Obtenção de uma vitrocerâmica a partir de resíduos da perfuração de poços de petróleo e do beneficiamento do caulim

Abstract

The production of wastes in many industries has been a major concern for years. Recently, with the increase of environmental awareness, many guidelines have been developed around the countries to protect the world and society. The first tier on a hierarchy of waste management is minimizing its production, followed by reuse or recycle. In the oil industry, drilling activities generates a considerable amount of wastes. The mining industry also produces a large amount of wastes considering the whole production line: from the extraction to final product the loss of raw material is about 70%. Several authors have studied new products development incorporating these wastes, especially ceramic materials due to the heterogeneity of their composition. Therefore, this study aims to develop a glass ceramic from drill cuttings of oil wells from Potiguar basin and tailings from kaolin processing in the city of Equador/RN. As an innovative proposal, the residue samples were collected and their samples characterized to obtain the best formulation based on a composition SiO2- Al2O3-CaONa2O-K2O-MgO. The mixture of 10g of drill cuttings, 5g of kaolin waste and 2.5g of Na2O was melted at 1500 °C for 1h, generating a precursor glass then characterized by X-ray fluorescence (XRF), thermogravimetry and thermal expansion analysis to support the production of the glass ceramic. It was also made an X-ray diffraction (XRD) following the temperature increasing gradually to study the densification and crystallization of the material. As a subsequent step the glass powder was compacted (forming a pellet) and also deposited on a metal to test the interaction between its coefficients of thermal expansion and to check the viability of using the glass ceramic formed in solid oxide fuel cells (SOFC’s). Both samples were sintered at 850 °C for 30 minutes. Although the proposed application was not feasible due to the divergence between the metal and glass coefficients of thermal expansion (CTE), the glass ceramic structure, analyzed by scanning electron microscopy (SEM) and dispersive energy spectroscopy (DES), proved the formation of a semi crystalline structure with amorphous phase.