Preparation of strontium chloride hexahydrate by batch‐cooling crystallization: Control of crystal size and morphology

The effects of initial supersaturation, cooling rate, and stirring rate on the morphology of strontium chloride hexahydrate (SrCl 2 ·6H 2 O) crystals were investigated by batch‐cooling crystallization, providing optimal operating conditions. Uniform needle‐like crystals with a length of 1200.50 μm and a width of 100.92 μm on average were obtained. The corresponding aspect ratio of length to width was about 11.90. Moreover, the morphological modification of SrCl 2 ·6H 2 O crystals using cetyltrimethylammonium chloride (CTAC) was studied. When 20.30 mmol·L −1 of CTAC was added, the length and width of crystals were 792.71 μm and 233.25 μm, respectively, and the corresponding aspect ratio decreased to 3.40. The shape of SrCl 2 ·6H 2 O crystal changed to granule‐like, probably because of the strong interaction of CTAC with the SrCl 2 ·6H 2 O facets with a denser distribution of Cl − ions. This study offers a simple, flexible, and highly efficient approach to regulate the morphology of SrCl 2 ·6H 2 O crystals and opportunities for multiple applications of SrCl 2 ·6H 2 O.