The use of alunitic kaolin in the production of ceramic membrane support

Although Turkey's kaolin reserves are substantial, much of the reserves are of alunitic type and the largest deposit of this type is located in the Balikesir-Sindirgi Region. Alunitic kaolin cannot be used in ceramic industry owing to its sulphur content. Since alunite is disseminated within kaolin, it is difficult to remove it from kaolin by using mineral processing methods. In this research, alunite existence within the kaolin was used as an advantage in the production of ceramic membrane support since it allows for the occurrence of desirable homogeneous porosity. For this purpose, 3 different alunitic kaolin samples were taken from the Balikesir-Sindirgi Region and were comminuted. The materials obtained were shaped using dry pressing and slip casting methods to obtain ceramic membrane supports. The supports were sintered at 900 degrees C-1300 degrees C for 3 hours. The physical, mechanical and micro-structural properties of the sintered ceramic membrane supports were subsequently determined. The best porosity and strength results were obtained from SB1-1100 and PB1K-1100 coded supports which were made of K1 kaolin (having the highest alunite content).