Characterization of mineral wools obtained from ornamental rock wastes

Abstract

The study aimed to characterize the mineral wools obtained from wastes of the cutting step of marble and granite, in order to evaluate the possibility of their use on an industrial scale. Mixtures of marble and/or granite wastes were prepared in order to reach the chemical composition of rock and glass wools. The batches were melted in an electric arc furnace in laboratory scale at 1450°C and casted with water, in order to obtain a higher cooling rate. Characterization work was performed in batches that formed vitreous material, and with superior incorporation of the residues: 11.7% and 14.6% of marble waste with glass wool and rock wool, respectively; 78.3% and 91.6% of an association of marble and granite wastes with glass wool and rock wool, respectively. Computational thermodynamics was used in order to obtain the main phases at 800°C and determine the liquid and solid content at 1400, 1450 and 1500°C. In addition, the materials obtained were characterized via chemical analysis using X-ray fluorescence, DTA, X-ray diffraction and SEM. The results indicate that the marble and granite waste are composed mainly of CaO (34.7 wt.%) and SiO 2 (66.3 wt.%), respectively. An amorphous crystalline structure was obtained in all tests, indicating that this material can be used as an insulation material. The crystallization temperatures were determined around 800°C.

Mullite-Based Ceramics from Mining Waste: A Review

“…The ornamental industry uses a wide variety of rocks, such as agate, gneiss, granite, granodiorite, marble, quartzite, rhyolite or varvite, which are sawed into the desired forms and dimensions. Alves et al [141] estimated that near 50% of the ornamental rock extracted corresponds to wastes originated during block sawing. As a result, huge amounts of residues are generated worldwide and damped near the natural stone sawmills without any potential application, which causes environmental implications.…”