矸石电厂CFB灰渣在水泥混凝土中的应用研究

发布时间：2018-03-06 04:17

  本文选题：矸石电厂　切入点：CFB粉煤灰　出处：《武汉理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着国内煤矸石电厂的增加,其排放的固体废弃物CFB(循环流化床)灰渣大量堆积填埋。为促进CFB灰渣的利用,以中煤华昱煤矸石循环经济产业园为依托,开展了CFB灰渣特性及在水泥混凝土中的应用研究。提出了利用CFB粉煤灰替代普通粉煤灰与矿粉配制混凝土,并在此基础上研制出了以CFB粉煤灰为主体的具有微膨胀性能的路面基层专用水泥,初步研究了其对水泥稳定材料抗裂性能的影响。研究结果如下:(1)CFB灰渣中的Loss、CaO及SO3含量随脱硫工艺及入炉煤的改变有较大波动。原状CFB灰渣的需水量极大且火山灰活性低,这与其微观疏松多孔的的内部结构有关,机械活化后CFB粉煤灰的需水性急剧下降,且28d的火山灰活性呈跨越式增长,高达95%。(2)由不同种类的CFB灰渣对比分析可得:炉渣的需水性低于粉煤灰,但是易磨性差,早期活性低。CFB锅炉的炉温对灰渣的活性影响显著,其中900℃低温粉煤灰的活性指数高达95%以上,而高温型粉煤灰F1的活性仅为75%,各种不同灰渣的28d活性指数大小排序为:XF2≈F2C2C1F1。(3)CFB灰渣作为水泥混合材时,会使得水泥的标准稠度需水量迅速上升,对减水剂的吸附性强,导致水泥浆体的流动度损失较快,但是使用分子量大的聚羧酸减水剂,利用其“空间位阻”效应可以有效改善水泥浆体的流动性能。CFB灰渣水泥的后期增长幅度大,50%掺量的F2与XF2的28d力学强度均能达到55MPa以上。CFB粉煤灰水泥替代P.O42.5水泥、普通粉煤灰及部分矿粉配制混凝土,早期强度稍有下降,但是后期强度高,完全满足C30混凝土对力学性能的要求。(4)利用XF2的高火山灰活性及CaO、SO3膨胀组分,研制出了以CFB粉煤灰为主体的路面基层专用水泥,其基本配比为:熟料30%,石膏3%(SO3含量5.2%)、XF2粉煤灰67%,将其应用于水泥稳定碎石中,结果表明,CFB路面基层专用水泥稳定材料的7d无侧限抗压强度稍低于P.C32.5,但是28d及90d的强度明显高于后者,且路面基层专用水泥的的微膨胀作用补偿了收缩,密实了内部孔隙,极大地改善了水泥稳定材料的抗裂性能。
[Abstract]:With the increase of coal gangue power plant in China, the solid waste CFB (circulating fluidized bed) ash discharged from the coal gangue is piled up and landfilled in large quantities. In order to promote the utilization of CFB ash, it relies on Huayu Coal gangue Recycling Economic Industrial Park of China Coal Mine. The characteristics of CFB ash and its application in cement concrete were studied. It was put forward that CFB fly ash should be used to prepare concrete instead of ordinary fly ash and mineral powder. On the basis of this, a special cement for pavement base with CFB fly ash as the main body with micro-expansion performance is developed. The effect of CFB on crack resistance of cement stabilizer was studied. The results are as follows: the contents of Lossn Cao and SO3 in CFB slag fluctuate with the change of desulfurization process and coal. The water requirement of raw CFB ash is great and the activity of pozzolanic ash is low. This is related to the micro porous internal structure. After mechanical activation, the water demand of CFB fly ash decreases sharply, and the pozzolanic activity of 28 days increases by leaps and bounds. According to the comparative analysis of different kinds of CFB ash, it can be found that the water requirement of slag is lower than that of fly ash, but the grindability is poor. The activity index of fly ash at 900 鈩，

本文编号：1573290