  Ceramic based materials covered with a mixture of mullite and zircon on the
top, strengthened by the addition of zinc and magnesium compounds at different
rates (37 % and 50 %) and made by a co-precipitation method are studied. The
thermally treated and shaped materials prepared in the shape of cylindrical
samples were modified to obtain different porosities. The addition of zinc to
the ceramic based material leads to a significant increase and control of the
density of porosity compared to the addition of magnesium. The porosity of all
the materials was characterized. The permeability characteristics and the
ability for all the pellets to absorb water until the saturation were also
studied as a function of the porosity.
