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:
Apr. 24, 2001
Filed:
Mar. 08, 1999
John S. Rendall, Albuquerque, NM (US);
Other;
Abstract
The smelting of aluminum from alumina in the Hall-Heroult process can be dramatically improved by lowering power consumption and in the use of carbon free anodes by using a feed of positively charged alumina. Laboratory experiments have shown that the apparent solubility and reactivity of alumina in molten fluoride baths is surprisingly increased by altering the negatively charged aluminum hydroxide Al(OH),particles, at about pH of nine, to positively charged particles containing Al,with a pH of less than two, by using acid solutions. The alumina thus produced is referred to as Al,alumina, or positively charged alumina. In particular, sulfuric acid is used to convert aluminum hydroxide using the Bayer process to a family of basic aluminum sulfates, 3Al,O,.4SO,.9H,O, which are dehydrated and calcined to produce Al,alumina.