Buradasınız

Anasayfa » Content

Piritin N2 Atmosferinde Isıl Bozunmasına Su Buharının Etkisi

The Effect of Water Vapor on the Thermal Decomposition of Pyrite in N2 Atmosphere

Journal Name:

  • Pamukkale Üniversitesi Mühendislik Bilimleri Dergisi

Publication Year:

  • 2009

Key Words:

Keywords (Original Language):

Author NameUniversity of AuthorFaculty of Author
Abstract (2. Language): 
In this study, the effect of water vapor on the thermal decomposition of pyrite mineral in nitrogen atmosphere has been investigated in a horizontal tube furnace. Temperature, time and water vapor concentration were used as experimental parameters. According to the data obtained at nitrogen/ water vapor environment, it was observed that the water vapor on the decomposition of pyrite in¬creased the decomposition rate. The decomposition reaction is well represented by the "shrinking core" model and can be divided into two regions with different rate controlling step. The rate controlling steps were determined from the heat transfer through the gas film for the low conversions, while it was determined from the mass transfer through product ash layer for the high conversions. The activation energies of this gas and ash film mechanisms were found to be 77 and 81 kJ/mol-1, respectively.
Bookmark/Search this post with
Abstract (Original Language): 
Bu çalışmada pirit mineralinin azot atmosferinde ısıl bozunması üzerine su buharının etkisi yatay bir boru fırın içinde incelendi. Deneysel parametreler olarak sıcaklık, zaman ve su buharı konsantrasyo¬nu kullanıldı. Azot/su buharı ortamında elde edilen verilere göre, piritin bozunması üzerine su bu¬harının bozunma hızını arttırdığı gözlemlendi. Bozunma reaksiyonunun, "büzülen çekirdek modeli" ile iyi uyum sağladığı ve farklı hız kontrol basamaklı iki bölgeye ayrıldığı belirlendi. Hız kontrol basa¬makları, düşük dönüşümlerde akışkan filminden ısı transfer kontrollü, yüksek dönüşümlerde ise kül filminden difüzyon kontrollü olduğu tespit edildi. Bu gaz ve kül filmi mekanizmalarının aktivasyon enerjileri sırası ile 77 ve 81 kJ/mol-1 olarak bulundu.
FULL TEXT (PDF): 
PDF icon arastirmax-piritin-n2-atmosferinde-isil-bozunmasina-su-buharinin-etkisi.pdf
  • 3
427
432
  • Turkish

REFERENCES

References: 

Boyabat, N., Özer, A. K., Bayrakceken, S., Gülabo-glu, M. S. 2003. Thermal decomposition of pyrite in the nitrogen atmosphere, Fuel Process Tech-nol. (85), 179-188.
Coats, A. W. and Bright, N. F. H. 1966. The kinet¬ics of thermal decomposition of pyrite, Can. J. Chem. (44), 1191-1195.
Hansen, J. P., Jensen, L. S., Wedel, S. and Dam-Jo-hansen, K. 2003. Decomposition and oxidation of pyrite in a fixed-bed reactor, Ind. Eng. Chem.
Res. (42), 4290-4295.
Hoare, I. C., Hurst, H. J., Stuart, W. I. 1988. Ther¬mal decomposition of pyrite, J. Chem. Soc.
Faraday Trans. I, 84 (9), 3071-3077.
Hong, Y. and Fegley, B. 1997. The kinetics of mechanism of pyrite thermal decomposition, Ber. Bunsenges. Phys. Chem. (101), 1870-1881.
Hu,
H.
, Chen, Q., Yin, Z., Zhang, P., Zou, J., Che, H. 2002. Study on the kinetics of thermal decom¬position of mechanically activated pyrites, Ther-mochimica Acta. (389), 79-83.
Hu,
H.
, Chen, Q., Yin, Z., Zhang, P. 2003. Thermal behaviors of mechanically activated pyrites by thermogravimetry (TG), Thermochimica Acta. (398), 233-240.
Hu, G., Dam-Johansen, K., Wedel, S., Hansen, J. P. 2006. Decomposition and oxidation of pyrite, Progress in Energy and Combustion Science. (32), 295-314.
Jovanovic, Dj. 1989. Kinetics of Thermal Decom¬position of pyrite in an inert atmosphere, J. of
Thermal Analysis. (35), 1483-1492.
Lambert, J. M., Simkovich, G, and Walker, P. L. 1998. The kinetics and mechanism of the py-rite-to-pyrrhotite Transformation, Metall Mater Trans B, 29B, 385-396.
Levenspiel, O, 1999. Chemical Reaction Engi¬neering, 3rd ed.; John Wiley: New York.
Levy, J. H., and White, T.J. 1988. The reaction of pyrite with water vapor. Fuel. (67), 1336 -1339.
Longhurst, J. W. S., Raper, D. W., Lee, D. S., Bridget, A. H., Conlan, B. and King, H. J. 1993. Acid Deposition: a Select Review, 1852-1990, Fuel. (72),
1261-1280.
Monteiro, J. L. F. 1981. Thermal decomposition of pyrite in a fluidized bed, the can. J. of Chem. Eng. (59), 511-516.
Schwab, G. M., Philinis, J. 1947. Reactions of Iron Pyrite: Its Thermal Decomposition, Reduction by Hydrogen and Air Oxidation, J Am Chem Soc.
69 (11), 2588-2596.
Yamazaki, S., Asaki, Z. and Kondo, Y. 1968. Ther¬mal decomposition of pyrite in a fluidized bed, Trans. of the Metall. Soc. of Aime. (242), 896-902.
Yan,
J.
, Xu, L., Yang, J. 2008. A study on the ther¬mal decomposition of coal-derived pyrite, J. Anal. Appl. Pyrolysis. (82), 229-234.
Watkinson, A. P. And Germain, C. 1972. Thermal decomposition of pyrite in fluidized Beds, Can. Metall.Quartery. 11 (3), 535-547.
Wiltowski, T., Hincley, C. C. And Smith, G. W. 1987. Kinetics and mechanisms of ıron sulfide reductions in hydrogen and carbon monoxide, J. of Solid State Chem. (71), 95-102.

Thank you for copying data from http://www.arastirmax.com