本文選題：脫硫灰渣　切入點：水泥混合材　出處：《成都理工大學(xué)》2015年碩士論文

【摘要】：隨著循環(huán)流化床脫硫技術(shù)的迅速發(fā)展,產(chǎn)生的脫硫灰渣量急劇增加,我國2013年的產(chǎn)量約8000萬噸。目前,這種灰渣還主要以堆放的方式處理,資源化再利用迫在眉睫。脫硫灰渣屬燒結(jié)粘土類物質(zhì),具有火山灰活性,可以作水泥混合材來使用。水泥行業(yè)對混合材需用量大,將脫硫灰渣大量應(yīng)用于水泥混合材生產(chǎn),對于資源再利用和環(huán)境保護具有重要的意義。由于脫硫灰渣中的游離氧化鈣(f-Ca O)和SO3含量較高,將其大量用作水泥混合材時,水泥的蒸壓膨脹值較大,安定性不合格。針對這些問題,本文以茂名石化動力廠的循環(huán)流化床脫硫灰渣為研究對象,重點對脫硫灰渣的基本性質(zhì),加水量、改性劑種類、粉磨時間、消解溫度等因素對脫硫灰渣中f-Ca O的消解效果及對其微觀結(jié)構(gòu)的影響,改性脫硫灰渣配制的水泥性能和微觀結(jié)構(gòu)變化這三方面進行了研究,完成的主要工作及得出的結(jié)論如下。對脫硫灰渣的基本性質(zhì)進行了詳細研究。結(jié)果發(fā)現(xiàn),茂名石化循環(huán)流化床脫硫灰渣的微觀形貌不規(guī)則,表面粗糙且疏松多孔,顆粒的粒徑級配不合理,79.50%的粒徑≥65μm,中間粒徑(D50)達到113.67μm。總Ca O含量為23.07%,其中f-Ca O為8.49%左右,與普通粉煤灰相比,這種灰渣含有特征的礦物組分Ca SO4和Ca O。隨脫硫灰渣中SO3和f-Ca O含量增加,灰渣的自硬性強度和活性指數(shù)均先增加后減小,線性膨脹率則一直增大。對影響脫硫灰渣改性效果的因素進行了系統(tǒng)研究。實驗表明,改性過程中影響脫硫灰渣f-Ca O含量的主要因素是加水量,其次是改性劑種類、消解溫度、消解時間、粉磨時間等。當(dāng)加水量為30%時,消解1d后,f-Ca O含量降到2.81%;加入1%的以硫酸鈉為主的復(fù)合改性劑B和30%的水,在45℃條件下密閉養(yǎng)護8h后,脫硫灰渣中f-Ca O含量降到2.04%。改性后的脫硫灰渣的蒸壓膨脹值減小到2μm左右,3d自硬強度的活性值由78.28%增加到82.35%,28 d的自硬強度活性值由80.69%增加到84.89%。未改性的脫硫灰渣生成的Ca(OH)2覆蓋在灰渣的表面,呈現(xiàn)六方板狀;加入1%以硫酸鈉為主的復(fù)合改性劑B和以三乙醇胺為主的復(fù)合改性劑C,粉磨15 min后于40℃養(yǎng)護1 d,其脫硫灰渣顆粒表面生成的Ca(OH)2晶體呈簇狀向外生長,扦插在空隙之中,同時顆粒表面生成了絮狀物質(zhì),灰渣表面結(jié)構(gòu)得以改善。對脫硫灰渣配制的水泥性能和微觀結(jié)構(gòu)的變化進行了詳細考察。實驗發(fā)現(xiàn),與摻加30%未改性的脫硫灰渣水泥相比,摻加30%改性后的脫硫灰渣的水泥,水灰比從原來的0.3045降為0.285,初、終的凝結(jié)時間明顯加快,蒸壓膨脹值由0.5248 mm減小為0.2789 mm,膠砂強度后期發(fā)展明顯,抗壓活性比由7d的77.06%增加到28 d的94.01%。水泥凈漿試塊水化3 d和28 d的SEM圖和XRD譜圖表明,改性劑B改性的灰渣配制的水泥,其水化進程加快,鈣礬石形成提前,水化28 d后大塊的氫氧化鈣(CH)基本消失,水化硅酸鈣(C-S-H)凝膠與鈣礬石(AFt)的結(jié)合更加緊密,水化后的密實度明顯增加。改性后的脫硫灰渣,活性值增大,有害組分含量減少,可作為水泥混合材而大量使用。當(dāng)其摻量達到30%左右時,水泥的各項性能指標(biāo)均滿足美國材料化學(xué)學(xué)會標(biāo)準(zhǔn)(ASTM C)的要求。
[Abstract]:With the rapid development of circulating fluidized bed desulfurization technology, desulfurization ash production increased dramatically, China's 2013 production of about 80 million tons. At present, the main way to ash pile treatment, reuse is imminent. Desulfurization ash sintered clay material, with volcano activity, can be used as cement admixture the mixed material of cement industry. A large amount of desulfurization ash will need, widely used in cement production, has an important significance for the reuse of resources and environmental protection. Because of free calcium oxide in the desulfurization ash (f-Ca O) and higher SO3 content, the amount used as cement admixture, cement Autoclave Expansion larger, stability unqualified. To solve these problems, this paper takes the circulating fluidized bed desulfurization ash of Maoming petrochemical power plant as the research object, focus on the basic properties of desulfurization ash water amount, modified Agent, grinding time, digestion effect factors digestion temperature on desulfurization ash in f-Ca O and its effect on the microstructure of modified cement properties and microstructure changes of preparation of Desulfurization Residues in these three areas were studied, the main work and conclusions are as follows. On the basic properties of desulfurization ash a detailed study. The results showed that the morphology of Maoming Petrochemical circulating fluidized bed desulfurization ash is irregular and rough surface and porous particle size grading is not reasonable, 79.50% of the size of more than 65 m, middle diameter (D50) reached 113.67 M. total Ca O content is 23.07%, which is about 8.49% f-Ca O, compared with ordinary fly ash, mineral composition and features of this ash containing Ca SO4 and Ca O. with SO3 f-Ca and O content of desulfurization ash increase in ash from the rigidity strength and activity index were increased first and then decreased, linear expansion rate is always Increased. Influence factors of desulfurization ash modification effect were studied. Experimental results show that the modified process of main factors affecting the desulfurization ash content of O f-Ca is the amount of water, followed by the type of modifier, digestion temperature, digestion time, grinding time. When the water content is 30%, digestion after 1D. F-Ca O was reduced to 2.81%; adding 1% with sodium sulfate based compound modifier B and 30% water, under the condition of 45 DEG C in airtight curing 8h, the f-Ca O content of desulfurization ash dropped to 2.04%. modified desulfurization ash after Autoclave Expansion decreases to about 2 m, 3D strength activity increased from 78.28% to 82.35%, 28 d from the hard strength activity increased from 80.69% to 84.89%. is not modified desulfurization ash generative Ca (OH) 2 covered in ash surface, showing the six plate; adding 1% with sodium sulfate based compound modifier B and composites with triethanolamine based Agent C, grinding after 15 min at 40 DEG C for maintenance of 1 D, the desulfurization ash particles formed on the surface of Ca (OH) 2 Crystal clumps of outward growth, cutting in the gap, while the particles formed on the surface of flocculent material, ash can be improved. The changes of surface structure properties of cement preparation and microstructure of desulfurization ash were investigated in detail. The experimental results showed that, compared with adding 30% unmodified cement of desulfurization ash, modified desulfurization ash after adding 30% of cement, water cement ratio decreased from 0.3045 to 0.285, at the beginning of the final setting time significantly accelerated the autoclave expansion value decreases from 0.5248 mm to 0.2789 mm, the late strength development is obvious, the compressive activity ratio increased from 77.06% 7d to 28 d 94.01%. cement test block water 3 D and 28 d SEM and XRD spectra indicated that compound modifier B modified slag cement, the hydration process accelerated, ettringite formation in advance, water 2 After 8 d chunks of calcium hydroxide (CH) disappeared, calcium silicate hydrate (C-S-H) gel and Ettringite (AFt) combined with more closely, density of water after modified desulfurization ash increased significantly. After the activity increases, reduce the content of harmful components, can be used as cement admixture and a large number of use. When its content reaches about 30%, the performance index of cement can meet the American Institute of chemical materials standard (ASTM C) requirements.

【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TQ172.1

【參考文獻】

相關(guān)期刊論文 前1條

1 王志娟;侯文斌;查忠勇;;流化床燃煤固硫灰渣自硬機理的研究[J];粉煤灰;2007年04期

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本文編號：1702991