Recycling of barite ore tailings into porcelain: microstructure and dielectric properties

Abstract

Purpose. To study the dielectric properties of porcelain obtained from a mixture of sand, kaolin, and feldspar. The latter has been partially substituted with solid barite wastes (SBWs). Methodology. The study involves preparation of porcelain using conventional solid-state reaction methods, employing two firing temperatures (1200 and 1300 °C) and a soaking time of 3 hours. SBWs are progressively added to the mixtures at levels of 0, 10, 20 and 30 wt%, replacing feldspar content. Structural and dielectric characterizations are conducted to examine the influence of SBWs substitution on macroscopic dielectric properties. Microstructural observations reveal various crystalline phases and micropores, contributing to property effects. Following sintering at 1200 °C, primary mineralogical phases include mullite, anorthite, and quartz. At 1300 °C, the celsian phase emerges alongside anorthite and quartz phases. The technological attributes of the produced porcelain samples, encompassing dilatometric properties, apparent density, and porosity, are determined. Findings. Dielectric characterization, conducted within the frequency range of 102–105 Hz, demonstrates that the relative constant permittivity values rise from 4.3 to 7.4 for samples sintered at 1200 °C and from 5.1 to 9.9 for those fired at 1300 °C, specifically for samples containing 10 wt% SBWs. Additionally, the dielectric loss tangent decreases with increasing sintering temperature. The macroscopic permittivity of porcelains can be accurately calculated using a mixing rule, which aligns well with experimental results. Originality. The original contribution lies in the use of 10 wt% Solid Barite Wastes (SBWs) from the Boucaid mine in order to effectively create environmentally friendly porcelain insulators. The study showcases the potential of SBWs as a partial substitute, thus promoting sustainability in porcelain insulator production. Practical value. The results of this study hold practical significance for the ceramics and insulator manufacturing industries by providing insights into enhancing the dielectric properties of porcelain through the incorporation of SBWs. This approach contributes to the production of environmentally friendly insulators.