The use of computer simulation to predict the behavior of devices and materials allows for the acceleration of system operation and reduces costs, as it eliminates the need to build prototypes for testing. This work proposes the construction of 3 models with different complexities to simulate the electrical behavior of a solid electrolyte fuel cell. Experimental data were compared with simulation data. The experimental data were obtained from the production of a solid YSZ by tape casting, sintered at 1550 °C. The material was characterized using impedance spectroscopy in atmospheric air. From the experimental data, a computer simulation was conducted by using commercial code (COMSOL Multiphysics v.5.4). The construction of the model was developed to 1D, 2D axisymmetric and 3D dimensions to simulate an electrolyte to use in cylindrical planar SOFC. Nyquist Impedance graphics were plotted for the three geometries in comparison with the experimental value. No variation was observed between the curves obtained by the different geometries for the same interface. In other words, the interface complexity did not interfere in the result obtained for the same experimental data. We concluded that the 1D model is ideal to predict the influence of operational parameters because it is simpler and saves analysis time, maintaining the reliability and accuracy of the results.

RESUMO Porcelanas são cerâmicas multifásicas produzidas a partir de matérias-primas naturais e utilizadas na fabricação de uma grande variedade de produtos. Este trabalho teve como objetivo verificar a viabilidade da substituição total e parcial do feldspato presente na formulação de porcelanas, por resíduo de rochas ornamentais oriundo do processo de polimento de uma empresa de médio porte. As matérias-primas selecionadas foram cominuídas em moinho de bolas a úmido e posteriormente peneiradas em malha 80 mesh. Foram realizadas análises de fluorescência de raios X, difração de raios X, microscopia eletrônica de varredura e também distribuição de tamanho de partículas. Para avaliar os efeitos desta substituição foram formuladas quatro composições variando a quantidade de resíduo em substituição ao feldspato, nestas amostras foram feitas análises de distribuição de tamanho de partículas, posteriormente os corpos de prova foram prensados e sinterizados em temperaturas que variaram de 1100 a 1250°C em forno elétrico resistivo com patamar de 2 horas. A caracterização das porcelanas foi feita por medidas de porosidade aparente, absorção de água e densidade aparente pelo método de Arquimedes, também foram realizadas medidas de resistência mecânica feita por flexão em três pontos, difração de raios X para a análise das fases formadas e microscopia eletrônica de varredura para a análise microestrutural. Os resultados mostraram que é viável a substituição do feldspato por resíduo de polimento de rochas ornamentais, uma vez que as propriedades físicas das porcelanas como absorção de água e resistência mecânica são pouco alteradas. Além disso, a adição de resíduo diminui as temperaturas necessárias para sinterização, sendo no entanto, necessário, ter maior controle dessa temperatura no processo produtivo, devido ao menor intervalo de queima.

ABSTRACT Porcelains are multiphase ceramics produced from natural raw materials and used in manufacturing a wide variety of products. This study aimed to verify the feasibility of the total and partial replacement of feldspar present in the formulation of porcelain by ornamental stones residue coming from the polishing process of a medium-sized company. The materials selected were comminuted in the wet ball mill and subsequently sieved through 80 mesh Fluorescence X-ray analysis, scanning electron microscopy and also particle size distribution were made. They were formulated four compositions by varying the amount of residue replacing feldspar. In these samples the particle size distribution analyzes were performed and subsequently the samples were pressed and sintered at temperatures ranging from 1100 to 1250°C in resistive electric oven for 2 hours. The porcelains characterizations were made by apparent porosity, water absorption and apparent density by the Archimedes method; mechanical resistance measurements were also performed made by bending at three points; X-ray diffraction for the analysis of the phases, and scanning electron microscopy for microstructural analysis. The results showed that it is feasible to replace the feldspar for ornamental rocks polishing residue, since the physical properties of the porcelain as water absorption and mechanical strength and are slightly changed. Furthermore, the addition of residue reduces the sintering temperature, however, it is necessary to have greater control of this temperature in the production process due to the lower firing range.