This paper pertains to the evaporation crystallization of sodium tungstate crystals from tungsten containing alkaline solutions. Crystallization experiments were performed in a 1L glass reactor by about 80% evaporation of sodium tungstate-sodium hydroxide solutions from their original volume. All experiments were performed in the presence of magnesium hydroxide or calcium hydroxide seeds with the aim to obtain large-size sodium tungstate crystals. Sodium tungstate crystals after crystallization were separated from mother liquor by filtration and were dried at 110 �C. Characterization of sodium tungstate crystals was carried out by scanning electron microscopy, particles size distribution and chemical analysis after dissolving the crystals in water. The work was performed using a �design-of-experiment� approach.  The effect of three parameters i.e. seeding compound type, seed amount and volume of sodium tungstate-sodium hydroxide solutions where seeds were introduced was studied on the size of sodium tungstate crystals.  Data was processed using the software Design-Expert version 8.0.1.

Seeded crystallization of sodium tungstate crystals from sodium tungstate-sodium hydroxide solutions

244th National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.