![]() ![]() The study area belongs to the NW part of the Hellenic mountain chain where, since the Miocene, the crust extended to form a complex pattern of basins. Industry stakeholders would be less susceptible to adapting such alternative raw materials in industrial established processes. However, investigations on the utilization of mining wastes for the production of energy-efficient ceramic materials should be carried out more intensively in the future. Over the last decade, there has been an increasing scientific interest in the use of alternative raw materials in ceramics derived from mining wastes (e.g., iron mining wastes, boron mining wastes, kaolin steriles, granite steriles, coal mining steriles), aiming for the sustainability and symbiosis of industries in conjunction with environmental protection. Previous investigations have demonstrated that there are different mining steriles or other wastes with similar compositions and comparable properties appropriate for new competitive (even improved and energy-efficient) ceramic products, compared to the commercial ones. Globally, there is a wide range of clay-based raw materials used for different ceramic applications, such as mullite-based refractory materials, bricks and tiles, porcelain, stoneware, etc. Ĭlays are the most common raw materials used for ceramic production, especially in the field of traditional ceramics. In this direction, research activities related to the valorization and/or remediation of mining wastes have increased and are focused on the conservation of natural raw materials under the prism of circular economy principles. Therefore, cheap alternatives are being sought. In recent years, industries obeying ethical implications (e.g., Mine Waste Directive, 2006/21/EC ) and/or other international official environmental agreements (e.g., Paris agreement (COP21), “European Green Deal” ) have invested in improved mining technologies and the development of waste treatment processes, hence facing an increasing total management cost. Many previous investigations have presented different environmental pollution problems, health risks, and other negative effects on the societies, communities, and economies derived from mining such waste deposits. ![]() These wastes include different materials, such as tailings, waste rocks (steriles), and slags, which all require appropriate treatment and management under the frame of environmental and economic sustainability. The mining activities alone produce a large amount of wastes, exceeding 100 billion tones/year, and they are responsible for about 50% of global greenhouse gas emissions. ![]() Their uses have tripled since 1970, in accordance with mining excavations and/or drilling exploitations. Nowadays, the modern way of life and human demands are strongly related to different natural resources (e.g., metallic and non-metallic minerals, fossil fuels, and biomass) and their applications in a wide range of fields. Furthermore, the color of the final samples changed from white-creamy to reddish as the content of clayey sterile materials increased in the raw mix. The results showed that the tested clayey steriles can be utilized up to 50 wt% as a secondary raw material in the production of ceramic materials (e.g., bricks) with comparable properties to the reference clay-bodies. The microstructural evolution of the final bodies was analyzed by scanning electron microscopy, which observed differences related to the addition of the steriles. The fired bodies were tested for their total linear shrinkage, apparent porosity, water absorption, bulk density, and bending strength according to the relevant standards. Characterization of the raw materials included chemical, mineralogical, and thermal analysis. Laboratory processing of the ceramics was performed by dry pressing loose powder into rectangular samples and firing at 1000 ☌ for 4 h. To assess this issue, clayey steriles were incorporated in a white clay-body at 20, 50, and 80 wt%, whereas reference samples were also formed from the individual raw materials. This study aims to contribute toward the sustainable management and use of such waste materials in line with the environmental objectives of the 2030 agenda. The objective of this study was to investigate the valorization potential of clayey overburden sterile materials from lignite-mining activities in the manufacturing of traditional ceramics. ![]()
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