| 摘要: | 電廠燃煤灰渣為火力發電所產生的燃煤副產品，煤炭經過煤槽、過熱器、再熱器、省煤器、靜電集塵器、脫硫塔等流程燃燒發電，其中隨熱空氣上升的輕質不燃燒物經靜電捕集器從煙氣中捕集到的微細粒狀物稱為飛灰；而從鍋爐底部灰斗取出的灰渣，稱為底灰。
為瞭解燃煤灰渣應用於陶瓷建材的可行性探討，本研究規劃兩個階段進行研究，第一階段：前導試驗分為兩個部分「陶瓷面磚製程建置」、「對照組配比測試」；第二階段：再生陶瓷面磚試驗，以「燃煤灰渣作為陶瓷建材部分原料之研究」進行配比設計及試驗。
前導試驗結果，陶瓷面磚製程為粉體製備完成後以密度2.5 g/cm3壓錠成型後以區段升溫方式高溫燒結，最後決定以黏土含量佔總重量比35%之C35試體作為本研究之對照組。
再生陶瓷面磚試驗內容主要分為兩個變因探討，一為探討燃煤灰渣取代量對陶瓷面磚燒結的影響，使用飛灰與底灰分別以重量取代 10 %、20 %、30 %、40 %、50 %、60 %於陶瓷面磚原料；另一為探討不同燒結溫度對燃煤灰渣取代陶瓷面磚的影響，燒結溫度為1100 °C 、1140 °C、1170 °C、1200 °C；並依據前導試驗確立之試體製作方式進行試驗。
試驗結果顯示，在燃煤灰渣取代量對陶瓷面磚的影響，試體於 1100 °C 高溫燒結後，除底灰取代10%之配比可燒結成 II 類面磚外，其餘配比均可達成III 類面磚之要求；收縮率隨添加量降低，減少體積損耗；翹曲皆符合平整度的規範；抗彎強度皆遠高於規範需求；耐熱衝擊性試驗後皆無產生缺陷；成色方面隨添加量愈趨於棕褐色飽和。在不同燒結溫度對取代燃煤灰渣陶瓷面磚的影響，試體分別於 1140 °C、1170 °C、1200 °C 高溫燒結後，可達成 Ia 類、Ib 類面磚；收縮率同樣隨添加量降低，但在溫度提高後試體厚度發生膨脹情形；翹曲方面因試體膨脹變形嚴重皆不符合於規範；成色方面隨取代量愈增加趨於黑褐色飽和。燃煤灰渣取代的試體於1100 °C 燒結溫度下有較佳的成效，燒結溫度提升後試體變形嚴重，不利於應用。燃煤底灰在低取代量 10BA 時可以達到 II 類面磚標準，強度與翹曲皆能符合規範，在降低成本與提高經濟性的考量下，底灰相較於飛灰有較佳的效果。;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. |
