摘要
以高纯度南非红柱石(有4～1mm、<1mm和<0.088mm三种粒级,且4～1mm的颗粒料为1500℃3h煅烧过的熟料)和活性氧化铝细粉(粒度<0.044mm)为原料,经配料、混练、成型、干燥后,将一部分试样分别在1300℃、1400℃、1500℃和1600℃下保温3h煅烧;另一部分试样在1600℃下分别保温1h、3h、6h和9h煅烧,待试样随炉冷却至常温后,检测其体积密度、显气孔率、耐压强度和烧成线变化率等,并采用XRD、SEM等手段分析各试样的物相组成和显微结构,以研究烧成温度及保温时间对高纯度红柱石的莫来石化程度及对红柱石基材料烧结性能的影响。结果表明:提高烧成温度对促进高纯红柱石的莫来石化十分有效,延长保温时间对于促进制品的烧结作用很大;高纯红柱石基材料需在1600℃下保温3h烧成,才能使红柱石完全莫来石化;欲使材料烧结良好且玻璃相含量低,物相较纯,则保温时间要达到6h左右。
High-purity South Africa andalusite with three particle sizes （4- 1 mm, 〈 1 mm and 〈0.088 mm） and active alumina fine powder （ 〈0. 044 mm） were used as experimental starting materials,and the coarsest （4 -1 mm） andalusite aggregate was calcined in advance at 1500 ℃ for 3 h. After being prepared via batching,mixing,forming and drying,some of specimens were fired at 1300 ℃, 1400 ℃, 1500 ℃ and 1600 ℃ with 3 h of soaking time for each temperature, respectively,whereas the others were fired at 1600 ℃ for 1 h, 3 h,6 h and 9 h, respectively. After the fired specimens were cooled to room temperature with the furnace, their bulk density, apparent porosity,cold crushing strength, heating linear change rate were measured, and phase composition and microstructure of the specimens fired under different conditions were investigated by means of XRD and SEM,so it was studied that the effects of firing temperature and soaking time on the mullitization extent of the high-purity andalusite and on the sintering property of the andalusite based refractories： The results show that enhancing firing temperature is very effectual in promoting mullitization of the high-purity andalusite,whereas prolonging soaking time is effective in improving sintering state of the high-purity andalusite based refractories. The refractories need to be fired at 1600 ℃ for 3 h so as to make the high-purity andalusite in it mullitized wholly. In order to make the refractories sintered very well and with more mullite and less glass phase,then the soaking time at 1600 ℃ should be 6 h or so.
出处
《耐火材料》
EI
CAS
北大核心
2005年第4期255-258,共4页
Refractories
