Growth and aggregation rates for calcite and calcium oxalate monohydrate

✍ Scribed by Alan P. Collier; Michael J. Hounslow

• Publisher: American Institute of Chemical Engineers
• Year: 1999
• Tongue: English
• Weight: 114 KB
• Volume: 45
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.690451105

✦ Synopsis

Seeded batch experiments were conducted at low magma densities and moderate ionic strength to determine the growth and aggregation rate constants for calcite precipitation in a stirred ®essel. The growth was found to be surface-reaction-limited, and the growth rates agreed broadly with other studies of calcite precipitation. Aggregation rates ha®e rarely been presented for calcite. The aggregation rate constant studied here was directly proportional to the instantaneous growth rate and in®ersely proportional to the a®erage shear rate in the ®essel. The results were also compared with similar work carried out on calcium oxalate monohydrate. It was found that the relationship between the aggregation rate constant and stirrer speed was ®irtually identical in the two cases, despite almost an order of magnitude difference in the growth rate constants.