本文選題：水熱合成 + 低溫煅燒　； 參考：《江蘇大學(xué)》2017年碩士論文

【摘要】：本文分別以煤矸石和鋼渣等工業(yè)廢渣為主要原料,研究了CaO-SiO_2-Al_2O_3-SO_3-Fe_2O_3系統(tǒng)中的高鐵、低鐵和無鐵三種體系,采用水熱合成-低溫煅燒新工藝,制備硫鋁酸鈣水泥熟料。通過X射線衍射分析水熱合成產(chǎn)物、水泥熟料礦物和水化產(chǎn)物,掃描電子顯微鏡觀察了水化試樣的微觀形貌,測定了熟料的f-CaO含量和硬化漿體的抗壓強(qiáng)度、化學(xué)結(jié)合水含量和Ca(OH)2含量。研究了水熱溫度對水熱前驅(qū)體組成的影響,結(jié)果表明:CaO-SiO_2-Al_2O_3-SO_3體系中,80℃水熱前驅(qū)體的主要組成為Ca6Al_2(OH)12(SO_4)3·26H2O和Ca(OH)2,以及CSH凝膠;CaO-Si O_2-Al_2O_3-SO_3-Fe_2O_3(低鐵)體系中,95℃水熱前驅(qū)體的組成為AFt(Ca6Al_2(OH)12(SO_4)3·26H2O、Ca6Fe_2(OH)12(SO_4)3·26H2O)、水化石榴石(Ca3Al_2(SiO_4)(OH)8、Ca3Al Fe(SiO_4)(OH)8)、AFm(Ca4Al_2SO10·12H2O、Ca4Fe_2SO10·12H2O)、Ca(OH)2和大量CSH凝膠;CaO-Si O_2-Al_2O_3-SO_3-Fe_2O_3(高鐵)體系中,130℃水熱前驅(qū)體的組成為AFm、水化石榴石和CSH(I)。研究了煅燒溫度對煅燒試樣礦相的影響,結(jié)果表明,在CaO-SiO_2-Al_2O_3-SO_3體系和CaO-SiO_2-Al_2O_3-SO_3-Fe_2O_3(低鐵)體系中,當(dāng)煅燒溫度為900~1100℃時,煅燒試樣的主礦相為C5S2$、β-C2S、CaSO_4、CaO和C12A7,有少量的硫鋁酸鈣;在CaO-SiO_2-Al_2O_3-SO_3-Fe_2O_3(高鐵)體系中,750℃時,煅燒試樣中主相為CaSO_4、C5S2$、C12A7和CaO,及少量的C4A3$、C4A3-x Fx$和β-C2S,煅燒溫度為950℃時,C4A3$、C4A3-xFx$和β-C2S的生成量增加,煅燒溫度為1050℃時,主相為C4A3$、C4A3-xFx$和β-C2S。研究了石膏摻量對CaO-SiO_2-Al_2O_3-SO_3-Fe_2O_3(高鐵)體系(分別以礦渣和煅燒煤矸石為主要原料)水泥力學(xué)性能的影響,結(jié)果表明:適量石膏與硫鋁酸鈣水化形成三硫型水化硫鋁酸鈣,當(dāng)石膏摻量為13%時,水泥1 d的抗壓強(qiáng)度分別比同齡期熟料的抗壓強(qiáng)度增加了31.6%和28.9%;28 d抗壓強(qiáng)度分別比同齡期熟料的抗壓強(qiáng)度增加了64.7%和57%。通過掃描電鏡觀察水泥試樣水化28 d后水化產(chǎn)物的形貌,可看到大量的CSH凝膠,AFt生長完整,呈長纖狀,長徑比可達(dá)到200~300,彼此交錯,構(gòu)成網(wǎng)狀組織。在CaO-SiO_2-Al_2O_3-SO_3-Fe_2O_3(高鐵)體系的硫鋁酸鈣水泥熟料煅燒過程中,130℃水熱前驅(qū)體的組成主要為AFm、水化石榴石和CSH(I),受熱時逐步脫去水熱產(chǎn)物的自由水、層間水和結(jié)合水,首先AFm脫水為無水C3A·CaSO_4,水化石榴石脫水生成C12A7、Ca(OH)2和SiO_2,CSH(I)分解生成β-C2S;接著溫度繼續(xù)升高,Ca(OH)2脫去結(jié)合水生成的CaO,無水AFm分解生成C12A7、CaSO_4和CaO,CaSO_4和β-C2S反應(yīng)生成C5S2$,C5S2$在較高溫下會分解;最后,CaO與SiO_2生成β-C2S,C12A7、CaSO_4生成C4A3$,Fe部分取代Al形成C4A3-xFx$。由于750℃時出現(xiàn)大量中間相,1050℃即可基本完全合成硫鋁酸鈣水泥礦物,致使水泥熟料合成溫度低于常見的硫鋁酸鹽礦物150~250℃。
[Abstract]:In this paper, using industrial waste such as coal gangue and steel slag as main raw materials, three systems of high iron, low iron and no iron in CaO-SiO _ 2-Al _ 2O _ 3-so _ 3-Fe _ 2O _ 3 system were studied to prepare calcium sulphoaluminate cement clinker by hydrothermal synthesis and low temperature calcinations. The hydrothermal synthesis products, cement clinker minerals and hydration products were analyzed by X-ray diffraction. The microstructure of hydrated samples was observed by scanning electron microscope. The f-CaO content of clinker and the compressive strength of hardened slurry were measured. The contents of chemically bound water and CaOH2. The effect of hydrothermal temperature on the composition of hydrothermal precursors was studied. 緇撴灉琛ㄦ槑:CaO-SiO_2-Al_2O_3-SO_3浣撶郴涓，

本文編號：2023936