Model to Simulate the Structure of a Crystal Pillar and Optimize the Separation Efficiency in Melt Crystallization by Fractal Theory and Technique

• Published in: Industrial & engineering chemistry research 2011-09, Vol.50 (17), p.10229-10245
• Main Authors: Jiang, Xiaobin, Hou, Baohong, Wang, Jingkang, Yin, Qiuxiang, Zhang, Meijing
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical engineering; Computer simulation; Crystal structure; Crystallization; Exact sciences and technology; Fractal analysis; Mathematical models; Melts (crystal growth); Pillars; Separation; Separations
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie200810v

In this paper, an existing fractal porous media model was applied to simulate the structure of the crystal pillar formed in melt crystallization for electronic grade phosphoric acid (EGPA) preparation. The model was modified to meet the crystallization process; the structure parameter of the crystal pillar could be obtained by inspecting the seeping process and measuring the solid–liquid phase equilibrium condition. A characterized factor φ with realistic significance was introduced to modify the model, too. The simulation results met the experiment data well. An optimized operation curve was developed to obtain ultrapure EGPA product with higher separation efficiency. An optimized operation was proposed in this paper. Simulating the optimized operation with the model established above, we still obtained a satisfactory result. So the optimized experiment verified the stability and reliability of this model. This model can evaluate the separation effect which is vital to industrial crystal product manufacturing by anticipating the effective porosity of a crystal pillar.