Formulação e caracterização de um compósito cerâmico fabricado a partir do rejeito do granito Asa Branca com adição dos produtos da combustão do carvão mineral e cal

Abstract

The vast majority of industrial processes are prone to produce residues, particularly in the fields of ornamental stones processing and coal combustion thermoeletrics. Most of these residues constitute environmental hazards. Therefore, their disposal must follow strict rules and legislations which can increase costs. In the present work, the feasibility of producing ceramic parts with such residues was investigated. Granite powder and coal combustion products were mixed with lime in different proportions. Small disks were produced by uniaxial compression, containing a mixture of 55% weight of Asa Branca granite powder and two different proportions of coal ash and lime (35 10 and 25 20, respectively). Samples were sintered on air in a muffle furnace at different temperatures (1050 °C, 1100 °C, 1150 °C, 1175 °C, 1185 °C and 1200 °C), in order to determine the optimum sintering temperature for each batch. Upon sintering, they were visually inspected and then characterized by X ray diffraction, measurements of sintering shrinkage and axial compression tests. Results obtained showed the feasibility of using such residues as raw materials for the formulation of a composite ceramic material which can find application in civil construction, depending on the proportion of the components in the mixture. Further work is needed in order to optimize processing and properties.