A laboratory procedure for the production of a ceramic capillary filter from a high-silica glaze was described and its filtration response was tested in dead-end and periodic vacuum filtration modes with suspensions containing micron and sub-micron clay particles obtained from a ceramic factory wastewater stream. The same glaze raw material ground to two different levels of fineness was used for the production of the porous ceramic substrate and its surface coating. The coating particulate sol was deposited onto the substrate by the filtration technique. The filter substrate and the coating were sintered at relatively lower temperatures (950-980degreesC) than conventional ceramic sintering. The filter indicated a non-clogging behavior in both of the filtration modes, and proved a potential for filtering large volumes of dilute clay slurries by periodic filtration operations. (C) 2002 Elsevier Science Ltd. All rights reserved.