The invention describes methods for the production of a high purity aluminum salt solution via electrodialysis, and ultimately, the conversion of the high purity aluminum salt to high purity aluminum oxide.

The invention describes methods for the production of a high purity aluminum salt solution via electrodialysis, and ultimately, the conversion of the high purity aluminum salt to high purity aluminum oxide.

The present invention aims to provide a simple and efficient method for manufacturing -alumina particles, main component particles of which each have a crystal face other than the face [001] as a main crystal face and a polyhedral shape other than a hexagonal bipyramidal shape. According to the method for manufacturing -alumina particles of the present invention, when an aluminum compound is calcined in the presence of a specific content of a metal compound, -alumina particles each having a particle diameter of 50 m or less, a degree of crystallization of 90% or more, and a polyhedral shape can be obtained.

The present invention aims to provide a simple and efficient method for manufacturing -alumina particles, main component particles of which each have a crystal face other than the face [001] as a main crystal face and a polyhedral shape other than a hexagonal bipyramidal shape. According to the method for manufacturing -alumina particles of the present invention, when an aluminum compound is calcined in the presence of a specific content of a metal compound, -alumina particles each having a particle diameter of 50 m or less, a degree of crystallization of 90% or more, and a polyhedral shape can be obtained.