本文選題：硅酸鹽水泥熟料礦物 + 吸附　； 參考：《西南科技大學(xué)》2015年碩士論文

【摘要】：水泥固化法是目前常用的固化中低放射性廢物的方法。鈾是中低放廢物的重要組成部分和長期放射性貢獻(xiàn)者。探討鈾與硅酸鹽水泥熟料礦物的相互作用為水泥固化含鈾廢物的研究提供了數(shù)據(jù)及理論研究成果。采用傳統(tǒng)的固相燒結(jié)方法,制備出四種硅酸鹽水泥熟料礦物(C3S、C2S、C3A、C4AF)。運(yùn)用“乙二醇法”測定熟料礦物中的游離氧化鈣(f-CaO)含量,采用X射線衍射儀表征熟料礦物組成。結(jié)果表明:四種熟料礦物的特征衍射峰均與其標(biāo)準(zhǔn)衍射峰匹配較好,且隨著燒結(jié)次數(shù)的增加,ω(f-CaO)不斷減少。運(yùn)用TAM air、XRD、FTIR、SEM-EDS等現(xiàn)代測試手段研究不同濃度的含鈾(Ⅵ)模擬廢液對四種熟料礦物水化的影響。結(jié)果表明:含U(Ⅵ)廢液的加入能夠促進(jìn)礦物C3S和C2S的水化,對于礦物C3A和C4AF卻是抑制作用,且隨著鈾濃度的增加,效果越明顯。對熟料礦物28d水化產(chǎn)物進(jìn)行掃描對比,發(fā)現(xiàn)含鈾廢液的存在顯著改變了熟料礦物水化產(chǎn)物的形貌。應(yīng)用靜態(tài)吸附法,研究了熟料礦物(C3S和C2S)的水化產(chǎn)物在不同的溫度、不同的初始濃度廢液中去除含鈾模擬廢液中的鈾的性能。結(jié)果表面:溫度越高,水化產(chǎn)物對鈾的去除平衡時(shí)間越短,平衡時(shí)的去除率更高。C2S水化產(chǎn)物在相同實(shí)驗(yàn)條件下比C3S水化產(chǎn)物去除鈾的效果好。當(dāng)廢液初始濃度由10mg/L增大5倍,10倍,15倍時(shí),最大去除率均在一定程度上下降。這說明熟料礦物(C3S和C2S)的水化產(chǎn)物去除含鈾模擬廢液中的鈾的過程存在一個(gè)最佳的初始濃度。采用水熱合成的方法制備出三種鈣硅比的純C-S-H凝膠與摻加鈾的C-S-H凝膠。運(yùn)用X射線衍射和紅外分析探討重金屬鈾在C-S-H凝膠的形成過程中對其結(jié)構(gòu)的影響,應(yīng)用靜態(tài)吸附法研究純C-S-H凝膠對含鈾模擬廢液中鈾的去除效果。結(jié)果表明:鈾的加入使凝膠的有序性變得較差,結(jié)晶性降低。三種鈣硅比的純C-S-H凝膠均能快速去除溶液中的U(Ⅵ),且三種鈣硅比的C-S-H凝膠最后對鈾的去除率僅相差一個(gè)百分點(diǎn)(C/S=0.8、1.3、1.8的分別為98.29%、97.05%、98.08%),說明鈣硅比對凝膠的除鈾性能影響不大。
[Abstract]:Cement curing method is a commonly used method for solidifying low-and-middle-level radioactive wastes. Uranium is an important component of low-and medium-level radioactive waste and a long-term radioactive contributor. The study on the interaction between uranium and Portland cement clinker minerals provides data and theoretical results for the study of cement solidified uranium containing waste. Four kinds of Portland cement clinker minerals, C _ 3S _ (2) C _ (2) S _ (2) C _ (3A) C _ (3A) C _ (4AFN), were prepared by conventional solid-state sintering method. The content of free calcium oxide f-CaO in clinker minerals was determined by "ethylene glycol" method, and the clinker mineral composition was characterized by X-ray diffraction instrument. The results show that the characteristic diffraction peaks of the four clinker minerals match well with their standard diffraction peaks and decrease with the increase of sintering times. The effects of different concentrations of uranium (鈪，

本文編號(hào)：1830806