本文選題：添加造孔劑法 + 毛細(xì)管漿料法��； 參考：《安徽建筑大學(xué)》2015年碩士論文

【摘要】：煤矸石是我國(guó)最大宗的工業(yè)固體廢棄物,長(zhǎng)期的露天堆積導(dǎo)致大量土地被占?jí)?污染了水體、土壤和大氣,對(duì)礦區(qū)的環(huán)境造成嚴(yán)重的危害,影響了人們的生命健康。隨著科技的進(jìn)步,煤矸石的綜合利用有了較大的發(fā)展,應(yīng)用范圍不斷擴(kuò)大。通過(guò)對(duì)煤矸石中化學(xué)成分分析發(fā)現(xiàn),其中主要的成份氧化硅和氧化鋁與制備陶瓷的原材料相近,因此以煤矸石為原料制備多孔陶瓷,成為煤矸石資源化利用的新途徑。多孔陶瓷是一種利用其孔隙結(jié)構(gòu)獲得優(yōu)異的物理性能和力學(xué)性能的功能結(jié)構(gòu)一體化材料,由于具有較高的顯氣孔率、均勻分布的微孔、有發(fā)達(dá)的比表面體積、耐高溫、耐高壓等優(yōu)點(diǎn),廣泛應(yīng)用于航空航天,醫(yī)學(xué)、環(huán)保、建筑、石油化工等行業(yè),在科學(xué)技術(shù)領(lǐng)域和國(guó)民建設(shè)中發(fā)揮這巨大作用。本文以淮南礦區(qū)煤矸石為主要原料,懫用添加造孔劑法和毛細(xì)管漿料法制備出了高氣孔率、高強(qiáng)度的多孔陶瓷材料。主要研究了煤矸石的酸浸處理、燒成溫度、保溫時(shí)間、添加劑含量、莫來(lái)石纖維的添加量以及漿料的固相含量等對(duì)多孔陶瓷顯氣孔率、抗壓強(qiáng)度、顯微結(jié)構(gòu)及物相等的影響。研究結(jié)果如下:1.制備陶瓷之前,研究了煤矸石原料的酸浸處理和煤矸石漿料的流變特性。(1)采用酸浸法對(duì)煤矸石的雜質(zhì)含量進(jìn)行控制,通過(guò)除鐵率來(lái)表征雜質(zhì)去除的效果。除鐵率隨著混酸濃度的增加而提高,當(dāng)混酸濃度為5%HCl+21%H2SO4時(shí),除鐵率達(dá)到68.32%;之后,隨著濃度的增加,除鐵率幾乎不再發(fā)生變化;(2)通過(guò)調(diào)節(jié)pH值和分散劑的添加量來(lái)獲得高固相含量、低粘度的陶瓷漿料,隨著pH值和分散劑含量的增加,漿料Zeta電位的絕對(duì)值呈先增大后減少的趨勢(shì),當(dāng)pH值為10,聚羧酸分散劑的含量為0.1%時(shí),Zeta電位的絕對(duì)值達(dá)到最大值56.75mV,此時(shí),漿料的穩(wěn)定性最好。2.采用添加造孔劑法制備多孔陶瓷,研究了以煤矸石中所含有的有機(jī)質(zhì)為造孔劑制備多孔陶瓷的燒結(jié)工藝;再添加淀粉造孔劑進(jìn)一步提高多孔陶瓷的顯氣孔率;并利用莫來(lái)石纖維改善了多孔陶瓷的高溫收縮特性;最后以煤矸石為主要原料,配以適量氧化鋁和氧化鎂,低溫制備了堇青石多孔陶瓷。(1)以煤矸石中所含有的有機(jī)質(zhì)為造孔劑制備多孔陶瓷:對(duì)比了未經(jīng)酸浸處理和酸處理后的煤矸石原料的燒結(jié)特性,隨著燒結(jié)溫度從1050℃升高到1300℃,酸處理煤矸石多孔陶瓷的抗壓強(qiáng)度隨燒結(jié)溫度的升高由12.75 MPa增加到141.3MPa、顯氣孔率則由40.87%下降到9.21%;而未經(jīng)酸處理的煤矸石多孔陶瓷,其抗壓強(qiáng)度由31.60MPa增加至84.35 MPa(1250℃)后減小到50.10MPa,孔隙率則由35.72%下降到0.21%后增加到3.35%。這是由于煤矸石中的雜質(zhì)在低溫?zé)Y(jié)時(shí)易形成固溶體活化晶格并產(chǎn)生液相,促進(jìn)了燒結(jié)反應(yīng)的進(jìn)行。但是雜質(zhì)含量過(guò)多時(shí),在高溫?zé)Y(jié)時(shí)易產(chǎn)生大量的玻璃相和氣泡,導(dǎo)致多孔陶瓷抗壓強(qiáng)度急劇下降而顯氣孔率在降低到一定值后有所增加,因此必須采用有效的手段來(lái)控制煤矸石中的雜質(zhì)含量。(2)以酸處理的煤矸石為原料制備出的多孔陶瓷顯氣孔率在50%以下,本文通過(guò)添加造孔劑的方法來(lái)進(jìn)一步提高其顯氣孔率。1200℃煅燒后,添加60%的淀粉造孔劑可使多孔陶瓷的顯氣孔率由不加造孔劑時(shí)的24.55%增加到51.57%,此時(shí)多孔陶瓷的抗壓強(qiáng)度為17.44mpa;并且隨著造孔劑的含量由40%增加到70%,顯氣孔率由44.16%增加到55.54%。由此可見(jiàn),添加造孔劑可顯著提高多孔陶瓷的顯氣孔率。(3)為了改善多孔陶瓷的高溫收縮性能,本文通過(guò)添加莫來(lái)石纖維來(lái)降低其高溫?zé)Y(jié)線性收縮率。在高溫?zé)Y(jié)過(guò)程中,隨著燒結(jié)溫度的增加,燒成收縮率逐漸增加,在1250℃時(shí),燒成線性收縮率達(dá)到14.22%,顯氣孔率僅為48.57%,而當(dāng)添加30%的莫來(lái)石纖維時(shí),燒成線性收縮率僅為2.22%,此時(shí)的顯氣孔率達(dá)到65.62%。由此可見(jiàn),莫來(lái)石纖維可有效降低多孔陶瓷的燒成收縮率,提高其顯氣孔率。(4)以煤矸石為原料,通過(guò)對(duì)多孔陶瓷孔隙結(jié)構(gòu)和機(jī)械性能的調(diào)節(jié)以及對(duì)其制備工藝的探索研究,制備除了高孔隙率、高強(qiáng)度的多孔陶瓷,為了進(jìn)一步提高煤矸石的資源化利用水平,通過(guò)配以適量氧化鋁和氧化鎂,在低溫條件下制備出了具有低熱膨脹系數(shù)和優(yōu)良熱振穩(wěn)定性的堇青石多孔陶瓷。在燒結(jié)溫度達(dá)到1200℃時(shí),堇青石相開(kāi)始出現(xiàn),隨著燒結(jié)溫度和保溫時(shí)間的增加,堇青石的含量逐漸增加,當(dāng)溫度達(dá)到1225℃,即可得到純度較高的堇青石多孔陶瓷。相比于采用其他的原料制備的堇青石多孔陶瓷,其燒結(jié)溫度降低了約100℃。3.為了進(jìn)一步探索減少多孔陶瓷在干燥和燒成過(guò)程中收縮的工藝條件,本文探討了一種新型的多孔陶瓷制備方法,即毛細(xì)管漿料法。先利用純度較高的石英砂為原料,探索毛細(xì)管漿料法制備多孔陶瓷的工藝,然后利用此方法制備煤矸石多孔陶瓷。(1)以石英砂為原料,探討助燒劑對(duì)多孔陶瓷燒結(jié)性能的影響,結(jié)果表明,助燒劑可以顯著改善多孔陶瓷的燒結(jié)性能,并且三元助燒劑的效果優(yōu)于二元系統(tǒng)。在不加助燒劑的情況下,1610℃時(shí),多孔陶瓷的顯氣孔率為55.82%,而抗壓強(qiáng)度為僅為0.83mpa,而添加(5%cao+3%al2o3+2%mgo)混合料為助燒劑,在1370℃時(shí),多孔陶瓷的顯氣孔率和抗壓強(qiáng)度分別達(dá)到40.14%和4.48mpa,極大的降低了燒成溫度。(2)以煤矸石為原料,以過(guò)0.075mm方孔篩的細(xì)煤矸石和5%cao+3%al2o3+2%mgo混合料為助燒劑,在不同燒結(jié)溫度的作用下,考察顯氣孔率和抗壓強(qiáng)度的變化,結(jié)果表明5%cao+3%al2o3+2%mgo混合料的助燒效果明顯優(yōu)于細(xì)煤矸石,以混合料為助燒劑、1250℃燒結(jié)的樣品,其抗壓強(qiáng)度和顯氣孔率分別為20.71mpa和34.97%,而添加細(xì)煤矸石的樣品,抗壓強(qiáng)度和顯氣孔率分別為為0.75MPa和50.75%。但進(jìn)一步增加助燒劑含量,對(duì)于提高燒結(jié)性能效果并不明顯。
[Abstract]:Coal gangue is the most important industrial solid waste in China. A long period of open pit accumulation has caused a large amount of land to be pressed, polluting the water, soil and atmosphere, causing serious harm to the environment of the mining area and affecting people's life and health. With the progress of science and technology, the comprehensive utilization of coal gangue has been greatly developed and the application scope is expanding continuously. Through the analysis of the chemical composition in the gangue, it is found that the main components of the silica and alumina are similar to the raw materials prepared. Therefore, the preparation of porous ceramics with coal gangue as raw material has become a new way for the utilization of coal gangue. Porous ceramics are a kind of excellent physical and mechanical properties by using its pore structure. The functional structure integrated materials have been widely used in aerospace, medical, environmental, construction, petrochemical and other industries because of the advantages of high porosity, uniform distribution of micropores, developed specific surface volume, high temperature resistance and high pressure resistance, which play a great role in the field of science and technology and national construction. This paper is based on coal mining in Huainan mining area. High porosity and high strength porous ceramic materials are prepared by adding hole agent method and capillary slurry method. The main research is the acid leaching of coal gangue, sintering temperature, heat preservation time, additive content, adding amount of mullite fiber and solid content of slurry to porous ceramics. The results are as follows: 1. before preparing the ceramics, the acid leaching of the gangue raw materials and the rheological properties of the coal gangue slurry were studied. (1) the impurity content of the gangue was controlled by acid leaching, and the removal efficiency of the impurity was characterized by the iron removal rate. The iron removal rate was raised with the increase of the mixed acid concentration. High, when the concentration of mixed acid is 5%HCl+21%H2SO4, the iron removal rate is 68.32%. After the increase of the concentration, the iron removal rate is almost no longer changed. (2) the high solid content is obtained by adjusting the pH value and the addition of dispersant. With the increase of the pH value and the dispersant content, the absolute value of the Zeta potential of the slurry is increased first. After the decreasing trend, when the pH value is 10 and the content of polycarboxylic acid dispersant is 0.1%, the absolute value of Zeta potential reaches the maximum value 56.75mV. At this time, the best stability of the slurry is to prepare porous ceramics by adding pore forming agent, and study the sintering process of preparing porous ceramics by the organic matter contained in the gangue, and then adding starch. The porosity of porous ceramics is further improved and the high temperature shrinkage characteristics of porous ceramics are improved by using mullite fiber. At the end, the porous ceramics of cordierite are prepared at low temperature with the coal gangue as the main raw material, with a proper amount of alumina and Magnesium Oxide. (1) the porous ceramics are prepared by the organic matter in the gangue. Compared with the sintering characteristics of coal gangue raw materials without acid treatment and acid treatment, with the sintering temperature rising from 1050 to 1300, the compressive strength of the acid treated coal gangue porous ceramics increased from 12.75 MPa to 141.3MPa with the increase of sintering temperature, and the apparent porosity decreased from 40.87% to 9.21%; and the untreated coal gangue porous ceramics, The compressive strength is increased from 31.60MPa to 84.35 MPa (1250 C) to 50.10MPa, and the porosity is decreased from 35.72% to 0.21% to 3.35%., which is due to the impurities in the coal gangue which can easily form the solid solution activation lattice and produce the liquid phase at low temperature sintering, and promote the sintering reaction. But the impurity content is too high at high temperature. It is easy to produce a large number of glass and bubbles, resulting in a sharp decline in the compressive strength of porous ceramics and an increase in the apparent porosity after reducing to a certain value. Therefore, effective means must be used to control the content of impurities in the gangue. (2) the porosity of porous ceramics prepared from the coal gangue treated with acid is less than 50%. After adding the pore forming agent to further improve its apparent porosity.1200 C calcinations, adding 60% of the starch pore forming agent can increase the apparent porosity of porous ceramics from 24.55% to 51.57% when the porosity is not added, and the compressive strength of the porous ceramics is 17.44mpa, and with the increase of pore forming agent from 40% to 70%, the apparent porosity is 44.16%. The increase to 55.54%. shows that the porosity of porous ceramics can be significantly increased by adding pore making agents. (3) in order to improve the high temperature shrinkage of porous ceramics, the linear shrinkage rate of high temperature sintering is reduced by adding mullite fiber. In the process of high temperature sintering, the sintering shrinkage rate increases with the increase of sintering temperature, at 1250. At C, the linear shrinkage rate was 14.22% and the apparent porosity was only 48.57%. When the 30% mullite fiber was added, the linear shrinkage rate was only 2.22%. The apparent porosity reached 65.62%., and the mullite fiber could effectively reduce the sintering shrinkage of porous ceramics and increase the apparent porosity. (4) coal gangue was used as the raw material. In order to further improve the resource utilization level of coal gangue, in order to further improve the utilization level of coal gangue, the low thermal expansion coefficient and good quality are prepared under low temperature conditions in order to further improve the utilization level of coal gangue in order to further improve the utilization level of the coal gangue, in order to improve the porous and high strength porous ceramics. Cordierite porous ceramics with hot vibration stability are formed when the sintering temperature reaches 1200 degrees C. The cordierite content increases with the increase of sintering temperature and holding time. When the temperature reaches 1225, the cordierite porous ceramics with higher purity can be obtained. Compared to the cordierite porous materials prepared with other raw materials, the cordierite porous ceramics can be obtained. In order to further explore the technological conditions for reducing the shrinkage of porous ceramics during drying and firing process, the sintering temperature of ceramics was reduced by about 100.3.. A new method of preparation of porous ceramics, namely, capillary slurry method, was discussed in this paper. This method is used to prepare the coal gangue porous ceramics. (1) the effect of sintering aid on the sintering properties of porous ceramics is investigated with quartz sand as raw material. The results show that the sintering agent can significantly improve the sintering properties of porous ceramics, and the effect of three element burning AIDS is superior to two yuan system. Under the condition of no burning AIDS, more Kong Tao at 1610. The apparent porosity of porcelain is 55.82%, while the compressive strength is only 0.83mpa, and the addition of (5%cao+3%al2o3+2%mgo) mixture is a burning AIDS. At 1370, the apparent porosity and the compressive strength of the porous ceramics are 40.14% and 4.48mpa, respectively, and the sintering temperature is greatly reduced. (2) the gangue and 5%cao+ with the coal gangue as the raw material and the 0.075mm square hole sieve. 3%al2o3+2%mgo mixture was used as a sintering aid. The changes of apparent porosity and compressive strength were investigated under different sintering temperatures. The results showed that the burning effect of 5%cao+3%al2o3+2%mgo mixture was obviously better than that of fine coal gangue, and the mixture was used as a sintering aid. The compressive strength and the apparent porosity of the samples sintered at 1250 C were 20.71mpa and 34.97% respectively. With the addition of fine coal gangue, the compressive strength and the apparent porosity are 0.75MPa and 50.75%. respectively, but further increase the content of the burning agent, and the effect of increasing the sintering performance is not obvious.

【學(xué)位授予單位】：安徽建筑大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TQ174.7

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本文編號(hào)：1811212