PROCESS FOR THE PRODUCTION OF A LOW SODA CONTENT SMELTING GRADE ALUMINA

摘要

A process for the production of a low soda-content smelting grade alumina from alumina trihydrate, wherein the process comprises the steps of: (a) calcining alumina trihydrate at a temperature between 700.degree.C and 1200.degree.C to produce alumina; (b) leaching the alumina in an aqueous slurry to which carbon dioxide is added, the leaching occurring at a temperature less than 80.degree.C; (c) washing the leached alumina slurry and separating the washed alumina therefrom; and (d) heating the washed alumina slurry at a temperature between 300.degree.C and 1100.degree.C to produce a smelting grade alumina with a low soda content.