以TG-DSC和TG-FTIR联用,研究了轻质MgO在不同实验条件下的水化性质和水化产物.结果表明,900 ℃煅烧的MgO在室温下容易发生水化,温度升高可显著加快MgO的水化速率.常压高湿条件下,1300 ℃煅烧MgO的水化和碳酸化作用同时进行,产物为六方Mg(OH)_2和无定型的碳酸化产物,两类产物的生成量随养护温度升高而显著增加,生成的碳酸化产物的热解温度在300～450 ℃范围内,基本覆盖了Mg(OH)_2 的热分解温度范围.高于1300 ℃煅烧的MgO有较强的稳定性,室温下几乎不发生反应,但温度提高到40 ℃以上时,水化和碳酸化作用又显著进行.
Hydration properties and hydration products of light magnesium oxide were investigated under different experimental conditions by means of TG-DSC and TG-FTIR. The results show that magnesium oxide calcinated at 900 ℃ tends to hydrate even at ambient temperature. Hydration can be significantly accelerated with increasing temperature. Under the atmospheric pressure and high humidity, hydration and carbonation were both exist when MgO was calcinated at 1300 ℃. The productions of reaction are hexagonally Mg(OH)_2 and amorphous carbonate. Production quantities of these two kinds of product increase obviously along with rising of curing temperature. Pyrolysis temperature of the carbonate generating in this experiment is within 300-450 ℃, which almost covering up the range of decomposition temperature of hexagonal Mg(OH)_2. After calcinated at higher than 1300 ℃, MgO has a great stability that it hardly react with H_2O or CO_2 at room temperature. But it still tends to hydrate and carbonate when curing temperature rises up to 40 ℃ or higher.
参考文献
| [1] | 贾琳蔚,李晓云,丘泰,倪灿.氧化镁-碳化硅复相陶瓷在X波段的衰减性能[J].硅酸盐学报,2009(03):397-402. |
| [2] | 杨春霞,周洪庆,刘敏,吴红忠,梁斌斌,金宇龙.BSTO/MgO铁电移相材料的研究[J].电子元件与材料,2005(02):13-15. |
| [3] | 陶绍平,钟香崇.MgO基和Al2O3基耐火材料对钢中S的影响[J].硅酸盐通报,2006(02):105-108. |
| [4] | 李德臣.制镁还原罐的研制[J].铸造技术,2002(02):124-128. |
| [5] | 崔鑫,邓敏.氧化镁制备方法、活性与水化测定方法综述[J].硅酸盐通报,2008(01):136-141. |
| [6] | E. Soudée;J. Péra .Mechanism of setting reaction in magnesia-phosphate cements[J].Cement and Concrete Research,2000(2):315-321. |
| [7] | Mucahit Sutcu;Sedat Akkurt;Salih Okur .Influence of crystallographic orientation on hydration of MgO single crystals[J].CERAMICS INTERNATIONAL,2009(7):2571-2576. |
| [8] | 高培伟,吴胜兴,林萍华,吴中如,唐明述.氧化镁在不同养护条件下水化产物的形貌分析[J].无机化学学报,2007(06):1063-1068. |
| [9] | Rafael Salomao;Victor C. Pandolfelli .Magnesia sinter hydration-dehydration behavior in refractory castables[J].Ceramics International,2008(8):1829-1834. |
| [10] | H. Aygul Yeprem .Effect of iron oxide addition on the hydration resistance and bulk density of doloma[J].Journal of the European Ceramic Society,2007(2/3):1651-1655. |
| [11] | Y. Kato .Durability characteristics of the hydration of magnesium oxide under repetitive reaction[J].Journal of Materials Science,1999(3):475-480. |
| [12] | van der Merwe EM;Strydom CA .Hydration of medium reactive magnesium oxide using hydration agents[J].Journal of thermal analysis and calorimetry,2006(2):467-471. |
| [13] | 孙世清;谢维章 .用热分析方法研究MgO的活性[J].硅酸盐学报,1986,14(02):226-230. |
| [14] | Xiong YL;Lord AS .Experimental investigations of the reaction path in the MgO-CO2-H2O system in solutions with various ionic strengths, and their applications to nuclear waste isolation[J].Applied Geochemistry: Journal of the International Association of Geochemistry and Cosmochemistry,2008(6):1634-1659. |
| [15] | 李环,苏莉,于景坤.利用菱镁矿制备高活性氧化镁[J].耐火材料,2006(04):294-296. |
| [16] | 代厚全.轻质碳酸镁分解反应及其分子组成研究[J].四川师范大学学报(自然科学版),1998(05):545-548. |
| [17] | 王春迎,杜志明,丛晓民,田秀丽.碱式碳酸镁的热分解研究[J].应用化工,2008(06):657-660. |
| [18] | 钱海燕,邓敏,张少明.菱镁矿煅烧活性氧化镁实验研究[J].非金属矿,2004(06):1-2. |
| [19] | 唐小丽,刘昌胜.重烧氧化镁粉的活性测定[J].华东理工大学学报(自然科学版),2001(02):157-160. |
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