characterization of clay waste from industrial sand mining as raw material for the ceramic industry

Abstract

The reuse of clayey waste from sand mining of the Piramboia Formation represents an option for reducing the environmental impact generated by the disposal of such waste in decantation tanks. To test this hypothesis, these wastes were utilized in the production of ceramic materials, mainly bricks. To this purpose, samples collected in the thickeners and decantation tanks were subjected to mineralogical, chemical and ceramic studies. The samples studied from the thickeners presented homogeneous characteristics, high plasticity and kaolinite as the dominant clay mineral. The samples from the decantation tanks were more heterogeneous, and exhibited low plasticity and higher amounts of silicon dioxide. The clays collected in the thickeners proved to be more appropriate for the production of bricks because of their homogeneous characteristics, which facilitate extrusion and reduce dimensional defects of the pieces, thereby providing a qualified final product.