Method for producing ammonium paratungstate hydrates and ammonium paratungstate decahydrate

US8216533B2 · kind B2 · utility

Assignee

• H.C. STARCK INC. · US

Inventors

• Viktor Stoller · Bad Harzburg, DE
• Michael Erb · Salzgitter, DE
• Juliane Meese-Marktscheffel · Goslar, DE
• Michael Lohse · Goslar, DE
• Klaus-Jürgen Marschall · Goslar, DE
• Frank Schrumpf · Goslar, DE

Key dates

• Filing date: Jan 29, 2008
• Grant date: Jul 10, 2012
• Expiry date: Apr 22, 2028

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/2982
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The invention is directed to a process for the continuous preparation of ammonium paratungstate hydrate by back reextraction of a tungsten-laden organic phase with an ammonia-containing aqueous solution in a mixer-settler apparatus. The reextraction is carried out at an NH3:W molar ratio of from 0.83 to 1.30, and a volume feed ratio of the tungsten-laden organic phase to the ammonia-containing aqueous solution of from 5 to 25. The above crystalline is in high purity and in high yield. The production method can be carried out in a simple and energy-efficient manner.