Recycling of flux material

US6207125A · kind A · utility

Assignee

• SOLVAY FLUOR und DERIVATE GmbH · DE

Inventors

• Ulrich Seseke-Koyro · Vellmar, DE
• Thomas Born · Holle, DE

Key dates

• Filing date: May 25, 1999
• Grant date: Mar 27, 2001
• Expiry date: May 25, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01B7/192
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Flux residues from aluminium soldering fluxes composed of alkali metal metallates, especially fluoroaluminates of the alkali metals, in particular potassium and cesium, can be recycled by adding them to the reaction mixture used for the production of hydrogen fluoride from fluorspar and sulfuric acid or oleum. In this way the fluorine content of the flux residues becomes reusable, and the anhydrite which is produced can advantageously be used for conventional purposes.