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Phosphoric acid purification by suspension melt crystallization: Parametric study of the crystallization and sweating steps
Author(s) -
Wang Baoming,
Li Jun,
Qi Yabing,
Jia Xuhong,
Luo Jianhong
Publication year - 2012
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.201200178
Subject(s) - crystallization , phosphoric acid , suspension (topology) , impurity , fraction (chemistry) , materials science , chromatography , chemistry , metallurgy , organic chemistry , mathematics , homotopy , pure mathematics
In order to purify phosphoric acid, the suspension melt crystallization process was studied. The suspension crystallization experiments were carried out with 80, 84 and 88 wt% phosphoric acid melt at the cooling rates of 0.05, 0.1 and 0.2 K/min, respectively. Sweating experiments were executed for various crystals obtained in suspension crystallization step. The purification effects of the sweating parameters including sweating time, initial inclusion amount and initial impurity content were studied. The inclusion fraction increases with the increase in cooling rate. The inclusion fraction of the crystals which were formed with feed concentration of 84 wt% phosphoric acid melt is lowest among the three feed concentrations. Different impurities have different purification performances during sweating. High inclusion amount and low impurity concentration favor the purification of H 3 PO 4 ·0.5H 2 O crystals during sweating.