Print version ISSN 0366-6913
On-line version ISSN 1678-4553
ALBUQUERQUE, F. R. et al. Processing of reticulated ceramics using natural raw material. Cerâmica [online]. 2006, vol.52, n.322, pp.185-192. ISSN 0366-6913. http://dx.doi.org/10.1590/S0366-69132006000200011.
Porous reticulated ceramics were obtained using a natural raw material (AF) usually employed in the production of tiles and bricks, with kaolinite (AC) addition. The AF raw material is constituted of quartz and feldspar. Ceramic pieces were processed using the polymeric sponge impregnation. Viscosities of the slurries with 70% of solids (wt./wt.) were optimized using sodium polyacrilate (PAA-Na) as deffloculant. Suspensions without AC addition presented a viscosity of 600 mPa.s, decreasing to 300 mPa.s after addition of 20% (wt./wt.) AC. The optimized amount of PAA-Na was 2.0% (wt./wt.). Tixotropy and pseudoplasty of the slurries made the impregnation process easier. Polymeric sponges of 5, 10 and 40 pores/cm were used. Ceramic pieces were sintered at 1100 and 1200 ºC. X-ray diffractograms indicated the quartz dissolution at 1200 ºC, leading to a material composed of mullite and vitreous phase. Reticulated ceramics with a porosity of 10 pores/cm presented a rigid structure with mechanical strength higher than 1.70 MPa, with darcian permeability constant of about 3.58 x 10-9 (±10.0 %) m2.
Keywords : traditional ceramics; shaping; suspensions; clays; functional applications.