The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 06, 1978
Filed:
May. 27, 1977
Kent W Loest, Broomfield, CO (US);
George H Kesler, Evergreen, CO (US);
Southwire Company, Carrollton, GA (US);
National Steel Corporation, Pittsburgh, PA (US);
Earth Sciences, Inc., Golden, CO (US);
Abstract
The invention is an improvement in the method for recovering aluminum values from alunite ore by roasting the ore to remove water, reducing the ore by roasting it in a reducing atmosphere to remove sulfate, optionally roasting the reduced ore in an oxidizing atmosphere to convert any sulfides formed in the second roast to oxides, leaching the calcined ore with water as a solvent to remove compounds of sulfur and alkali metals, recovering aluminum values as soluble aluminates from the residue from the leaching step by digesting it with at least one alkali metal hydroxide, removing contaminate silica from the resulting leach solution, and precipitating aluminum hydroxide from the solution, the improvement being the use of a two stage reduction of the dehydrated alunite ore, in which the ore is reduced by sulfur in the first stage, followed by a second stage reduction with another reducing agent such as hydrogen.