Kinetics of the fe2+-mg, order-disorder reaction in anthophyllites: quantitative cooling rates - PubMed (original) (raw)
Kinetics of the fe2+-mg, order-disorder reaction in anthophyllites: quantitative cooling rates
F A Seifert et al. Science. 1975.
Abstract
The kinetics of the Fe(2+)-Mg, order-disorder phenomenon in a highly ordered natural anthophyllite have been determined over the temperature range from 400 degrees to 720 degrees C at a pressure of 2 kilobars. At temperatures of 600 degrees C and above, equilibrium is attained by disordering as well as ordering reactions. The intracrystalline exchange is defined by a standard Gibbs free energy of 4247 +/- 54 calories per formula unit. Rate studies at 550 degrees and 500 degrees C show that equilibrium is attained by ordering but not by disordering within the same time scale and that the exchange reaction is characterized by an activation energy of approximately 55 kilocalories per formula unit. An equilibration temperature for the natural anthophyllite of 270 degrees C is determined from the termination of the ordering process owing to excessively slow reaction kinetics after approximately 10(7) years. From the rate constants of the exchange process, for different crystallization temperatures, the apparent equilibration temperature of 270 degrees C defines a maximum linear cooling rate for the rock of 1 x 10(4) degrees C per year.
Similar articles
- Catalytic combustion of volatile organic compounds.
Everaert K, Baeyens J. Everaert K, et al. J Hazard Mater. 2004 Jun 18;109(1-3):113-39. doi: 10.1016/j.jhazmat.2004.03.019. J Hazard Mater. 2004. PMID: 15177752 - Thermal and structural behavior of milk fat. 3. Influence of cooling rate and droplet size on cream crystallization.
Lopez C, Bourgaux C, Lesieur P, Bernadou S, Keller G, Ollivon M. Lopez C, et al. J Colloid Interface Sci. 2002 Oct 1;254(1):64-78. J Colloid Interface Sci. 2002. PMID: 12702426 - [Isothermal ordering processes of equiatomic alloy CuPt (author's transl)].
Hisatsune K. Hisatsune K. Shika Rikogaku Zasshi. 1979 Apr;20(50):104-10. Shika Rikogaku Zasshi. 1979. PMID: 290704 Japanese. - The effects of excessive humidity.
Williams RB. Williams RB. Respir Care Clin N Am. 1998 Jun;4(2):215-28. Respir Care Clin N Am. 1998. PMID: 9648183 Review.
Cited by
- Inferred time- and temperature-dependent cation ordering in natural titanomagnetites.
Bowles JA, Jackson MJ, Berquó TS, Sølheid PA, Gee JS. Bowles JA, et al. Nat Commun. 2013;4:1916. doi: 10.1038/ncomms2938. Nat Commun. 2013. PMID: 23715275
LinkOut - more resources
Full Text Sources