Desenvolvimento de membranas cerâmicas tubulares com resíduo de caulim.

Abstract

The industry of kaolin improvement produces a residue in a great amount that can cause serious damage to the environment. It is needed to find solutions from industry and scientific community to recycle this residue as an alternative material to produce new goods. The use of inorganic membrane separation process is a new technology in the improvement of several industrial processes. The number of porous ceramic membrane application is great and properly established. The search for low cost materials or residues to produce porous ceramic membrane is important to facilitate this requires. So, the aim of this work is to develop tubular porous ceramic membranes, using kaolin residue and raw materials, such as, bentonite and talc, and prepared by extrusion process. It was used four sintering temperatures (850°C, 900°C, 950°C and 1000°C) to study the influence of these temperatures in the membrane characteristics. It was done chemical analysis of the ceramic mass before firing, by X-ray fluorescence, identifying high content of Si02 , A l 203 and MgO. The X-ray diffraction, for the ceramic mass before firing indentified mica, talc, kaolinite and quartz, e for the ceramic mass after firing, at 950° and 1000°C, identified quartz, kaolinite and also cordierite. In relation to morphological characterization, it was used SEM that show the presence of pores and no defects on the membrane surface and mercury porosimetry shows pores with average size of 0,159, 0.162, 0.175 and 0.220 um, that is appropriated to microfiltration, and porosity of 43.4, 44.3, 42.2 and 41.2%, for sintering temperature of 850, 900, 950 and 1000°C, respectively. The permeate water flow were 53.87 l/h.m2, 65.85 l/h.m2, 66.20 l/h.m2 and 72.75 l/h.m2 for membranes sintering at 850°C, 900°C, 950°C and 1000°C, respectively. From the separation test with water from artesian well it was observed that the membrane sintering at 950°C gives the best permeate flow of 50.55 l/h.m2 and better performance of 97.60 of reduction in turbidity.