The ornamental rock industries generate huge amounts of solid wastes (fine powders). These wastes as disposed in the environment generate negative environmental impacts. In this work a study was done on the influence of an ornamental rock waste in the technological properties and microstructure of vitrified floor tile. A series of ceramic pastes were prepared with additions of up to 30 wt% of waste. Ceramic pieces were prepared by uniaxial pressing and sintered between 1190 and 1250 ºC using a fast-firing cycle. The following technological properties were determined: linear shrinkage, water absorption, apparent density, and flexural strength. The microstructure and phase analysis evolution were accompanied by scanning electron microscopy and X-ray diffraction. The experimental results showed that the addition of up 30 wt% of WTS caused significant variations in the technological properties of the ceramic paste used as reference. The microstructure of the floor tile pieces also was influenced by the ornamental rock waste added. The results also showed that the replacement of sodic feldspar by ornamental rock waste tends to improve the quality of the vitrified floor tiles.
waste; ornamental rock; floor tile; microstructure; properties
