Fabrication of ceramic membranes from nano–rosette structure high alumina roller kiln waste powder for desalination application

Abstract

In the manufacture of some ceramic products, in particular wall and floor tiles, roller kilns are used for firing. In this work, the kiln rollers grind waste is recycled and used as raw material in the production of ceramic membranes for use in water filtration. The powder waste was analyzed by XRF for chemical composition, XRD for mineralogical composition, DTA and TGA for thermal behavior, TEM, particle size distribution, and powder density. It was determined that the particles are nano–sized and have rosette–like segregations structure.Ceramic membranes were prepared by in disc form using an organic binder (PVA) with concentrations ranging from 2% to 8% by weight. They were subsequently pressed at 25 MPa, dried and fired at firing temperatures ranging from 1100° to 1300°C for 1, 2, and 3 h soaking time. The following properties were then investigated; Apparent and closed porosity, bulk density, water absorption and desalination performance. It was found that the best properties were obtained on firing the prepared ceramic membranes at 1250 °C, where salt separation percentage reached 99% with a flux of 244.5 L m−2 h−1 using a solution of salt concentration 5000 ppm.