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Semi‐Batch Precipitation of Calcium Oxalate Monohydrate
Author(s) -
Millan A.,
Grases F.,
Söhnel O.,
Křivánková I.
Publication year - 1992
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.2170270105
Subject(s) - agglomerate , supersaturation , economies of agglomeration , precipitation , stoichiometry , crystal growth , particle size , particle size distribution , chemical engineering , crystallography , oxalate , mineralogy , chemistry , materials science , inorganic chemistry , organic chemistry , meteorology , physics , engineering
Calcium oxalate monohydrate (COM) formation on the semi‐batch precipitation of CaCl 2 and Na 2 C 2 O 4 solutions in the stoichiometric ratio carried out at pH = 6 and 37 or 70°C, respectively, was studied. When a certain level of supersaturation in the system is reached, individual COM crystals of a rather uniform size are formed. These crystals then grown and form ‘loose’ agglomerates that later develop into compact and spherical particles. The particle size distribution (PSD) rapidly shifts during early stages of precipitation towards larger sizes as a result of crystal growth and agglomeration. Later the PSD reaches a shape and position on the size axis that remain virtually constant with progressing precipitation. COM agglomerates consisting of mainly intergrown crystals are formed by mechanism of primary and secondary agglomeration. The primary agglomeration can constitute an important factor in urolithiasis.