aging the slurry, adding a tricarboxylic acid to the aged alumina slurry, further aging the slurry, and spray drying, the method being characterized by the addition of a dicarboxylic acid either at the same time as the tricarboxylic acid, or after the second aging and before the spray drying. The resulting alumina is dispersible at a pH greater than 9.5 above 95% and has a viscosity below 0.4 Pa.S for 10 wt% sols.

An alumina powder satisfying the following expressions is provided: (Expression 1) 0.7T.sub.X≤T.sub.A≤1.3T.sub.X; (Expression 2) 0.7T.sub.X≤T.sub.B≤1.3T.sub.X; and (Expression 3) 0.7T.sub.X≤T.sub.C≤1.3T.sub.X, where T.sub.X represents a mean value of a peak height T.sub.A of a peak A in a particle size distribution of 0.3 μm or more to less than 1.2 μm, a peak height T.sub.B of a peak B in a particle size distribution of 0.7 μm or more to less than 3 μm, and a peak height T.sub.C of a peak C in a particle size distribution of 3 μm or more to less than 20 μm.

An alumina powder satisfying the following expressions is provided: (Expression 1) 0.7T.sub.X≤T.sub.A≤1.3T.sub.X; (Expression 2) 0.7T.sub.X≤T.sub.B≤1.3T.sub.X; and (Expression 3) 0.7T.sub.X≤T.sub.C≤1.3T.sub.X, where T.sub.X represents a mean value of a peak height T.sub.A of a peak A in a particle size distribution of 0.3 μm or more to less than 1.2 μm, a peak height T.sub.B of a peak B in a particle size distribution of 0.7 μm or more to less than 3 μm, and a peak height T.sub.C of a peak C in a particle size distribution of 3 μm or more to less than 20 μm.