US 12,391,571 B2
Method for preparing ammonium metatungstate
Julia Meese-Marktscheffel, Goslar (DE); Armin Olbrich, Seesen (DE); Anja Weiland, Langelsheim (DE); Frank Van Der Pütten, Goslar (DE); Tino Säuberlich, Bad Harzburg (DE); Tobias Schröer, Bad Harzburg (DE); and Jürgen Müller, Pforzheim (DE)
Assigned to H.C. Starck Tungsten GmbH, Munich (DE)
Appl. No. 17/311,432
Filed by H.C. Starck Tungsten GmbH, Munich (DE)
PCT Filed Dec. 18, 2019, PCT No. PCT/EP2019/086077
§ 371(c)(1), (2) Date Jun. 7, 2021,
PCT Pub. No. WO2020/127571, PCT Pub. Date Jun. 25, 2020.
Claims priority of application No. 18213826 (EP), filed on Dec. 19, 2018.
Prior Publication US 2021/0340023 A1, Nov. 4, 2021
Int. Cl. C01G 41/00 (2006.01); B01D 61/02 (2006.01); B01D 63/10 (2006.01); C02F 1/44 (2023.01); C02F 101/20 (2006.01)
CPC C01G 41/006 (2013.01) [B01D 61/025 (2013.01); B01D 61/026 (2022.08); B01D 63/10 (2013.01); C02F 1/441 (2013.01); C02F 2101/20 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A process for preparing ammonium metatungstate (AMT), characterized in that an aqueous ammonium metatungstate solution (A) is concentrated by passing the aqueous ammonium metatungstate solution (A) through at least one high-pressure reverse osmosis cell to obtain a concentrate (C) containing AMT and a permeate (P), characterized in that said at least one reverse osmosis is performed under a pressure of more than 50 bar.