| dc.description.abstract | Coal-fired ash and slag in power plants are by-products of coal-fired power generation. Coal is burned to generate electricity through processes such as coal troughs, superheaters, reheaters, economizers, electrostatic precipitators, and desulfurization towers. The fine particulate matter captured from the flue gas by the electrostatic collector is called fly ash; and the ash taken out from the ash hopper at the bottom of the boiler is called bottom ash.
In order to understand the feasibility of using coal-fired ash and slag in ceramic building materials, this study plans to conduct research in two stages. The first stage: the pilot test is divided into two parts, ＂the construction of the ceramic tile manufacturing process＂ and ＂the control group ratio test＂; The second stage: the test of recycled ceramic tiles, the proportion design and test are carried out with ＂coal-fired ash and slag as part of the raw materials of ceramic building materials＂.
In the preliminary test results, the ceramic tiles are manufactured by pressing the ingots with a density of 2.5 g/cm3 and then sintering them at high temperature in a zone heating process. Finally, the C35 sample with a clay content of 35% by weight is used as the control group for this study. The experiments on recycled ceramic tiles are divided into two variables, one is to investigate the effect of coal-fired ash replacement on the sintering of ceramic tiles, and the other is to investigate the effect of different sintering temperatures on the ceramic tiles with replaced coal-fired ash. The test is carried out according to the sample production method decided by the preliminary test, and the test results are shown as follows:
The effect of coal-fired ash substitution on ceramic tiles. In this study, fly ash and bottom ash were partially replaced by 10 %, 20 %, 30 %, 40 %, 50 % and 60 % of the raw material for ceramic tiles, and the samples were sintered at 1100 °C to form Type II and Type III tiles; the shrinkage rate decreases with the addition amount, reducing the volume loss; the warpage meets the flatness specification; the flexural strength is far higher than the specification requirements; no defects after thermal shock testing; the brown color saturation increased with the increase of the addition amount. The effect of different sintering temperatures on the replacement of coal-fired ash ceramic tiles, after the samples were sintered at 1140 °C, 1170 °C and 1200 °C, can be reached for Type Ia and Ib tiles; the shrinkage rate also decreased with the addition amount, but the thickness of the specimen expands after the temperature is increased; the warpage is not in accordance with the specification due to the serious expansion and deformation of the specimen; the dark brown color saturation increased with the increase of the addition amount.
The samples with coal-fired ash substitution have better results at 1100 °C sintering temperature, but after the sintering temperature is raised, the sample is seriously deformed, which is not conducive to application. The coal-fired bottom ash in a low replacement amount of 10BA can reach Type II tile specification, and the strength and warpage can meet the specification. In consideration of cost reduction and economic improvement, bottom ash has a better effect compared to fly ash. | en_US |