Preparation of SiC Porous Ceramic for Application in Filter Plate Supports

Abstract

In order to improve the efficiency of solid-liquid separation, dewatering and filtration, as well as to reduce the loss of concentrate and production costs, silicon carbide porous ceramic filter plate with high porosity and high bending strength was prepared by using the particles close packing method adding proper amount of adhesives and sintering additives at 1450 oC. The porosity of the fired samples was evaluated by Archimedes law. The morphology and properties of the samples were characterized. Effects of SiC grains gradation, pore formers content, molding pressure and soaking time on the bending strength and porosity of ceramic filter plate was studied. SiC porous ceramic composition was prepared by mixing 90wt% and 10wt% SiC powders with D50 of 200.7 μm and 312.6 μm, respectively, 4% walnut powder as pore former and 5% Kaolin clay as binder. The sample was pressured at 8 MPa and fired at 1450 oC for 30 min, and endowed with 6-8 μm of the average pore diameter, 41% of the porosity and 11 MPa of the bending strength, respectively, which is especially not easy to plug hole. The obtained results can be applied in ceramic filter core parts for heavy metal concentration.