Análise de Dados Cinéticos para a Síntese de Carbeto de Tungstênio por Reação Gás-Sólido

Abstract

Tungsten carbide is an inorganic chemical compound containing equal parts of a ceramic material (carbon) and a metallic material (tungsten), of high density, designed for application in aggressive environments in which the surface of the parts are subjected to wear due to abrasion and severe erosion. The synthesis of refractory carbides by gas-solid reaction is industrially interesting since these materials can be used in the manufacture of many electrical and electronic devices, such as, for example, exhaust fan blades, cold forming tools; mechanical seal seats; mining slurry pumps; double pendulum valve, etc.). In this work, a kinetic study of the synthesis of tungsten carbide (WC) is carried out using chromatographic data through the gas-solid reaction. The methodology used consisted of the acquisition of bibliographic data referring to the reactions of tungsten carbide synthesis followed by the development of the kinetic study for the reactions. First and second order models were used. It was possible to estimate the first and second order kinetic constants for the following values: k (rate constant) = 0.00181/min, R² = 0.9646 for synthesis reactions at T = 850°C, Q (flow rate) = 17 L/h with 2 hours of isotherm using the first order model and k = 0.00181/min with R² = 0.9663 for the second order model. The first-order model (mean R² = 0.937) seems to explain the reaction phenomenon with greater quality than the second-order model, obtaining higher linear correlation coefficients (mean R² = 0.8118).