Effect of Porogenic Agent Type and Firing Temperatures on Properties of Low-Cost Microfiltration Membranes from Kaolin
Résumé
The present work is focused on the development and characterization of low-cost flat microfiltration ceramic membranes from West Cameroonian kaolin, cassava starch and bovine bone ash as pore-forming agents, and comparative study of porogens’ influence on membranes properties. These materials were chosen due to their abundance in the country and their beneficial properties. The proportion of porogens varied from 0% (CM0) to 20% and all samples were treated at 1000o-1150oC; membranes without porogenic agent (CM0) gave good results. Linear shrinkage and weight loss values were <7% and <30%, respectively. SEM pictures revealed that inter-granular contacts were formed at 1150oC for all the samples and thus materials densification was more important. Porosity varied between 31% and 52% at 1150oC, and flexural strength increased from 1.07 to 7.79 MPa. Samples containing bovine bone ash contributed to the improvement of membrane microstructure, mechanical and corrosion resistance. Filtration tests through CM04 and CM34 gave turbidity rejection factors of 97.70% and 99.26%, respectively. Decisively, good and low-cost microfiltration ceramic membrane can be developed by using cassava starch and bovine bone ash as porogenic agents.