Influência da presença de óxidos no aquecimento micro-ondas de arenitos

Abstract

In the drilling of wells containing oil, drills are used that, when penetrating the rocky matrix, generate fragments, known as gravel. The gravel is transported to the surface by the drilling fluid, which has low biodegradability, making it necessary to separate it so that the gravel can be disposed of in an environmentally friendly manner. Microwave drying is being used to decontaminate these cuttings, as it has a high removal efficiency compared to conventional equipment. Microwave heating is strongly influenced by the chemical composition of the rock matrix. Therefore, in this work, the influence of the presence of iron, aluminum, manganese and calcium, which are oxides commonly present in contaminated gravel on the microwave heating of a sandstone was verified, in order to spread the practicality and efficiency of this decontamination technique. The tests were carried out in an adapted bench microwave, in order to verify how the variations in composition affect the temperature kinetics and heating rate. Based on the results obtained, it was possible to identify that iron oxide has greater sensitivity to microwaves compared to aluminum oxide, due to the fact of the electromagnetic properties present in iron, resulting in a higher heating rate. Manganese oxide was the one with the highest heating rate, however, an abnormality in the heating of the sample was observed after a certain time of exposure to microwaves. For not absorbing properly the microwave, calcium oxide showed the lowest rate of heating compared to the others. By the results obtained, it was also possible to develop a correlation to predict how each type of oxide studied behaves when subjected to microwave heating.