The process of adding a sintering aid involves incorporating a pore former into the ceramic mixture, which occupies a certain space within the green body. After sintering, the pore former is removed, leaving behind air pockets to produce porous ceramics. The process for producing porous ceramics with a pore former is similar to the standard ceramic process. Pore formers are categorized into inorganic and organic types, with inorganic pore formers including salts like ammonium carbonate, ammonium bicarbonate, and ammonium chloride, which are decomposable at high temperatures, as well as coal powder and carbon powder.

Organic pore-forming agents primarily consist of natural fibers, high molecular polymer, and organic acids. The shape and size of the pore-forming agent particles determine the shape and size of the pores in the porous ceramic material. The forming methods for porous ceramic materials are similar to those for conventional ceramics, mainly including molding, extrusion, isostatic pressing, weaving, injection, and slurry casting.