Sulphur Dioxide Emissions during the Firing of Ceramic Bodies Based on Class C Fly Ash

摘要

Fluid fuel combustion technology in coal-fired power plants is very popular in the Czech Republic, resulting in a relatively high production of a specific by-product - fluidized fly ash (class C according to ASTM definition), which differs from the classical high-temperature fly ash in mineralogical composition with a high sulfur content of anhydrite CaSO_4. Fluidized ash is not yet used in the production of fired building materials, where it could be used as a source of calcium oxide (for example, the production of porous ceramic tiles). However, high volume of sulfur dioxide emissions during the re-firing of fluidized fly ash in ceramic raw materials mixtures has been solved. The aim of the paper is definition of temperature ranges of anhydrite decomposition (formation of SO_2 emission) from pure class C (fluidized) fly ashes from different sources (power plants) depending on granulometry of fly ash especially.