發(fā)布時(shí)間：2018-02-03 14:41

  本文關(guān)鍵詞： 水化硅酸鈣 加速碳化 顯微結(jié)構(gòu) 核磁共振　出處：《硅酸鹽學(xué)報(bào)》2015年08期 　論文類(lèi)型：期刊論文

【摘要】：廢棄水泥石等固體廢棄物碳酸化不僅能夠永久固碳,還可實(shí)現(xiàn)固體廢棄物的再利用,減少對(duì)環(huán)境的污染。水化硅酸鈣(C-S-H)是最主要的可碳化成分之一。合成了鈣硅(C/S)比為1.50的C-S-H,研究了加速碳化對(duì)其顯微結(jié)構(gòu)的影響。用Rietveld全譜擬合的方法和熱重-質(zhì)譜聯(lián)用的方法對(duì)碳化產(chǎn)物進(jìn)行定量分析,用掃描電鏡、N2吸附和29Si固體核磁共振對(duì)碳化前后的顯微結(jié)構(gòu)進(jìn)行表征。結(jié)果表明:在99.9%CO2,0.2 MPa壓力下加速碳化2 h之后,生成了3種不同晶型的碳酸鈣和硅膠,碳酸鈣從300℃開(kāi)始分解,文石和球霰石具有較低的分解溫度,結(jié)晶良好的方解石分解溫度較高;多孔結(jié)構(gòu)硅膠具有更高的吸附能力,但C-S-H碳化后的平均孔徑從10.33 nm減小到6.69 nm,比表面積由85.6 m2/g減小到67.7 m2/g,這是由于大量的結(jié)構(gòu)致密的碳酸鈣晶體堆積造成的;C-S-H雙層硅氧鏈之間的Ca O層逐漸脫去與CO2反應(yīng),硅氧四面體被質(zhì)子化或與鄰近的硅氧四面體鏈接,形成了聚合度更高的Q3和Q4結(jié)構(gòu)。
[Abstract]:Carbonation of solid waste, such as waste cement stone, can not only sequester carbon permanently, but also realize the reuse of solid waste. In order to reduce the pollution to the environment, calcium silicate hydrate (C-S-H) is one of the most important carbonable components. C-S-H with a ratio of 1.50% of calcium to silicon (C / S) has been synthesized. The effect of accelerated carbonization on microstructure was studied. The carbonation products were quantitatively analyzed by Rietveld full-spectrum fitting and thermogravimetric mass spectrometry. The microstructure before and after carbonization was characterized by N2 adsorption and 29Si solid nuclear magnetic resonance. The results showed that the carbonization was accelerated at 99.9 and CO _ 2O _ 2 MPa pressure for 2 h. Three different crystal forms of calcium carbonate and silica gel were formed. Calcium carbonate began to decompose at 300 鈩，

本文編號(hào)：1487627