Powiadomienia systemowe
- Sesja wygasła!
Identyfikatory
Warianty tytułu
Języki publikacji
Abstrakty
Pyrite (FeS2) is known as a sulfide that provides energy for various pyrometallurgical processes (fusion and conversion). There are several studies related to the evaluation of pyrite oxidation mechanisms at high temperatures, obtaining discrepancies in the products generated. In our work, the novelty of our research would be to obtain the thermochemical oxidation mechanism of FeS2 by using conventional thermogravimetric methods. The oxidative roasting of pyrite from 550 to 800°C was analyzed for an oxygen concentration of 5.07 to 28.06 kPa of oxygen and particle size between 12.3 to 33.8 microns. The results showed that the pyrite proceeded by sequential roasting: first, it produced an intermediate compound, pyrrhotite (Fe7S8), which was later oxidized to generate hematite (Fe2O3), both stages validated by weight loss of the sample as well as by analysis by DRX. Each stage had a different roasting speed as it was also influenced differently by different parameters. The temperature and particle size favored the rate of pyrrhotite generation, and the oxygen concentration favored the rate of hematite formation. The first-order kinetic equation ln (1-XPy) represented the roasting of the first stage (FeS2 → Fe7S8), with a calculated activation energy of 70.1 kJ/mol. The order of reaction was 0.5 concerning the partial pressure of oxygen and inversely proportional to the initial particle radius.
Słowa kluczowe
Rocznik
Tom
Strony
127--139
Opis fizyczny
Bibliogr. 22 poz., rys. kolor., tab., wykr.
Twórcy
autor
- Escuela de Ingeniería Química, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2162, Valparaíso 2362854, Chile
autor
- Instituto de Geología Económica Aplicada (GEA), Universidad de Concepción, Casilla 160-C, Concepción, Chile
Bibliografia
- ARACENA, A., JEREZ, O., ANTONUCCI, C., 2016a. Senarmontite volatilization kinetics in nitrogen atmosphere AT roasting/melting temperatures, Transactions of Nonferrous Metals Society of China, 26, 294-300.
- ARACENA, A., JEREZ, O., ORTIZ, R., MORALES, J., 2016b. Pyrite oxidation kinetics in an oxygen-nitrogen atmosphere at temperatures from 400 to 500°C, Canadian Metallurgical Quarterly, 55, 195-201.
- BHARGAVA, S.K., GARG, A., SUBASINGHE, N.D., 2009. In situ high-temperature phase transformation studies on pyrite, Fuel, 88, 988-993.
- BOYABAT, N., ÖZER, A.K., BAYRAKCEKEN, S., GÜLABOGLU, M.S., 2004. Thermal decomposition of pyrite in the nitrogen atmosphere. Fuel Process Technol, 85, 179–88.
- DUNN, J.G., DE, G.C., O’CONNOR, B.H., 1989a. The effect of experimental variables on the mechanism of the oxidation of pyrite: Part 1. Oxidation of particles less than 45 μm in size. Thermochim Acta, 145, 115-130.
- DUNN, J.G., DE, G.C., O’CONNOR, B.H., 1989b. The effect of experimental variables on the mechanism of the oxidation of pyrite: Part 2. Oxidation of particles of size 90–125 μm. Thermochim Acta, 155, 135-149.
- GROVES, S.J., WILLIAMSON, J., SANYAL, A., 1987. Decomposition of pyrite during pulverized coal combustion, Fuel, 66, 461-466.
- HANSEN, J.P., 2003. SO2 Emissions from Cement Production. PhD Thesis, Department of Chemical Engineering, Technical University of Denmark.
- HELBLE, J.J., SRINIVASACHAR, S., BONI, A.A., 1990. Factors influencing the transformation of minerals Turing pulverized coal combustion, Progress in Energy and Combustion Science, 16, 267-279
- HONG Y., FEGLEY, B., 1997. The kinetics and mechanism of pyrite thermal decomposition. Ber. Bunsen. Phys. Chem., 101, 1870-1881.
- HONG, Y., FEGLEY, B., 1998. The sulfur vapor pressure over pyrite on the surface of Venus. Planet and Space Science, 46, 683–90.
- HSC Chemistry, version 6.0, OutoKumpu Research Py: Pori, Finland, 1999.
- HUFFMAN, G. P., HUGGINS, F.E., LEVASSEUR, AA., 1989. Investigations of the transformations of pyrite in a droptube furnace. Fuel, 68, 485-490.
- JORGENSEN, F., MOYLE, F.J., 1982. Phases formed during the thermal analysis of pyrite in air, Journal of Thermal Analysis, 25, 473-485.
- KOMRAUS, J.L., POPIEL, E.S., MOCEK, R., 1990. Chemical transformations of ferruginous minerals during the process of oxidation of hard coal. Hyperfine Interact, 58, 2589-2592.
- KUBASCHEWSKI, O., 1982. Iron-binary phase diagrams. Iron–sulphur. Berlin: Springer, pp. 125.
- MCLENNAN, A.R., BRYANT, G.W., STANMORE, B.R., WALL, T.F., 2000. Ash formation mechanisms during of combustion in reducing conditions, Energy Fuels, 14, 150-159.
- MITOVSKI, A., STRBAC, N., MANASIJEVIC, D., SOKIC, M., DAKOVIC, A., ZIVKOVIC, D., BALANOVIC, Lj., 2015. Thermal analysis and kinetics of the chalcopyrite-pyrite concentrate oxidation process, Metalurgija, 54, 311-314.
- NISHIHARA, K., KONDO, Y., 1959. Studies of the oxidation of Pyrite I, II and III. Mem Fac. Eng., Kyoto Univ., 21, 214-218.
- SCHORR, J.R., EVERHART, J.O., 1969. Thermal behavior of pyrite and its relation to carbon and sulfur oxidation in clays. Journal of the American Ceramic Society, 52, 351-354.
- PRASAD, A., SINGRU, R.M., BISWAS, A.K., 1985. Study of the roasting of pyrite minerals by Mössbauer spectroscopy, Physical Status Solidi A, 87, 267-271.
- SRINIVASACHAR, S., HELBLE, J.J., BONI, A.A., 1990. Mineral behavior during coal combustion 1. Pyrite transformation, Progress in Energy and Combustion Science, 16, 281-292.
Typ dokumentu
Bibliografia
Identyfikator YADDA
bwmeta1.element.baztech-e4b6b9cc-40ae-452d-b8e1-b741866b539e