Fabrication and characterization of mullite fiber-based porous ceramics with mixed fiber lengths for high-temperature gas filtration

The emissions and particulate pollutants (PM) from industrialization and other human activities have become a significant threat to human health. Researchers have experimented with various fiber-bonded filters, but there are still relatively few products with good high-temperature resistance. In this paper, a fiber-bonded porous ceramic with high porosity was prepared by vacuum filtration combined with freeze-drying using two homemade mullite fibers with different length-to-diameter ratios as raw materials and mullite sol as binder. When the content of fine fibers is 40 %, the product has a better overall performance, its density is 0.63g/cm 3 , porosity is 74 %, strength is 0.77 MPa, thermal conductivity is 0.153 W m −1  K −1 . When the airflow rate of 2 L/min, the pressure drop is 80 Pa, the filtration efficiency of about 99 %, the QF is 0.08 pa −1 , The mullite fiber-bonded porous ceramics prepared through a simple process exhibit excellent filtration performance, offering a wide range of potential applications.