超声波辅助插层-剥离法制备煤系高岭土微粉的研究

我国煤系高岭土储量丰富,为满足造纸、纺织等行业个性化的需求,通常要对其进行深加工。以山西朔州煤系高岭土为原料,分别在恒温磁力搅拌和超声波作用下探究了煤系高岭土/二甲基亚砜(DMSO)插层复合物制备的最佳条件,在插层复合物的基础上对煤系高岭土进行超声辅助剥离,制备得到高岭土微粉,并利用XRD、SEM、BET、TG-DSC等方法分析表征样品。正交实验结果表明在磁力搅拌条件下DMSO用量、插层时间以及插层温度均对插层率具有一定的影响,引入超声波有利于高岭土插层率的提升。插层复合物经超声辅助剥离后晶粒厚度明显减小,高岭土片层状结构大体上呈现碎片化,仅保留少部分大的片状结构,其边缘碎化,整体上也出现碎裂的趋势。剥离样品的比表面积和孔径均大幅度增加,为硬质高岭土的剥离和超微细粉体的制备提供了新的思路。

Research on Coal-Series Kaolin Micropowder Prepared by Ultrasonic Assisted Intercalation-Exfoliation Method

Chinese coal-series kaolin is rich in reserves. To meet the needs of industries such as papermaking and textiles, it usually needs to be further processed. The optimum conditions for the preparation of coal-series kaolin/DMSO intercalated composites were explored using Shanxi Shuozhou coal-series kaolin as raw materials under constant temperature magnetic stirring and ultrasonic waves. Ultrasonic assisted stripping of coal-series kaolins was carried out on the basis of intercalated composites to prepare kaolin fine powder and XRD, SEM, BET, TG-DSC and other methods were used to analyze and characterize the sample. Orthogonal experimental results show that the amount of DMSO, intercalation time and intercalation temperature all have certain effects on the intercalation rate under magnetic stirring conditions. The ultrasonic wave is beneficial to the process of intercalation of kaolin. The thickness of the grains of the intercalation composites after ultrasonic assisted exfoliation are significantly reduced. The lamellar structure and edges of few kaolinite with large lamellar structure are both fragmented, and the the tendency of cracking is obvious. The specific surface area and pore size of exfoliated sample has been increased twice, providing new ideas for the exfoliation of hard kaolin and the preparation of ultrafine powder.