本文選題：高鈣鎂鈣耐火材料　切入點(diǎn)：活性MgO　出處：《西安建筑科技大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：近年來,隨著潔凈鋼、特種鋼等高端鋼鐵產(chǎn)品的生產(chǎn)需要,MgO-Ca O質(zhì)耐火材料的生產(chǎn)和研究日益受到國內(nèi)外的重視,該耐火材料具有耐火度高、堿度高、抗渣性好、耐剝落性強(qiáng)等特點(diǎn),特別是其內(nèi)部的游離CaO具有良好的凈化鋼水作用,是冶煉潔凈鋼、特種鋼等不可或缺的優(yōu)質(zhì)耐火材料,具有廣泛的應(yīng)用前景。但是MgO-CaO質(zhì)耐火材料最大的缺點(diǎn)是CaO在空氣中極易發(fā)生水化反應(yīng),造成材料粉化,使其應(yīng)用受到了極大限制。國內(nèi)外很多學(xué)者對MgO-CaO質(zhì)耐火材料的抗水化性能做過研究,方法包括二步煅燒法、引入添加劑、表面處理等多種方式,本課題的研究方向主要是通過二步煅燒法和引入Fe2O3+ZrO2復(fù)合添加劑兩種方式,來提高M(jìn)gO-CaO質(zhì)耐火材料的抗水化性能。本課題研究主要包括三步:第一步,以天然白云石礦和天然菱鎂礦為原料,破碎磨細(xì)至粒度小于100μm,分別在不同溫度下輕燒、保溫2h,制得MgO、CaO粉料,經(jīng)過活性測試分別選取活性最高的輕燒溫度。第二步,將兩種在活性最高溫度下輕燒后的粉料分別按照w(CaO)=45%、w(CaO)=50%、w(CaO)=55%進(jìn)行配比,之后向其中引入不同配比的Fe2O3+ZrO2復(fù)合添加劑,復(fù)合添加劑中Fe2O3、ZrO2的質(zhì)量比分別為0.5%Fe2O3+1%ZrO2、0.75%Fe2O3+2%ZrO2、1%Fe2O3+3%ZrO2,最后加入磷酸二氫鋁粉末作為結(jié)合劑,干混6h,在100MPa壓制成Φ50mm×50mm的圓柱試樣,分別于1500℃×3h和1600℃×3h燒成。第三步,根據(jù)燒后試樣的顯氣孔率、體積密度、水化增重率以及試樣的微觀結(jié)構(gòu),確定添加劑的最佳引入量。結(jié)果表明:(1)所用白云石礦的最佳輕燒溫度為1100℃,菱鎂礦的最佳輕燒溫度為800℃。(2)加入一定量活性MgO的試樣在燒結(jié)性能、抗水化性能方面優(yōu)于不加入活性MgO的試樣。(3)Fe2O3+ZrO2復(fù)合添加劑在高溫下能夠促進(jìn)MgO-西安建筑科技大學(xué)碩士學(xué)位論文CaO質(zhì)耐火材料燒結(jié)性能的提高,促進(jìn)晶粒的生長,引入復(fù)合添加劑試樣的顯氣孔率、體積密度和抗水化性能都明顯優(yōu)于不加添加劑的空白試樣,其中w(CaO)=50%、引入添加劑比例為1%Fe2O3+3%ZrO2的試樣,1600℃燒成后水化率從空白試樣的10.8%降至4.3%,說明添加劑的引入能夠有效改善MgO-CaO質(zhì)耐火材料的易水化性。(4)1600℃下燒成試樣的燒結(jié)性能、抗水化性能明顯優(yōu)于1500℃下燒成試樣,說明燒成溫度越高,對于MgO-CaO質(zhì)耐火材料燒結(jié)性能的提升越明顯,有利于抗水化性能的提高。
[Abstract]:In recent years, more and more attention has been paid to the production and research of MgO-CaO refractories for high grade steel products such as clean steel and special steel. The refractories have high fire resistance, high alkalinity and good slag resistance. It has the characteristics of strong peeling resistance, especially its internal free CaO has a good effect on purifying molten steel, and it is an indispensable and high quality refractory material for smelting clean steel and special steel, etc. However, the biggest disadvantage of MgO-CaO refractories is that CaO easily occurs hydration reaction in air, resulting in material pulverization. Many scholars at home and abroad have studied the hydration resistance of MgO-CaO refractories, which include two-step calcinations, additives, surface treatment, etc. The research direction of this subject is mainly to improve the hydration resistance of MgO-CaO refractories by two ways of two-step calcination and the introduction of Fe2O3 ZrO2 compound additive. This research mainly includes three steps: the first step is to improve the hydration resistance of MgO-CaO refractories. Using natural dolomite and natural magnesite as raw materials, the powder of MgO-CaO was prepared by crushing and grinding to less than 100 渭 m at different temperatures for 2 h, respectively. The highest light firing temperature was selected after activity test. The two kinds of powdered materials after light burning at the highest active temperature were mixed with 55% Fe2O3 ZrO2, respectively, according to the composition of 45% of the powder, and then different proportions of Fe2O3 ZrO2 compound additives were introduced into the mixture. The mass ratios of Fe _ 2O _ 3 and ZrO _ 2 in the composite additive were 0.52O3 1and 0.752O3, respectively. Finally, aluminum dihydrogen phosphate powder was added as binder, dried for 6h, compacted into 桅 50mm 脳 50mm cylindrical specimen at 100MPa, and burned at 1500 鈩，

本文編號：1641348