METALLIZED GLAZES FOR THE DECORATION OF PORCELAIN STONEWARE USING RAW MATERIALS OF THE REPUBLIC OF BELARUS

Abstract

The aim of this research was to study the possibility of obtaining metallic (metallized) raw glazes for porcelain stoneware using the raw materials of the Republic of Belarus. Fusible clay, quartz sand, dolomite, kaolin and copper oxide were used to prepare the glazes. The glazed porcelain stoneware obtained under the industrial conditions of Berezastroimaterialy JSC had dark grey surface with a metallic appearance. The research on the physico-chemical properties of the synthesized samples was carried out under the requirements of existing international standards. The temperature coefficient of linear expansion of glazes was (65.9–73.4)∙10–7 K–1, resistance to surface abrasion (PEI) – 1–2, resistance to thermal shock – 150±5 °C. The structure of glaze coatings was characterized by X-ray diffraction analysis and scanning electron microscopy. The glassy matrix was established to be the predominant phase. Anorthite and tenorite were the crystalline components. Their amount varied depending on the glaze composition. Due to the crystalline phases, glazed porcelain stoneware has a relatively high degree of resistance to surface abrasion. A hot-stage microscope and differential scanning calorimeter were used to study the melting behavior of the experimental glazes. The characteristic temperatures (sintering, sphere, half-sphere, fusion), as well as the contact angle and shrinkage of glazes in the temperature range of 500–1400 ℃ were determined. It was found that an increase in the content of copper oxide from 12.5 to 22.5 % contributes to a decrease in the sintering temperature by 10–50 ℃. However, the prevailing influence on the surface tension of the glazes at temperatures 1050–1200 °C had the percentage of dolomite. For citation: Shymanskaya H.M., Popov R.Yu., Pospelov A.V. Metallized glazes for the decoration of porcelain stoneware using raw materials of the Republic of Belarus. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 6. P. 69-75. DOI: 10.6060/ivkkt.20236606.6808.