Clay-bricks from recycled rock tailings

The aim of this work is to optimize the industrial applications of granite and kaolinite rock tailings in ceramics industry. Three rock tailings are selected to be characterized and equally mixed for testing. The samples are characterized using XRD, XRF, polarizing light microscope, cathodoluminescence, X-ray micro-computed tomography (3d-µCT) and SEM microscopy attached with EDAX. The rock tailings mixed batch is non-bloatable and is located in the mullite field on the FeOFe2O3-Al2O3-SiO2 phase diagram. In addition to primary mullite, type II secondary mullite of aspect ratio (3-10:1) is characteristic within aluminosilicate glassy matrix. The 3d-µCT shows pores of lower surface area at 1200 °C due mainly to the existence of isolated rounded closed pores. The physical characteristics of the fired batch, at 1200 °C show that it can be used in the manufacture of building clay-bricks.