A method for preparing a ceramic fiber filter tube with high air permeability, including: using mullite short fibers as aggregates, adding glass fibers and silica sol as sintering aids, obtaining a ceramic fiber filter tube green body by using a filterer-pressing forming process, and obtaining the ceramic fiber filter tube with high air permeability by freeze-drying and heat treatment in turn. The combination of two sintering aids with different properties can effectively improve the performance of ceramic fiber filter tube prepared by a wet forming technology. At the same time, the freeze-drying treatment can block the migration path of nanoparticles in the silica sol to the surface of the ceramic fiber filter tube due to the capillary force, so that the properties of the prepared ceramic fiber filter tube are more uniform, providing a reference for the preparation of a ceramic fiber membrane with high flux.

The present disclosure relates to the field of ceramic filtration membranes and methods for their preparation and use. In particular, the present disclosure relates to ceramic membranes prepared from SiC precursors comprising a mixture of two SiC powders each one with -SiC crystalline phase and another with -SiC crystalline phase and different particle sizes, respectively.

The present invention relates to a method for one-step regulation of a pore structure and surface properties of a silicon carbide (SiC) membrane. The method comprises: first, fully mixing SiC powder with a sintering aid, and then synergistically regulating a pore structure and surface wetting properties of a SiC membrane by controlling a molding pressure and a sintering condition. The amount of SiO.sub.2 generated by oxidation of SiC is controlled, and in situ reaction of SiO.sub.2 and the sintering aid is prompted to generate a neck connection, such that a sintering temperature of the SiC membrane can be reduced, and the strength and corrosion resistance properties of the SiC membrane can also be improved. The degree of sintering of the SiC membrane is effectively controlled by means of the regulation of the molding pressure and the sintering temperature. It is a simple method for one-step regulation of a pore structure and surface properties of a SiC membrane. The SiC membrane prepared has porosity adjustable in a range of 13% to 48% and a pore size adjustable in a range of 0.17 m to 1 m; and the SiC membrane has an initial dynamic water contact angle in a range of 12.01 to 66.8 and an underwater oil contact angle adjustable in a range of 120.3 to 155.1. The SiC membrane prepared has high bending strength and pure water permeation properties and show a broad application prospect in the field of oil-water separation and emulsion preparation.

A method for preparing a ceramic fiber filter tube with high air permeability, including: using mullite short fibers as aggregates, adding glass fibers and silica sol as sintering aids, obtaining a ceramic fiber filter tube green body by using a filterer-pressing forming process, and obtaining the ceramic fiber filter tube with high air permeability by freeze-drying and heat treatment in turn. The combination of two sintering aids with different properties can effectively improve the performance of ceramic fiber filter tube prepared by a wet forming technology. At the same time, the freeze-drying treatment can block the migration path of nanoparticles in the silica sol to the surface of the ceramic fiber filter tube due to the capillary force, so that the properties of the prepared ceramic fiber filter tube are more uniform, providing a reference for the preparation of a ceramic fiber membrane with high flux.

Described are porous, sintered metal bodies that include multiple layers made from different metal particles and that may be useful as porous filter membranes, as well as methods of making and using the porous, sintered metal bodies.

A filter for the filtration of a fluid, such as a liquid, includes or is constituted by a support element made from a porous ceramic material, at least a portion of the surface of the support element being covered with a porous membrane separating layer, the membrane separating layer being constituted essentially of silicon carbide (SiC), its porosity being between 10% and 70% by volume, the median diameter of its pores being between 50 nanometers and 500 nanometers, its mean thickness being between 1 micrometer and 30 micrometers, and its tortuosity being less than 1.7.