화학공학소재연구정보센터
홈 로그인 로그아웃 연락처 사이트맵
Korean Journal of Chemical Engineering, Vol.17, No.6, 643-648, November, 2000
DOI10.1007/BF02699111  Export Citation
Crystallization of High Purity Ammonium Meta-Tungstate for Production of Ultrapure Tungsten Metal
Cheong-Song Choi†, Jun-Hyung Kim1, and Choul-Ho Lee2
  • Dept. of Chemical Engineering, Sogang University, .P.O Box 1142, Seoul, Korea
  • 1Agency for Defense Development, Taejon 305-600, Korea
  • 2Dept. of Chemical Engineering, Kongju National University, Kongju 314-701, Korea
E-mail:
The growth mechanism of Ammonium Meta-Tungstate (AMT) crystal was interpreted as two-step model. Growth rates of AMT crystals were measured in a fluidized bed crystallizer. The effects of temperature, supersaturation and crystal size on the crystal growth were investigated. The contribution of the diffusion step increased with the increase of temperature, crystal size and supersaturation. The nucleation kinetics from measurements on the width of the metastable region of Ammonium Meta-Tungstate (AMT) was also evaluated. The crystal size distribution from a programmed cooling crystallization system was predicted by the numerical simulation of a mathematical model using the kinetics of nucleation and crystal growth. It was also observed that the shape of AMT crystals was changed during the growth period.
Keywords:Ammonium Meta-Tungstate;Crystallization;Process Control;Crystal Growth;Crystal Size Distribution
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