Process for producing pure magnesium oxide

US4944928A · kind A · utility

Assignee

• Veitscher Magnesitwerke-Actien-Gesellschaft · AT

Inventors

• Michael Grill · Overland, US
• Gerhard Graf · Dillingen/Saar, DE

Key dates

• Filing date: Feb 27, 1989
• Grant date: Jul 31, 1990
• Expiry date: Feb 27, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2004/61
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A process for the preparation of pure magnesium oxide, especially suitable for the preparation of refractory products, from magnesium silicate and magnesium hydrosilicate materials such as olivine, serpentine, garnierite, or the like, the starting material being decomposed (digested) with hydrochloric acid, the residues being separated from the decomposition slurry and the sesquioxides to be regarded as contaminants and other contaminants being precipitated from the crude brine thus obtained by the addition of crude serpentine as a pH increasing substance, the precipitates being separated and the magnesium chloride solution thus obtained being subjected to thermal decomposition, particularly by spray calcination, whereby magnesium oxide is obtained and hydrogen chloride is recovered.