化工学报
化工學報
화공학보
JOURNAL OF CHEMICAL INDUSY AND ENGINEERING (CHINA)
2014年
2期
576-582
,共7页
李歌%李增和%马鸿文%陈登利
李歌%李增和%馬鴻文%陳登利
리가%리증화%마홍문%진등리
纳米氢氧化镁%热重分析%热分解%动力学%纳米氧化镁
納米氫氧化鎂%熱重分析%熱分解%動力學%納米氧化鎂
납미경양화미%열중분석%열분해%동역학%납미양화미
nano-magnesium hydroxide%thermal gravimetric analysis%thermal decomposition%kinetics%nano-magnesium oxide
以白云石为原料,盐酸酸溶后得到CaCl2-MgCl2滤液,采用氨水直接沉淀法制备出符合HG/T 3607-2000Ⅰ型标准的六方片状的纳米氢氧化镁。六方片厚度为25~30 nm,直径为0.3~0.4μm。利用热重分析法对纳米氢氧化镁在不同升温速率下的热分解动力学进行研究,以期深入了解纳米氢氧化镁热分解制备纳米氧化镁粉体过程的物理化学本质。采用Kissinger法和Ozawa法计算出氢氧化镁热分解反应活化能分别为115.47 kJ·mol-1和126.04 kJ·mol-1。对热重分析数据进行处理和拟合,判断纳米氢氧化镁粉体热分解反应机理函数为Avrami-Erofeev(n=1.5)的随机成核和随后生长机理。指前因子为3.077×1010 s-1。纳米氢氧化镁经煅烧制备得到的氧化镁纳米球的直径为80~100 nm。
以白雲石為原料,鹽痠痠溶後得到CaCl2-MgCl2濾液,採用氨水直接沉澱法製備齣符閤HG/T 3607-2000Ⅰ型標準的六方片狀的納米氫氧化鎂。六方片厚度為25~30 nm,直徑為0.3~0.4μm。利用熱重分析法對納米氫氧化鎂在不同升溫速率下的熱分解動力學進行研究,以期深入瞭解納米氫氧化鎂熱分解製備納米氧化鎂粉體過程的物理化學本質。採用Kissinger法和Ozawa法計算齣氫氧化鎂熱分解反應活化能分彆為115.47 kJ·mol-1和126.04 kJ·mol-1。對熱重分析數據進行處理和擬閤,判斷納米氫氧化鎂粉體熱分解反應機理函數為Avrami-Erofeev(n=1.5)的隨機成覈和隨後生長機理。指前因子為3.077×1010 s-1。納米氫氧化鎂經煅燒製備得到的氧化鎂納米毬的直徑為80~100 nm。
이백운석위원료,염산산용후득도CaCl2-MgCl2려액,채용안수직접침정법제비출부합HG/T 3607-2000Ⅰ형표준적륙방편상적납미경양화미。륙방편후도위25~30 nm,직경위0.3~0.4μm。이용열중분석법대납미경양화미재불동승온속솔하적열분해동역학진행연구,이기심입료해납미경양화미열분해제비납미양화미분체과정적물이화학본질。채용Kissinger법화Ozawa법계산출경양화미열분해반응활화능분별위115.47 kJ·mol-1화126.04 kJ·mol-1。대열중분석수거진행처리화의합,판단납미경양화미분체열분해반응궤리함수위Avrami-Erofeev(n=1.5)적수궤성핵화수후생장궤리。지전인자위3.077×1010 s-1。납미경양화미경단소제비득도적양화미납미구적직경위80~100 nm。
Hexagonal nano-magnesium hydroxide with thickness of 25-30 nm and diameter of 0.3-0.4 μm was synthesized via acid immersion and ammonia precipitation from dolomites. Its quality met the standards of typeⅠin HG/ T 3607-2000. The thermal decomposition kinetics of Mg(OH)2 was investigated by using thermal gravimetric analysis at different heating rates for deep understanding of physical chemistry in this process. The activation energies of decomposition estimated by the Kissinger and Ozawa methods were 115.47 kJ?mol-1 and 126.04 kJ?mol-1 respectively. Decomposition reaction of magnesium hydroxide was controlled by Avrami-Erofeev function (n=1.5). Pre-exponential was 3.077×1010 s-1. Nano-magnesium oxide with average diameter of 80-100 nm was prepared after calcination of magnesium hydroxide.