Quantitative analysis of accelerated carbonation products of the synthetic calcium silicate hydrate(C-S-H) by QXRD and TG/MS
Quantitative analysis of accelerated carbonation products of the synthetic calcium silicate hydrate(C-S-H) by QXRD and TG/MS
复制标题
QXRD和TG/MS定量分析合成水合硅酸钙(C-S-H)的加速碳酸化产物
DOI：
10.1007/s10973-014-4093-8
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发表时间：
2015-01-01
影响因子：
4.4
通讯作者：
Fang, Yanfeng
中科院分区：
文献类型：
--
作者：
Chang, Jun;Fang, Yanfeng
本研究合成了CaO/SiO_2比为1.5的水化硅酸钙（C-S-H），得到了纯度为93.4%的C1.27SH_（0.76）。将干燥的C-S-H在8 MPa下压实至20 mm X 20 mm X 20 mm以加速碳酸化。采用QXRD（Rietveld精修法）、增重法和TG/MS分析等手段对合成水化硅酸钙的碳化产物和碳化程度进行了表征和定量评价。在0.2MPaCO2压力下加速碳酸化2 h后，增重法测得碳酸化度为71.5%，TG/MS分析测得碳酸化度为78.0%。加速碳酸化样品中方解石、文石、球文石和非晶相同时存在，分别占33.98%、17.13%、18.74%和30.15%。两个质量损失阶段，观察碳酸钙分解。第一质量损失阶段（300-660 ℃范围）主要由文石和球文石的分解引起，并且在加速碳酸化过程中形成的方解石具有相对高的分解温度，其主要集中在660-800 ℃范围内。
In this study, calcium silicate hydrate(C-S-H) with CaO/SiO2 ratio of 1.5 target mixture is synthesized and C1.27SH0.76 with 93.4 % purity is obtained. The dried C-S-H was compacted at 8 MPa to 20 mm x 20 mm x 20 mm for accelerated carbonation. The carbonation products and carbonation degree of synthetic calcium silicate hydrate are characterized and quantitatively evaluated by QXRD (Rietveld refinement), mass gain method, and TG/MS analysis. After accelerated carbonation at 0.2 MPaCO2 pressure for 2 h, the carbonation degree from mass gain method is 71.5 %, and from TG/MS analysis is 78.0 %. Calcite, aragonite, vaterite, and amorphous phase exist simultaneously in the accelerated carbonated samples, accounting for 33.98, 17.13, 18.74, and 30.15 %, respectively. Two mass-loss stages were observed for calcium carbonate decomposition. The first mass-loss stage (300-660 degrees C range) was mainly caused by the decomposition of aragonite and vaterite, and calcite formed in the accelerated carbonation process has a relatively high decomposition temperature which is mainly centered in the 660-800 degrees C range.