In this paper, mullite spinning sol was prepared by sol-gel technology with aluminum hydroxide as aluminum source and silica sol as silicon source. The viscosity and rheological properties of the spinning sol were studied by using steady-state and dynamic test modes. Continuous mullite gel fibers were prepared by dry spinning, and the spinnability of the sol was evaluated. The results show that the temperature has little effect on the non-Newtonian index and structural viscosity index of the sol, which will be beneficial to the adjustment of the spinning process. High solid content is conducive to the spinning of mullite gel fibers. The gel fibers prepared with high solid content sol are finer and have better spinning stability.

the changes in viscosity or rheological properties during the static process of mullite sol have a significant impact on its spinnability. Herein, mullite spinning sols were prepared by vacuum concentration using aluminum chloride and acidic silica sol, and polyvinyl alcohol as the spinning aid. The influence of storage temperature and time on the stability of sol were studied. And focused on the influence of temperature changes and time on the rheological properties of mullite sols, such as non Newtonian index, structural viscosity index, and viscous flow activation energy. The stretchable fiber length of the sol is used as an evaluation of its spinnability. The results showed that low temperature is beneficial for the preservation of the internal structure of the sol and for maintaining its spinnability for a long time. High temperatures can accelerate the aggregation of rubber particles to form large particles, and lose spinnability in a short time. Furthermore, the sol stored at low temperature for 14 days can continuously draw the gel fiber over 100 m, and mullite ceramic fibers with good morphology, small grains and uniform diameter distribution were obtained after calcination at 1200 ℃.