ri = components of R; i is the number of 13C atoms in the
t = index xi = Components Of x; i represents the ~ t d x r of deuterium Functions L ( i , j ) = the larger of i or j
Ind. Eng. Chem. Res. 1989, 28, 844-850
Literature Cited Dibeler, V. H.; Mohler, F. L.; de Hemptinne, M. Mass Spectra of the
Deuteroethylenes. J . Res. Natl. Bur. Stand. 1954, 53(2), 107. Koski, W. S.; Kaufman, J. J.; Friedman, L.; Irsa, A. P. Mass Spec-
trometric Study of the B,D8-B5H9 Exchange Reaction. J. Chem.
Lenz, D. H.; Conner, Wm. C. Computer Analysis of the Cracking Patterns of Deuterated Hydrocarbons. Anal. Chim. Acta 1985,
Ozaki, A. Isotopic Studies of Heterogeneous Catalysis; Kodonsha
atoms in the molecule Phys. 1956, 24(2), 221-225.
S(i , j ) = the smaller of i or j 173, 227-238.
Ltd./Academic Press: New York, 1977.
raffin Hydrocarbons on Electron Impact: Synthesis and Mass Spectra of some Deuterated Paraffin Hydrocarbons. Discuss. Faraday SOC. 1951, 10, 46.
Registry No. D,, 7782-39-0; benzene-d,, 1120-89-4; benzene-d,,
benzene-d5, 13657-09-5; benzene-d6, 1076-43-3; hexane, 110-54-3; hexane-d,, 98821-94-4; hexane-d,, 98821-93-3; hexane-da, 98821- 92-2; hexane-d,, 120295-95-6; hexane-d,, 120311-04-8; hexane-d6, 120295-96-7: hexane-d,. 120295-97-8: hexane-dn. 120295-98-9:
25323-71-1; benzene-4, 25321-35-1; 25321-36-2; Schissler, D, 0.; Thompson, S. 0.; Turkevich, J. Behaviour of pa-
hexane-d9, 120295-99-01 hexane-d,,, ' 120296-0016; hexane-d,,; 120296-01-7; hexane-d,,, 120296-02-8; hexane-d,,, 120296-03-9; hexane-d,,, 120296-04-0.
Received for review March 8, 1988 Revised manuscript received November 28, 1988
Accepted January 24, 1989
Supersaturation and Crystallization Kinetics of Potassium Chloride
Ru-Ying Qian,* Xian-Shen Fang, and Zhi-Keng Wang Shanghai Research Institute o f Chemical Industry, Shanghai 200062, People's Republic of China
The crystallization kinetics of potassium chloride from its aqueous solution is studied with a novel temperature float method for supersaturation determination. The relative supersaturation is measured to be (1.1-2.9) X The growth rate is proportional t o the supersaturation over a wide range of retention times and tip speeds, while the nucleation rate increases rapidly with respect to supersaturation. The supersaturation, growth rate, and nucleation rate are independent of tip speed up to 3 m/s. Beyond 3 m/s, the power index of the tip speed in the kinetic equation increases to 4. A change in the dominant nucleation mechanism is discussed. A slight impeller vibration does not affect the power indexes in the kinetic equation but considerably increases the nucleation rate. A temperature difference of 4-6 K between cooling water and bulk suspension leads to extraordinarily high nucleation rates but does not yet affect growth rates.
with a precision of 1 X
The crystallization kinetics of potassium chloride has been studied by many investigators (Genck and Larson, 1972; Ploss et al., 1985; Randolph et al., 1981; Qian...