Index for iron-based slagging for pulverized coal firing in oxidizing and reducing conditions

McLennan, AR Bryant, GW Bailey, CW Stanmore, BR Wall, TF

Ar. Mclennan et al., Index for iron-based slagging for pulverized coal firing in oxidizing and reducing conditions, ENERG FUEL, 14(2), 2000, pp. 349-354

30

INGLESE

Article

Environmental Engineering & Energy

ENERGY & FUELS

0887-0624 → ACNP

14

2

2000

349 - 354

ISI

0887-0624(200003/04)14:2<349:IFISFP>2.0.ZU;2-L

A model for the prediction of iron-based slagging precursors from the combu stion of iron-containing coals is detailed. The model accounts for the form of iron (pyrite or siderite), the distribution of iron within the pulveriz ed coal, temperature, and oxidizing or reducing conditions. The input requi red for the model is a CCSEM analysis of the pulverized coal. For oxidizing conditions, the index predicts similar behavior for pyrite, and siderite-c ontaining coals, with iron alumine-silicate ash particles becoming sticky a t temperatures greater than 1400 degrees C. This suggests that for oxidizin g conditions, the extent of included iron minerals is the most important fa ctor. For reducing conditions, the index predicts sticky ash particles are formed at lower temperatures, as low as 1000 degrees C for pyrite-containin g coals as a result of the decomposition and partial oxidation of pyrite-fo rming sticky particles, and 1100 degrees C for siderite-containing coals. F or reducing conditions, the level of excluded pyrite mineral for pyrite-con taining coals and the level of included iron-containing minerals associated with clays for siderite- and pyrite-containing coals are the most importan t factors determining slagging.