Preliminary studies of Bulgarian natural raw materials as possible sources for the synthesis of high-quality ceramics of the “yellow” pavers type

The results of preliminary studies of Bulgarian natural raw materials as possible sources for the synthesis of high-quality ceramics of the “yellow” pavers type are presented. For the purposes of comparative analysis, a short geological-mineralogical literature review of Bulgarian and Hungarian deposits of marl raw materials and of Bulgarian deposits of non-marl raw materials rich in magnesium is made. The capabilities of the X-ray fluorescence (XRF) analysis and the powder X-ray diffraction (PXRD) techniques for the rapid acquisition of reliable data on the phase-chemical characteristics of the investigated materials have been demonstrated. A relation is made between these characteristics and the physicochemical and mechanical properties of possibly synthesized products (color, hardness, etc.). Considerations for choosing methods for processing the primary data are presented, allowing for some simplification without affecting the reliability of the results. The latter have been analyzed and possibilities for improving the qualities of the starting raw material have been discussed in order to obtain products with desired characteristics.