Effect of hydration conditions on the physical properties of fly ash-Ca(OH)₂ sorbents

Fly ash samples taken from three different coal-fired power plants in Turkey were used as reagent material for the production of reactive sulfur dioxide sorbents. For this purpose, fly ash-Ca(OH)₂ mixtures with different weight ratios were hydrated under different conditions. The effects of the hydration condition such as temperature, time, and fly ash / Ca(OH)₂ weight ratio on the physical properties of activated sorbents were investigated. A statistical design technique was applied by use of two-level factorial design matrix to interpret experimental results. It was found that increasing the temperature and hydration time caused an increase in the total surface area of the sorbents. However, except for one case, surface area values were generally not changed significantly for sorbents obtained from mixtures that have different fly ash / Ca(OH)₂ weight ratios.