Research

The aim of this project is to definitely demonstrate the possibility of synthesizing clinkers, a type of “yellow" pavers, which fully resemble the original historical pavement in Sofia in terms of composition, structure, appearance and mechanical properties. It is foreseen, after studying and characterizing different marl deposits in the country, to add up to 10% of suitable natural raw materials or industrial waste, rich in MgO and iron oxides, to the main marl clay. This will ensure the formation of the desired quantities and type of pyroxene and anorthite crystal phases, which explains the very good mechanical properties of this unique pavement. In order to improve the technological scheme, increase the quality of the products and shorten the firing times, studies to reduce the initial porosity and the fire shrinkage of the ceramics are planned. These experiments will mainly be related to study the effect of preliminary calcination of a part of raw materials. This preliminary treatment can reduce the high plasticity of the marl clays. In parallel, the possibility of obtain clicker products from industrial waste with the addition of some of the characterized marl clays will be investigated. This would make it possible to obtain new anorthite or pyroxene clinkers with improved properties and reduced firing temperature using industrial waste with a low CaO content. 

Until now, such ceramics have only been obtained from waste raw materials rich in calcium oxide and traditional clays. At the end of the project, it is planned to study the possibility to use microwave heat treatment in the production cycle. These studies are expected to show whether it is possible to further reduction of the time and cost of the production process.The project proposal is interdisciplinary and involves three partner organizations with different professional orientations. The head of the project is the only active Bulgarian scientist in the field of “materials" who is included in the lists of 2% of the best scientists in the world for 2020 and 2021. The team also includes other noticeable scientists, the winner of the award for “young scientist" in the field of “Nanosciences, new materials and technologies" in the 2021 competition of the BAS, as well as successful post-doctoral students, young scientists and students.Various research methods will be used during the the project, which is possible due to the availability of numerous scientific equipment in the participating organizations. Part of this equipment is still unique for Bulgaria.