Influence of microwave oven calcination on the pozzolanicity of sugar cane bagasse ashes (SCBA) from the cogeneration industry

Abstract

[EN] This study evaluates the effects of microwave oven calcining conditions on the pozzolanicity of sugar cane bagasse ashes (SCBA) generated by the electric power cogeneration industry. The calcining temperatures varied between 600 ºC and 800 ºC, and the permanence times were 60 min in an electric oven and 30, 45 and 60 min in a microwave oven. To evaluate the behaviour of the ashes according to different calcining conditions, we carried out the following analyses: granulometric distribution (laser diffraction), oxide percentages (XRF), loss on ignition (LOI), powder X-ray diffraction (XRD), pozzolanic reactivity, determination of amorphous silica content and thermogravimetry of hydrated lime pastes (DTG). The results show that SCBA calcination in a microwave oven results in ashes with greater pozzolanic reactivity and a significantly more efficient burning process than in an electric oven.