煅烧高岭土的比表面积与吸油性能  

Specific Surface Area and Oil Adsorption of Calcinated Kaolin Clay

作　　者：孙涛[1] 陈洁渝[1,2] 周春宇[1] 雷新荣[1] 

机构地区：[1]中国地质大学材料与化学学院,武汉430074 [2]教育部纳米矿物材料及应用工程研究中心,武汉430074

出　　处：《硅酸盐学报》2013年第5期685-690,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(41102025);教育部纳米矿物材料及应用工程研究中心开放基金(CUGNGM20132)项目

摘　　要：以水洗高岭土为原料,在600～1000℃,以50℃为间隔取点煅烧。通过场发射扫描电镜观察产品的微观形貌、X射线衍射仪分析产品的物相,并用BET物理吸附仪表征产品的比表面积和孔径分布,根据煅烧高岭土的微观形貌、物相组成、吸脱附等温线等,分析其比表面积与吸油性能的关系。结果表明:750℃的煅烧高岭土吸油值最高,为80.272g/100g,此时煅烧高岭土的比表面积最大,孔径分布集中于微孔和中孔,平均孔径最小。煅烧温度低于800℃时,煅烧高岭土的孔径分布较集中于微孔和中孔,比表面积较大,吸油值较高;煅烧温度升高至800℃以后,高岭土发生烧结导致微孔闭塞,孔径分布向中孔和大孔集中,比表面积减小,吸油值较低。因而煅烧高岭土的吸油性能与其比表面积和孔径分布密切相关,孔径分布越集中于微孔,比表面积越大,其吸油值越高。A washed kaolin clay was calcinated in the temperature range from 600 ℃ to 1 000 ℃. The microscopic morphology, the phase, the specific surface area and pore size distribution of the products were characterized by field emission scanning electron microscopy, X-ray diffraction and BET nitrogen adsorption measurement, respectively. The relationship between oil absorption and specific surface area was analyzed. The results show that the oil adsorption of calcinated kaolin clay with the smallest average pore size at 750 ℃ is the greatest （i.e., 80.272 g/100 g）. The oil adsorption of calcinated kaolin clay became greater due to the larger specific surface area and the presence of the more concentrated micropore and mesopore in the pore distribution at the calcining temperature of 〈 800 ℃. The microporous occlusion of the kaolin clay occurred when calcinated at 800 ℃, causing the more concentrated mesopore and macropore in the pore distribution. As a result, the oil absorption reduced. The oil absorption of the calcinated kaolin clay was closely related to the specific surface area and the more concentrated micropore in the pore distribution.

关 键 词：比表面积 吸油值 煅烧高岭土 水洗高岭土 孔径分布 

分 类 号：TD985[矿业工程—选矿] TB321[一般工业技术—材料科学与工程]