A METHOD OF PRODUCING A CERAMIC FILTER MEMBRANE, A METHOD OF IMPROVING A CERAMIC FILTER MEMBRANE AND THE CERAMIC FILTER MEMBRANE OBTAINED BY THE METHOD

A method of producing a ceramic filter membrane comprising i. providing a porous substrate; ii. providing a membrane forming dispersion comprising a first fraction of ceramic particles having a larger medium grain size (D-50) and a second fraction of ceramic particles having a smaller medium grain size(D-50) than the first fraction of the membrane forming dispersion; iii. applying a layer of the membrane forming dispersion onto a surface of the porous substrate, drying and sintering the ceramic particles to form a coherent membrane layer on the porous substrate, the membrane layer has a membrane layer surface facing away from the porous substrate; iv. providing a surface treatment fluid dispersion comprising a first fraction of ceramic particles having a medium grain size (D-50) which is in the interval from about -10 % to about + 10 % relative to the larger medium grain size of the membrane forming dispersion and a second fraction of ceramic particles having a smaller medium grain size (D-50) than the first fraction of the surface treatment fluid dispersion; v. surface treating the membrane layer by passing the surface treatment fluid dispersion in a main flow direction substantially along the membrane layer surface in a turbulent flow while simultaneously providing a pressure difference over the membrane layer to cause that a part of the surface treatment fluid dispersion is passing into the membrane layer and vi. drying and sintering the surface treated membrane to obtain the ceramic filter membrane.