Decomposition of pyrite during pulverized coal combustion
| Autor: | J. Williamson, S.J. Groves, A. Sanyal |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
Pulverized coal-fired boiler
General Chemical Engineering Organic Chemistry Metallurgy Energy Engineering and Power Technology chemistry.chemical_element engineering.material Combustion Nitrogen Sulfur chemistry.chemical_compound Fuel Technology chemistry Agglomerate engineering Pyrite Pyrrhotite Magnetite |
| Zdroj: | Fuel. 66:461-466 |
| ISSN: | 0016-2361 |
| DOI: | 10.1016/0016-2361(87)90148-7 |
| Popis: | The decomposition of pyrite in air, 2% oxygen in nitrogen and nitrogen atmospheres, has been studied at temperatures ranging from 300 to 1100 °C. Pyrite was found to lose sulphur from 300 °C upwards, to form pyrrhotite and haematite. In both 2% O 2 and N 2 , magnetite forms above 800 °C in preference to haematite. In 2% O 2 , an atmosphere which closely resembles boiler conditions, the maximum amount of haematite was found in the range 800–900 °C. Drop-tube experiments, using finely ground pyrite and pyrrhotite as starting materials, have shown that liquid iron sulphides form from 1000 °C upwards. This enables a deposit to adhere well to a metal substrate surface. Microstructural analysis has shown that these deposits consist of deformed spherical agglomerates with a porous internal structure. Burner impeller deposits, rich in iron, taken from a pulverized coal-fired utility boiler have been examined. By comparing the microstructures of the deposits with those from the drop-tube experiments, it has been possible to propound a mechanism for their formation. Preferential deposition of liquid iron sulphides followed by in situ oxidation, is believed to be the mechanism by which these deposits form. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|