LENG Hao，WANG Zhe，CHENG Huan，LING Longyuan，CHEN Haiyan

(School of Environment and Resource，Southwest University of Science and Technology，Mianyang 621010，China)

Abstract:Three kinds of ultrafine kaolin samples were prepared by adjusting the process parameters of the steam jet mill.The particle size,morphology and mineral analysis were carried out on them.The ultrafine kaolin samples were added into agar aerogel as flame retardant,and the flame retardant properties of agar-kaolin composite aerogel were tested.The results show that the median diameters of the prepared ultrafine kaolin samples are 3.717，3.034,1.929 μm when the speed of the steam jet mill classifier is 700,1 400,3 500 r/min respectively,under the premise that the crushing pressure is 0.5 MPa and the steam temperature is 260 ℃.The diameter and thickness of ultrafine kaolinite layered crystals are significantly reduced,the particle size becomes more uniform,and the particle size distribution is more concentrated.The steam jet mill can effectively destroy the bonding bonds of the crystalline layered structure of kaolinite without changing the mineral phases.Compared with kaolin raw material,the ultrafine kaolin is more uniformly dispersed in the aerogel material,and the obtained agar-kaolin composite aerogel insulation material has better flame retardant performance,with its limiting oxygen index increased from 26.3% to 32.2% and vertical combustion UL-94 rating increased from V-1 to V-0 grade.

Keywords:ultrafine kaolin;steam jet mill;aerogel;flame retardancy

中图分类号：TU7                              文献标志码：A

文章编号：1008-5548(2022)04-0062-08

DOI:10.13732/j.issn.1008-5548.2022.04.007

收稿日期： 2022-01-09， 修回日期：2022-04-28，在线出版时间：2022-06-20 13:53。

基金项目：四川省科技厅重点研发项目，编号：2020YFG0186。

第一作者简介：冷豪(1995—)，男，硕士研究生，研究方向为阻燃材料研究。E-mail：419705870@qq.com。

通信作者简介：林龙沅(1981—)，男，教授，博士，硕士生导师，研究方向为超音速气流粉碎机理及技术、通风除尘净化(职业卫生安全方向)。E-mail：LLy7572@126.com。