The statistical analysis and technological response of the proposed
mixture suggest that sludge can be used as a substitute for
clay in the formulation of clay masses. According to the conditions
used in this study, none of the mixtures can be used for production
of massive or hollow bricks. However, in compliance with reference
values for massive and hollow bricks regarding ignition loss,
shrinkage upon drying, and bending rupture tension, and the formation
of albite, gehlenite, and anorthite phases (which confer
higher mechanical resistance to structural ceramic materials) the
mixtures B, C, D, and F at 850 and 950 C, should be tested in the
ceramic industry on a pilot scale in order to evaluate their suitability
for the production of interior coatings or acoustic bricks.