【摘要】：燃煤發(fā)電一直以來都是我國電力工業(yè)的主要形式，且未來很長一段時期內(nèi)，這種電力結構不會改變，煤炭燃燒所產(chǎn)生的含有SO2等有害氣體的廢氣是造成環(huán)境污染的一個重要因素。為了適應國家對資源、環(huán)境可持續(xù)發(fā)展的政策導向，，燃煤電廠煙氣脫硫技術應運而生，同時，作為煙氣脫硫的副產(chǎn)物——脫硫石膏，其產(chǎn)量逐年增多。脫硫石膏是與天然石膏具有很多共性的資源，主要成分為二水石膏，產(chǎn)量大、成本低，是天然石膏的最佳替代品。但其顆粒形態(tài)、雜質(zhì)組分等因素又導致它在脫水性、結晶程度、流變形、觸變性、收縮性、易磨性等方面與天然石膏有著明顯的差異。因此，對脫硫石膏綜合利用的研究具有重要的實際意義。 煅燒制度是決定脫硫石膏制品的性能及適用條件的關鍵因素，本文通過對脫硫石膏進行熱重分析，分析脫硫石膏的相變溫度范圍，選定不同的煅燒溫度分別對脫硫石膏進行熱處理，比較不同煅燒制度處理后脫硫石膏的強度、耐水性能等，并通過XRD、SEM等微觀分析手段對水化產(chǎn)物進行分析，最終發(fā)現(xiàn)脫硫石膏在煅燒時間為1.5h，煅燒溫度設定在180℃時，其水化產(chǎn)物表現(xiàn)出最佳的物理性能。 氯離子作為脫硫石膏中主要的雜質(zhì)元素，對脫硫石膏及其制品性能的發(fā)揮有著不可忽視的影響。由煙氣脫硫產(chǎn)生的脫硫石膏中氯離子含量普遍超過標準，這直接導致了脫硫石膏產(chǎn)品性能各異，品質(zhì)相差較大。本文通過實驗研究了氯離子對脫硫石膏脫水性能以及對其水化產(chǎn)物耐水性能和紙面石膏板紙板粘接性能的影響，并借助微觀分析手段綜合分析了造成這一現(xiàn)象的原因。結果表明，氯離子含量越高，脫硫石膏脫水越困難，但當含量超過6000ppm時，石膏含水率基本趨于穩(wěn)定。氯離子對水化產(chǎn)物的吸水率，軟化系數(shù)，強度，石膏板紙板粘接性能均有不利影響。 為了探索改善氯離子對脫硫石膏制品性能影響的方法，改變脫硫石膏的應用現(xiàn)狀，提高其工業(yè)附加值。本文研究了有機硅防水劑、礦物摻合料以及水灰比等對氯離子在脫硫石膏制品（以紙面石膏板為例）中的遷移情況以及對制品性能的影響。結果表明，摻加適量的防水劑不僅可以有效地提高紙面石膏板的紙板粘接能力,還能改善其耐水性能；摻加適量的礦物摻合料可以在不影響石膏制品性能的前提下提高對氯離子的固化能力；水灰比同樣對石膏板中氯離子的遷移及紙板粘接性能有重要影響，在不影響其工作性的前提下，水灰比越低，對氯離子的固化效果越好。有機硅防水劑的最佳摻量為1.5%；礦物摻合料的最佳摻量如下：水泥2%，粉煤灰4%，礦渣6%。制備出了一種外加劑-礦物摻合料復合固氯劑，其基本組分為防水劑1%，水泥1.2%，粉煤灰2.4%，礦渣3.6%,減水劑2.2%（與石膏的質(zhì)量百分比），該固氯劑對改善氯離子對脫硫石膏制品性能影響的作用明顯。
[Abstract]:Coal-fired power generation has always been the main form of the power industry in China, and this kind of power structure will not change for a long time to come. The waste gas containing SO2 and other harmful gases produced by coal combustion is an important factor of environmental pollution. In order to adapt to the national policy of sustainable development of resources and environment, flue gas desulfurization (FGD) technology in coal-fired power plants came into being. At the same time, as a by-product of FGD, the output of FGD gypsum increased year by year. Desulphurized gypsum is a common resource with natural gypsum. It is the best substitute for natural gypsum because of its large output and low cost. However, the particle morphology, impurity composition and other factors lead to its dewatering, crystallinity, fluid deformation, thixotropy, shrinkage, abrasive property and so on, which are obviously different from those of natural gypsum. Therefore, the study of comprehensive utilization of desulphurized gypsum has important practical significance. The calcination system is the key factor to determine the properties and applicable conditions of desulfurized gypsum products. By thermogravimetric analysis of desulphurized gypsum, the temperature range of phase change of desulphurized gypsum is analyzed. Heat treatment of desulphurized gypsum was carried out at different calcination temperatures. The strength and water resistance of desulphurized gypsum after different calcination systems were compared, and the hydration products were analyzed by means of micro-analysis such as XRDX SEM. It was found that the hydration products of desulphurized gypsum exhibited the best physical properties when the calcination time was 1.5 h and the calcination temperature was 180 鈩

本文編號：2148007