Method of recovering sulfur from solid catalysts

US4824656A · kind A · utility

Assignee

• The United States of America, as represented by The Secretary of The Interior · US

Inventors

• David Andrew Rice · Syracuse, US
• Alexander May · Seeheim-Jugenheim, DE

Key dates

• Filing date: Jun 29, 1987
• Grant date: Apr 25, 1989
• Expiry date: Jun 29, 2007

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S502/517
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A method for recovering sulfur from a solid sulfur-containing catalyst is disclosed which comprises contacting the catalyst with liquid anhydrous ammonia in order to leach the sulfur out of the catalyst, and form an ammonia-sulfur solution. The sulfur is recovered by separating the ammonia from the solution, preferably by evaporation. The catalyst used in this method is also rendered suitable for reuse. The principal utility of the invention is in the ultimate conversion of phosphogypsum, produced primarily in the fertilizer industry, into sulfur so that it can be recycled back into the industry.