快速流化床煅烧温度对脱硫石膏性能的影响

Effect of firing temperature in fast fluidization bed on mechanism properties of flue gas desulfurization gypsum

为提高脱硫石膏煅烧效率及产品质量,设计了一种新型快速流化床煅烧装置。在14.5 m/s的操作流化风速下,对不同煅烧温度条件下脱硫石膏性能进行了分析,以便确定最佳的操作条件。试验结果表明:提高煅烧温度至386℃时,原状脱硫石膏脱水率接近100%;当煅烧温度高于250℃后,脱水脱硫石膏的矿相由CaSO_4·0.5H_2O和CaSO_4·0.67H_2O两相构成。416℃范围内没有发现AⅡ-CaSO_4相存在。煅烧温度与脱水脱硫石膏比表面积、标准稠度用水量均呈线性关系。煅烧温度提高后脱水脱硫石膏再水化硬化体致密性显著增加,试样力学性能同样得以提高。当快速流化床煅烧温度为386℃,脱硫石膏脱水率可达99.3%,力学性能最佳。

A new equipment for increasing firing efficiency of flue gas desulfurization gypsum （FGD） and product quality was designed,based on principle of fast fluidization bed. In order to confirm the optimal operating conditions,the properties of flue gas desulfurization gypsum under different firing temperature were analyzed at operating fluidizing velocity of 14.5 m/s. The results showed that original FGD can be almost entirely dehydrated above 386℃. When the firing temperature is over 250 ,mineral composition of FGD dehydrated consist of CaSO4 0.5H20 and CaSO4 0.67H20 phase,with absence of A]I-CaSO4 below 416 ℃. Specific surface area and water requirement of normal consistency of FGD dehydrated are linearly improved,following increasing fir- ing temperature. Compactness of the hardened specimen is obviously improved,resuhing in mechanical properties increasing after FGD dehydrated under higher firing temperature are rehydrated. Dehydration rate of FGD reach 99.3% with optimal strength at fir- ing temperature of 386 ℃.