摘要
通过X线衍射(XRD)分析、热分析等方法分析粉煤灰-石灰体系在压蒸工艺条件下产物的形成,采用盐酸选择性溶解法对压蒸试样中粉煤灰反应程度进行定量分析,结合压蒸试样中石灰的反应程度,对水热反应产物生成量进行定量计算。结果表明:在粉煤灰-石灰压蒸体系中,发生水热反应生成水化硅酸二钙(C_2SH)、水化铝酸三钙(C_3AH_6)、水化石榴石(C_3ASH_4)等产物。粉煤灰配料为78%的压蒸试样,当压蒸工艺参数从4 h、120℃提高至6 h、160℃时,粉煤灰反应程度提高了50%,CaO反应程度提高了32.59%,其游离CaO(f-CaO)质量分数降低了46.49%,此时C_2SH形成量范围从6.94%~17.69%提高至13.87%~17.46%,C_3ASH_4的形成量范围从2.91%~5.99%提高至15.03%~16.08%。确定最佳石灰掺加比例是22%,最佳压蒸工艺参数为140℃、8 h或160℃、6 h以上。
The formation of hydrothermal reaction products in fly ash-lime system by autoclaving were investigated by X-ray diffraction analysis(XRD)and thermal analysis.HCl selective dissolution method was used for quantitative analysis of fly ash reaction degree.Combined with quantitative analysis of lime reaction degree,the content of hydrothermal reaction products were estimated.Results showed that dicalcium silicate hydrate(C2SH),tricalcium aluminate hydrate(C3AH6)and hydrogarnet(C3ASH4)were synthesized by hydrothermal reaction in fly ash-lime system under autoclaving.With the increase of autoclaving parameters from4h an120℃to6h and160℃,the content of C2SH and C3ASH4increased from6.94%-17.69%to13.87%-17.46%and2.91%-5.99%to15.03%-16.08%respectively,reaction degree of fly ash increased by50%,reaction degree of CaO increased by32.59%and free CaO(f-CaO)mass concentration reduced by46.49%in autoclave sample with fly ash ratio of78%.Experimental results showed that the optimal ratio of lime was22%,the appropriate autoclaving parameters were140℃and8h or160℃and6h or more,respectively.
作者
曹瑞林
徐玲玲
黄蓓
杨南如
CAO Ruilin;XU Lingling;HUANG Bei;YANG Nanru(College of Materials Science and Engineering,Nanjing Tech University,Nanjing 210009,China;Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM),Nanjing 210009,China)
出处
《南京工业大学学报（自然科学版）》
CAS
北大核心
2018年第1期81-88,共8页
Journal of Nanjing Tech University(Natural Science Edition)
关键词
粉煤灰
水热合成
水化产物
反应程度
fly ash
hydrothermal synthesis
hydration products
reaction degree
