Análise mineralógica e aplicações tecnológicas do resíduo da extração de esmeraldas dos Garimpos de Carnaíba e Socotó/BA em composição de massas cerâmicas

Mineralogical analysis and technological applications of the residue from extraction of emeralds from the Carnaíba and Socotó/BA mines in ceramic mass composition

Abstract

Emerald mining in the Carnaíba and Campo Formoso Mountains, in Bahia, generates significant environmental waste. This study aimed to characterize the waste from the Carnaíba (Pindobaçu-BA) and Socotó (Campo Formoso-BA) mining sites and to develop clay-based composites for the production of ceramic materials in civil construction. Formulations were prepared with varying concentrations of clay and mineral residues (10, 20, 30, 40, and 50 %) and were subjected to chemical and mineralogical analyses using X-ray fluorescence and diffraction. The samples were sintered at different temperatures (850, 900, 950, 1000, 1100, and 1200 ºC) and underwent technological tests (water absorption, apparent porosity, linear shrinkage, loss on ignition, apparent density, and flexural strength). The results revealed favorable characteristics for the ceramic industry, with the predominant presence of SiO₂ and Al₂O₃ affecting plasticity, and fluxing elements influencing thermal properties. The mineralogical diversity, including mullite, metakaolinite, indialite and quartz, contributed to the composites' strength and stability. The C20 (20 % Carnaíba residue) and S10 (10 % Socotó residue) formulations showed the best results, standing out for their technical feasibility and sustainability in ceramic production.