Produção de carbeto de molibdênio a partir de mineral encontrado no interior do Rio Grande do Norte

Abstract

This work proposed a new alternative route of synthesis of nanostructured molybdenum carbide from the base mineral extracted from the city Carnaúba dos Dantas - RN, through gas - solid reactions at low temperature, as well as provided a integrated theoretical view of the morphologic formatation of the synthetized materials. Initially, this starting ore were into a grinding process, followed by milling and sieving, and its characterization performed through X-ray fluorescence (XRF) and X-ray diffraction (XRD), to analyze if its characteristics are satisfactory for the synthesis. In the sequence, the ore treatment was carried out through leaching and hydrothermal treatments. Therefore, it was done synthesis of the precursor, a more reactive reagent, used in the synthesis of the carbide by the gas-solid reaction. The precursor was characterized by granulometric analysis (AG), X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric, thermodifferential and calorimetric (TG/DSC) analysis, infrared (IR) spectroscopy, electron microscopy (SEM) and dispersive energy spectroscopy (EDS). The synthesis reaction occured between the precursor and a gas mixture of H2 / CH4, where hydrogen is the reducing gas and methane is the carbon source. The synthesized nanostructured molybdenum carbide was characterized by X-ray fluorescence (XRF), Xray diffraction (XRD) with refinement by Rietveld method, specific surface area analysis (BET), scanning electron microscopy (SEM) and spectroscopy of dispersive energy (EDS).