硅质尾矿火山灰活性的机械力化学活化研究

发布时间：2018-06-12 23:47

  本文选题：硅质尾矿 + 机械力化学活化　； 参考：《山东科技大学》2017年硕士论文

【摘要】：硅质尾矿作为我国选矿尾矿的主要类型之一,其化学成分以SiO2、Al2O3为主,这与火山灰质材料近似,具备与Ca(OH)2反应生成水硬性物质的潜在性能。本文以激发硅质尾矿的火山灰活性为目的,研究机械粉磨、化学激发剂对硅质尾矿火山灰活性的活化作用,以及活化尾矿在尾矿复合水泥中的应用。机械粉磨研究表明,尾矿的火山灰活性随其比表面积的不断增加而显著增强。未粉磨时,尾矿的比表面积为233.20m2/kg, 28d活性指数仅为53.89%,当粉磨至5min,尾矿的比表面积达到495.10m2/kg,28d活性指数达到65.65%,粉磨至45min,在比表面积为849.40m2/kg, 28d活性指数达到峰值为80.94%。在尾矿与粉煤灰混合研磨试验中,比例为1: 1时,比表面积达到1169.80m2/kg,28d抗压强度就可以达到50.25MPa,28d活性指数为94.56%,此数据明显高于尾矿单独的粉磨活性(尾矿单独粉磨时,比表面积为1161.70m2/kg时,28d抗压强度为37.61MPa,28d活性指数为73.78%)。CaO和CaCl2对硅质尾矿混合材料具有较好的早强作用,CaO的适宜掺量为2%,此时试样的比表面积为880.40m2/kg,3d抗压强度达到22.25MPa,28d活性指数为81.88%; CaCl2的适宜掺量为1%,此时比表面积为903.90m2/kg, 3d抗压强度达到22.14MPa,28d活性指数为81.74%。通过活化尾矿在尾矿复合水泥中应用性能的研究,发现掺加尾矿后水泥的凝结时间伴随着尾矿的比表面积增加而逐渐降低,体系中的水泥标准稠度用水量也逐渐增大。在尾矿比表面积达到840.30m2/kg,掺加量为30%时,可以满足P·Ⅱ425要求,28d的抗折、抗压强度为6.86MPa、43.91MPa,凝结时间为201min、253min,标准稠度用水量为28.20%,安定性合格;将尾矿与粉煤灰进行复配比例为1: 1用作复合水泥的混合材料,比表面积达到1175.50m2/kg时,满足P·Ⅱ425要求混合材料的掺加量可以达到50%,水泥28d的抗折、抗压强度为7.09MPa、43.77MPa,凝结时间为237min、311min,标准稠度用水量为29.80%,安定性合格。
[Abstract]:As one of the main types of tailings in China, siliceous tailings are mainly composed of Sio _ 2 and Al _ 2O _ 3, which are similar to pozzolanic materials and possess the potential properties of reacting with CaOH ~ (2 +) to form hydraulics. In order to activate the pozzolanic activity of siliceous tailings, this paper studies the activation of mechanical grinding, chemical activator on pozzolanic activity of siliceous tailings, and the application of activated tailings in tailings composite cement. The results of mechanical grinding show that the pozzolanic activity of tailings increases with the increase of specific surface area. The specific surface area of tailings is 233.20 m2 / kg, and the activity index of 28 days is only 53.89. When grinding to 5 min, the specific surface area of tailings reaches 495.10 m ~ 2 / kg ~ (2) kg ~ (28) d activity index is 65.65%, grinding time is 45 min, the specific surface area is 849.40 m ~ (2 / kg) 路kg, and the activity index of 28 days is 80.94 cm ~ (-1). When the ratio of tailings to fly ash is 1: 1, the specific surface area reaches 1169.80 m ~ 2 / kg ~ (-1) 路kg ~ (-1) and the compressive strength reaches to 50.25 MPA ~ (28) d. The activity index is 94.56, which is obviously higher than that of tailings' sole grinding activity. When the specific surface area is 1161.70m2/kg, the compressive strength is 37.61MPa / 28d and the activity index is 73.78. Cao and CaCl2 have a better early strength effect on siliceous tailings mixture. The suitable addition amount of Cao is 2. The specific surface area of the sample is 880.40m-2 / kg3d and the compressive strength is 22.25MPa/ 28d. The optimum content of CaCl2 is 1, the specific surface area is 903.90 m2 / kg, the compressive strength of 3 days is 22.14 MPA / 28d and the activity index is 81.74. Through the study of the application performance of activated tailings in tailing composite cement, it is found that the setting time of cement with tailings increases with the increase of specific surface area of tailings, and the water consumption of cement standard consistency in the system increases gradually. When the specific surface area of tailings reaches 840.30m2 / kg and the addition amount is 30cm, it can satisfy the requirements of P 鈪，

本文编号：2011599