Continuous Reaction Crystallization of Struvite in a DTM Type Crystallizer With Jet Pump of Ascending Suspension Flow in a Mixing Chamber–Kinetic Approach of the Process

• 作者: Agata Mazienczuk Andrzej Matynia Boguslawa Wierzbowska Krzysztof Piotrowski
• 来源期刊: 结晶过程及技术期刊(英文)
• 学科: 化学
• 关键词: STRUVITE Crystal Size Distribution (CSD) Reaction Crystallization Kinetics CONTINUOUS DTM TYPE CRYSTALLIZER Jet Pump
• 年，卷（期）: 2012,（3）
• 页码范围: 96-104
• 页数: 9页
• 分类号: O6

摘要

Reaction crystallization of struvite in water solutions containing 0.20 mass % of phosphate(V) ions by magnesium and ammonium ions addition was investigated experimentally. Process was carried out in DTM type crystallizer with liquid jet pump device in 298 K assuming stoichiometric conditions. Struvite crystals of mean size Lm 5.2-23.0 μm were produced depending on pH (9-11) and mean residence time of suspension in a crystallizer τ (900-3600 s). Under these conditions linear growth rate of struvite crystals (SIG MSMPR kinetic model) decreased 2-time with the increase in pH and 3-time with the elongation of mean residence time of crystal suspension from 7.11×10-9 m/s (pH 9, τ900 s) to 1.65×10-9 m/s (pH 11, τ3600 s). Nucleation rate varied within the 7.9×108-1.8×1010 1/(sm3) limits. Struvite product of maximal linear size exceeded 100 μm with 10 vol. % of < 3 μm fraction corresponded to pH 9 and τ3600 s.