Formation of porous crystals by coupling of dissolution and nucleation process in fractional crystallization

Chang Liu; Yuanhui Ji; Yang Bai; Fangqin Cheng; Xiaohua Lu

doi:10.1016/j.fluid.2007.07.052

Formation of porous crystals by coupling of dissolution and nucleation process in fractional crystallization

Chang Liu
, Yuanhui Ji
, Yang Bai
, Fangqin Cheng
, Xiaohua Lu^*

^*Corresponding author for this work

Nanjing University of Technology
Shanxi University

Research output: Contribution to journal › Article › peer-review

13 Citations (Scopus)

Abstract

The fractional crystallization of carnallite (KMgCl₃·6H₂O) in pure water, KCl aqueous solution and MgCl₂ aqueous solution was studied. When carnallite was dissolved in pure water, porous crystals of KCl were formed. However, when the fractional crystallization in KCl or MgCl₂ aqueous solution occured, the solid crystals of KCl with different morphologies were formed. A theoretical model was established to explore this phenomenon. The ionic product of carnallite and KCl with distance far from the surface of carnallite was analyzed in which the activity coefficient of KCl, MgCl₂ and water were calculated with Lu-Maurer model. The dissolution of carnallite, the diffusion of KCl and MgCl₂ in bulk solutions and the nucleation as well as crystal growth of KCl were investigated in detail. It was concluded that the coupling of the high dissolution rate of carnallite and the high nucleation rate of KCl nearby the surface of carnallite resulted in the porous crystals of KCl. TG and SEM analysis shows that high water content in KCl crystals prepared by fractional crystallization of carnallite in water results from the surface porous structure of crystals.

Original language	English
Pages (from-to)	300-305
Number of pages	6
Journal	Fluid Phase Equilibria
Volume	261
Issue number	1-2
DOIs	https://doi.org/10.1016/j.fluid.2007.07.052
Publication status	Published - 1 Dec 2007

Funding

The authors would like to thank Mr. Sebastian Gutmann (University of Oldenburg, Germany) for a review of the manuscript and helpful discussions. This work was supported by the Chinese National Key Technology R&D Program (2006BAB09B00), the National Basic Research Program of China (2003CB615700), the Chinese National Science Foundation for Outstanding Young Scholars (No. 20428606), the Chinese National Natural Science Foundation (Nos. 20376032, 20236010) and the Natural Science of Foundation of Jiangsu Province (BK2004215, BK2002016).

Keywords

Dissolution
Fractional crystallization
Ionic product
Nucleation

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10.1016/j.fluid.2007.07.052

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title = "Formation of porous crystals by coupling of dissolution and nucleation process in fractional crystallization",

abstract = "The fractional crystallization of carnallite (KMgCl3·6H2O) in pure water, KCl aqueous solution and MgCl2 aqueous solution was studied. When carnallite was dissolved in pure water, porous crystals of KCl were formed. However, when the fractional crystallization in KCl or MgCl2 aqueous solution occured, the solid crystals of KCl with different morphologies were formed. A theoretical model was established to explore this phenomenon. The ionic product of carnallite and KCl with distance far from the surface of carnallite was analyzed in which the activity coefficient of KCl, MgCl2 and water were calculated with Lu-Maurer model. The dissolution of carnallite, the diffusion of KCl and MgCl2 in bulk solutions and the nucleation as well as crystal growth of KCl were investigated in detail. It was concluded that the coupling of the high dissolution rate of carnallite and the high nucleation rate of KCl nearby the surface of carnallite resulted in the porous crystals of KCl. TG and SEM analysis shows that high water content in KCl crystals prepared by fractional crystallization of carnallite in water results from the surface porous structure of crystals.",

keywords = "Dissolution, Fractional crystallization, Ionic product, Nucleation",

author = "Chang Liu and Yuanhui Ji and Yang Bai and Fangqin Cheng and Xiaohua Lu",

year = "2007",

month = dec,

day = "1",

doi = "10.1016/j.fluid.2007.07.052",

language = "English",

volume = "261",

pages = "300--305",

journal = "Fluid Phase Equilibria",

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TY - JOUR

T1 - Formation of porous crystals by coupling of dissolution and nucleation process in fractional crystallization

AU - Liu, Chang

AU - Ji, Yuanhui

AU - Bai, Yang

AU - Cheng, Fangqin

AU - Lu, Xiaohua

PY - 2007/12/1

Y1 - 2007/12/1

N2 - The fractional crystallization of carnallite (KMgCl3·6H2O) in pure water, KCl aqueous solution and MgCl2 aqueous solution was studied. When carnallite was dissolved in pure water, porous crystals of KCl were formed. However, when the fractional crystallization in KCl or MgCl2 aqueous solution occured, the solid crystals of KCl with different morphologies were formed. A theoretical model was established to explore this phenomenon. The ionic product of carnallite and KCl with distance far from the surface of carnallite was analyzed in which the activity coefficient of KCl, MgCl2 and water were calculated with Lu-Maurer model. The dissolution of carnallite, the diffusion of KCl and MgCl2 in bulk solutions and the nucleation as well as crystal growth of KCl were investigated in detail. It was concluded that the coupling of the high dissolution rate of carnallite and the high nucleation rate of KCl nearby the surface of carnallite resulted in the porous crystals of KCl. TG and SEM analysis shows that high water content in KCl crystals prepared by fractional crystallization of carnallite in water results from the surface porous structure of crystals.

AB - The fractional crystallization of carnallite (KMgCl3·6H2O) in pure water, KCl aqueous solution and MgCl2 aqueous solution was studied. When carnallite was dissolved in pure water, porous crystals of KCl were formed. However, when the fractional crystallization in KCl or MgCl2 aqueous solution occured, the solid crystals of KCl with different morphologies were formed. A theoretical model was established to explore this phenomenon. The ionic product of carnallite and KCl with distance far from the surface of carnallite was analyzed in which the activity coefficient of KCl, MgCl2 and water were calculated with Lu-Maurer model. The dissolution of carnallite, the diffusion of KCl and MgCl2 in bulk solutions and the nucleation as well as crystal growth of KCl were investigated in detail. It was concluded that the coupling of the high dissolution rate of carnallite and the high nucleation rate of KCl nearby the surface of carnallite resulted in the porous crystals of KCl. TG and SEM analysis shows that high water content in KCl crystals prepared by fractional crystallization of carnallite in water results from the surface porous structure of crystals.

KW - Dissolution

KW - Fractional crystallization

KW - Ionic product

KW - Nucleation

UR - https://www.scopus.com/pages/publications/35348912434

UR - https://www.sciencedirect.com/science/article/pii/S0378381207004463?via%3Dihub

U2 - 10.1016/j.fluid.2007.07.052

DO - 10.1016/j.fluid.2007.07.052

M3 - Article

AN - SCOPUS:35348912434

SN - 0378-3812

VL - 261

SP - 300

EP - 305

JO - Fluid Phase Equilibria

JF - Fluid Phase Equilibria

IS - 1-2

ER -

Formation of porous crystals by coupling of dissolution and nucleation process in fractional crystallization

Abstract

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Keywords

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