Relevance and significance of scientific problematics

The aim of the present project is to study the possibilities to synthesize ceramic pigments from pure and waste materials with respect to their possible use as pigments in the silicate industry. The ceramic pigments are inorganic colored finely dispersed powders which, when added to certain medium, impart specific color and change some properties. Besides their coloring ability, the ceramic pigments are resistant to atmospheric and chemical influences, high temperature, decomposing effect of silicate melts and light. These colored inorganic substances have high coefficient of refraction, they are insoluble in water and binding materials but can be dispersed within them, thus imparting certain color to them.

It is intended to focus the efforts of the team on investigation of the possibilities to utilize waste products, e.g. various catalysts used in Lukoil Neftochim Bourgas by developing ceramic materials on their basis. The other important waste material selected for the studies is biomaterial (rice husks) which will be used as source of SiO2 for the preparation of ceramic pigments. The development of blends and technological scheme for utilization of waste materials for manufacturing of ceramic materials is based on an extensive literary material and, of course on the rich experience of the team in this field.

Our special interests will be focused on the planned profound studies on the structure and mechanism of the synthesis of four types of pigments – spinel, willemite, garnet and zircon pigments using new and modern methods which will provide possibilities to find the correlation between them and develop optimal conditions for their synthesis.

Our choice to focus on the synthesis of new kinds of ceramic pigments is based on the growing importance of ceramic materials, powders and pigments, as well as the diverse possibilities for obtaining them from both traditional and waste materials, as well as their potentially wide practical use in ceramic and glass industries, e.g. coloring of ceramic tiles and other articles, mosaic tiles, coloring of glass to obtain various types of colored glasses, etc. their color palette is constantly widening with respect to production of over-glaze paints and coloring of glazes for the ceramic industry, e.g. for the tile production.

We will look at the state of research related to the four types of pigments that come to our attention – spinel, wilemite, garnet and zircon.

Willemite pigments

In recent years, researchers from many countries work on the synthesis, characterization and properties of various kinds of willemite ceramic pigments prepared from both ...

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Spinel pigments

The pigments of spinel structure are one of the first used in ceramic practice . There are two kinds of spinels – with normal (straight) and inverse structure. The spinels of the first type ...

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Garnet pigments

Garnets are natural minerals which have been known for very long time for their beautiful colors. They belong to the more complex orthosilicates with general formula ...

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Zircon pigments

Since they were first synthesized, the efforts devoted to the development of zircon pigments have been intense and continuous because the strong crystal lattice of zircon ...

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The main aims of the project are

  • Synthesis of new colors of willemite, spinel, garnet and zircon ceramic pigments, both from pure raw materials and from waste materials;
  • Demonstration of the possibility of utilization of waste products for the production of ceramic pigments;
  • Investigation and characterization of the obtained ceramic pigments of different types – willemite, spinel, garnet and zircon ceramic pigments;
  • Carrying out morphological analyses of synthesized pigments, presented in the form of powder and massive material with different composition and thermal history;
  • Characterization of synthesized pigments by X-ray analysis, DTA, IR-FT, color definition, etc.;
  • Study of the properties of the obtained ceramic pigments;
  • Performing semi-industrial tests with glazes in plant “Khan Omurtag", Shumen town.