Determination of crystallization kinetics from batch experiments II

1983 ◽  
Vol 48 (10) ◽  
pp. 2767-2776 ◽  
Author(s):  
Jaroslav Nývlt ◽  
Stanislav Žáček
Keyword(s):  
Crystal Growth ◽  
Size Distribution ◽  
Crystallization Kinetics ◽  
Kinetic Data ◽  
Batch Experiments ◽  
Aluminium Sulphate ◽  
Batch Crystallization ◽  
Relative Kinetic ◽  
Crystal Product

Relations have been derived for the size distribution of crystal product of batch crystallization with constant and variable supersaturation, applicable where the distribution cannot be approximated by the relation holding for continuous MSMPR crystallizers. In the cases considered, relative kinetic data, but not the kinetic exponents of nucleation and crystal growth, can be evaluated for model experiments involving any variation of supersaturation with time. Application of the relationships is illustrated by treating data for potassium aluminium sulphate precipitation.

Determination of crystallization kinetics from batch experiments

1982 ◽  
Vol 47 (12) ◽  
pp. 3384-3392 ◽  
Author(s):  
Jaroslav Nývlt
Keyword(s):  
Kinetic Data ◽  
Batch Experiments ◽  
Mixed Product ◽  
Batch Crystallization ◽  
Product Removal ◽  
First Case ◽  
Mixed Suspension ◽  
Constant Rate ◽  
Relative Kinetic

Three types of batch crystallization model experiments are considered: a) crystallization in which a constant supersaturation is maintained throughout the experiment (e.g. by programmed cooling); b) crystallization during which supersaturation is produced at a constant rate; c) crystallization (e.g. by precipitation) in which an initial supersaturation produced at the beginning gradually decreases during the run. The kinetic data obtained in the first case are of the same kind as those obtained in a continuous MSMPR (mixed suspension - mixed product removal) crystallizer. The two remaining types of experiment, on the other hand, can only provide relative kinetic data with respect to a reference run.

Calculation of the kinetics of crystallization based on a single batch experiment

1989 ◽  
Vol 54 (12) ◽  
pp. 3187-3197 ◽  
Author(s):  
Jaroslav Nývlt
Keyword(s):  
Crystal Growth ◽  
Size Distribution ◽  
Kinetic Data ◽  
Growth Kinetic ◽  
Crystal Size ◽  
Batch Crystallization ◽  
Crystallization Experiment ◽  
Kinetics Of ◽  
Single Batch ◽  
Kinetics Of Crystal Growth

The kinetics of crystal growth and nucleation in dependence on the supersaturation of a solution of KCL were evaluated based on a single batch crystallization experiment, where the supersaturation was monitored refractometrically and the product crystal size distribution was established at the end of the experiment. The crystal growth kinetic data obtained compare well with published values, for the nucleation data the agreement is less satisfactory.

Scale-up of stirred crystallisers. Batch precipitation of aluminium potassium sulphate

1982 ◽  
Vol 47 (11) ◽  
pp. 3027-3031 ◽  
Author(s):  
Piotr Karpiński ◽  
Stanislav Žáček ◽  
Jaroslav Nývlt ◽  
Jerzy Budz
Keyword(s):  
Size Distribution ◽  
Kinetic Constant ◽  
Scale Up ◽  
Potassium Sulphate ◽  
Aluminium Sulphate ◽  
Mixing Intensity ◽  
Mean Size ◽  
Relative Kinetic ◽  
Series Of Experiments ◽  
The Mean

Aluminium potassium sulphate has been precipitated batchwise by mixing equal volumes of 0.6 mol/l solutions of potassium sulphate and aluminium sulphate with eventual addition of water in advance. The experiments were performed at 20 and 25 °C in the volume 100 to 200 cm3 and in the volume 0.021 m3. From the size distribution of product crystals, the mean size of crystals has been evaluated and calculated the system kinetic constant of crystallization BN. The system constant is different in both series of experiments and can be correlated with the size of the crystallizer or with mixing intensity. Its value and the value of relative kinetic exponent g/n is comparable with the values obtained in experiments with cooling of solutions.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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