Process for separating off calcium nitrate tetrahydrate by crystallization.

摘要

Separating Ca(NO<Sub>3</Sub>)<Sub>2</Sub>.4H<Sub>2</Sub>O from a nitrophosphate digestion liquor by crystallization, wherein Ca(N0<Sub>3</Sub>)<Sub>2</Sub>.4H<Sub>2</Sub>0 seeding material with a particle size smaller than 100 µm is added to this liquor at a temperature of 0,1-2°C lower than the saturation temperature, the resulting liquor is batchwise cooled, and the Ca(NO<Sub>3</Sub>)<Sub>2</Sub>.4H<Sub>2</Sub>O crystallized out is separated from the cooled liquor.

The Ca(NO<Sub>3</Sub>)<Sub>2</Sub>.4H<Sub>2</Sub>O is substantially crystallized out without excessive cooling as very coarse and uniform particles which can be easily separated out.