The composite particles contain alumina particles with a card-house structure formed of three or more plate-like alumina particles that adhere to each other and an inorganic covering portion located on a surface of the plate-like alumina particles and containing a composite metal oxide.

The present invention relates to a porous aluminum hydrate, to a process for preparing same and to the use of same as intermediate in the preparation of an alumina or of a mixed oxide based on aluminum, on cerium and on zirconium. The invention also relates to the alumina obtained from the aluminum hydrate.

The present invention relates to a porous aluminum hydrate, to a process for preparing same and to the use of same as intermediate in the preparation of an alumina or of a mixed oxide based on aluminum, on cerium and on zirconium. The invention also relates to the alumina obtained from the aluminum hydrate.

Alpha-Alumina flakes having a particle thickness of 130-400 nm, a D.sub.50-value of 15-30 m, a D.sub.90-value of 30-45 m and a D.sub.10-value of <9.5 m. Use of the alumina flakes in varnishes, paints, automotive coatings printing inks, masterbatches, plastics and cosmetic formulations. Also, use of the alumina flakes as a substrate for effect pigments and in organic dyes.

Alpha-Alumina flakes having a particle thickness of 130-400 nm, a D.sub.50-value of 15-30 m, a D.sub.90-value of 30-45 m and a D.sub.10-value of <9.5 m. Use of the alumina flakes in varnishes, paints, automotive coatings printing inks, masterbatches, plastics and cosmetic formulations. Also, use of the alumina flakes as a substrate for effect pigments and in organic dyes.

Alpha-Alumina flakes having a particle thickness of 130-400 nm, a D.sub.50-value of 15-30 m, a D.sub.90-value of 30-45 m and a D.sub.10-value of <9.5 m. Use of the alumina flakes in varnishes, paints, automotive coatings printing inks, masterbatches, plastics and cosmetic formulations. Also, use of the alumina flakes as a substrate for effect pigments and in organic dyes.

Alpha-Alumina flakes having a particle thickness of 130-400 nm, a D.sub.50-value of 15-30 m, a D.sub.90-value of 30-45 m and a D.sub.10-value of <9.5 m. Use of the alumina flakes in varnishes, paints, automotive coatings printing inks, masterbatches, plastics and cosmetic formulations. Also, use of the alumina flakes as a substrate for effect pigments and in organic dyes.

The invention provides highly reactive nano-sized alumina particle compositions, including alumina compositions with a BET surface areas on the order of 2000 m.sup.2/g. Also disclosed are impregnated alumina supports comprising materials that are metal oxides or carbonates. Methods for the synthesis and fabrication of these compositions are provided, along methods for the use of these compositions as sorbents.

The present invention relates to an alpha alumina having a high purity, a high density and a low surface area and particularly, to a method to produce such an alpha alumina as well as to the use of the alpha alumina in sapphire production or the production of composite and ceramic bodies.

The present invention relates to an alpha alumina having a high purity, a high density and a low surface area and particularly, to a method to produce such an alpha alumina as well as to the use of the alpha alumina in sapphire production or the production of composite and ceramic bodies.