Aproveitamento de resíduo do quartzito para a produção de silício de grau metalúrgico

Abstract

The exploitation of quartzite in Ceará, despite its economic significance, generates substantial environmental impacts due to the improper disposal of silica-rich waste, with only 15% of the extracted raw material being utilized. In this context, this study evaluated the feasibility of reusing these residues for the production of Metallurgical-Grade Silicon (SiGM), a key raw material for high-tech industries. To achieve this, samples collected from mining fronts and waste piles were subjected to beneficiation and thermal purification processes, followed by chemical and mineralogical analyses using X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), and Rietveld refinement. The results revealed a predominance of quartz, along with impurities such as iron, aluminum, and calcium. Thermal treatments in a muffle furnace increased silica purity; however, the levels achieved remained below the 99.9% threshold required for SiGM classification, indicating the need for additional purification steps, either through more advanced chemical or thermal processes. The findings of this study highlight the potential for reutilizing quartzite mining residues, proposing a sustainable alternative that not only mitigates the environmental impact of the sector but also adds economic value to the ornamental stone production chain. Furthermore, the research emphasizes the importance of adopting circular economy practices in mining, fostering a balance between industrial development and environmental responsibility.