SCIENTIFIC FOUNDATIONS AND PHYSICOCHEMICAL PROPERTIES OF CERAMIC TILES BASED ON RAW MATERIALS FROM KARAKALPAKSTAN

ABSTRACT

In this article, the possibilities of using non-traditional raw materials such as kaolin from the Uchkuduk deposit and diabases from the Keklitog deposit in the production of ceramic materials have been studied. Their physicochemical properties were determined, and the phase transition processes at high temperatures were analyzed. The analysis of the raw materials was carried out using chemical-analytical methods. During the research, opportunities for expanding the raw material base of the ceramic materials industry through the use of new local raw materials were identified.

АННОТАЦИЯ

В данной статье изучены возможности применения нетрадиционного сырья — каолина Учкудукского месторождения и диабазов месторождения Кеклитог — для получения керамических материалов. Были определены их физико-химические показатели и проанализированы процессы фазовых переходов при высоких температурах. Анализ сырья проводился с использованием химико-аналитических методов. В ходе исследования выявлены возможности расширения сырьевой базы керамической промышленности за счёт использования новых местных видов сырья.

Keywords:  igneous rock, clay, diabase, physicochemical property, chemical-analytical analysis, oxide, firing temperature, vitrification, phase, crystallization.

Ключевые слова: магматическая порода, глина, диабаз, физико-химическое свойство, химико-аналитический анализ, оксид, температура обжига, остекловывание, фаза, кристаллизация.

Introduction. Currently, in our country, one of the most important challenges is the expansion of the local raw material base and the rational use of energy resources by involving new mineral resource deposits and various industrial wastes in the production of high-quality construction ceramics. In many developed countries, the application of modern innovative technologies for producing energy-efficient ceramic products with high physico-mechanical indicators is of paramount importance for increasing productivity and competitiveness in global markets, as well as for improving the performance properties of ceramic products used in the construction industry. A thorough study of the state, quality, and compositional characteristics of natural raw materials used in the production of ceramic tiles, such as kaolin, quartz sands, diabase, and feldspar, is essential for the development of ceramic materials [5].

In the Republic of Karakalpakstan, comprehensive measures are being implemented to expand the raw material base for the construction industry, develop non-traditional promising clayey, stony, and magmatic raw material resources, utilize diabase and clayey raw materials for the production of various-purpose ceramic tiles, ensure rational use of energy and natural resources, reduce the firing temperature, identify new crystalline phases of minerals that impart the necessary technological properties to finished products, and improve their technological and performance characteristics [4].

For the experimental research, samples of Keklitog diabase from Karakalpakstan, Uchkuduk kaolin, and Tabakkum dune sands were used as the initial components, as sufficient reserves of these raw materials exist for their application in industrial production.

Research materials and methods. The development of the composition of ceramic materials based on clay and magmatic rocks, the creation of their processing technology, and the determination of their fundamental physicochemical properties were conducted experimentally using modern and conventionally accepted standard testing methods.

This research was carried out using chemical-analytical methods with the aim of determining the potential applications of the materials in the production of ceramic tiles intended for construction purposes.

Results and discussions. The chemical composition of the necessary raw materials and experimental samples for ceramic material production was determined in accordance with the requirements of GOST 27180-2019, using the standard silicate-analysis method [1]. The chemical analysis focused on studying the substance's composition, identifying the elements, their compounds, and their quantitative ratios.

Initially, the material was prepared for analysis by being crushed and ground into a powdered state [2]. In the subsequent stage, the presence of elements was identified, and the constituent components and phase properties of the substance were studied. Thereafter, through quantitative analysis, the mass or percentage share of each element was calculated (Table 1).

Table 1.

Chemical composition of the raw material samples

It was determined that the composition of Uchkuduk kaolin contains high amounts of SiO₂ and Al₂O₃ as its primary components. These specific oxides define the fundamental properties of kaolin, namely its plasticity, heat resistance, and mechanical strength. These results confirm the potential for using Uchkuduk kaolin as a high-quality raw material.

The high content of silicon oxide in the diabase indicates its potential for use in ceramic material production. Aluminum oxide enhances the product's heat resistance and thermal stability. Potassium and sodium oxides facilitate the formation of a melt at lower temperatures. The relatively low loss on ignition results in minimal gas evolution at high temperatures, which positively impacts the material's density [3].

Chemical analysis of the Tabakkum dune sand samples revealed a very high SiO₂ content, indicating that quartz is the primary mineral constituent. The presence of Al₂O₃ suggests feldspar and a small amount of clay minerals.

Overall, the chemical composition of the Tabakkum deposit dune sand is shown to be similar to that of quartz sands obtained from other deposits.

To ensure the complete decomposition of crystallization water and carbonates in these samples of kaolin, diabase, and dune sand, they were fired in a muffle furnace at a temperature of 1000 °C for 2 hours. The chemical composition and the quantities of the resulting samples after firing are presented in Table 2. The data from the table are used for formula selection, establishing a strict firing regime, and preliminary risk assessment.

Table 2.

Chemical composition of raw material components after high-temperature heating

The indicators in the table are essential for developing ceramic formulas, establishing the firing regime, and pre-evaluating the material's color, density, porosity, and mechanical properties. This is because heating to 1000 °C causes the release of water and carbonates from the sample composition (Loss on Ignition, L.O.I.), resulting in remaining values that are in a convenient state for comparison on an "oxide basis." For example, in kaolin, the table values show SiO₂ = 70.63% and Al₂O₃ = 17.73%. If we take the ratio of these two, SiO₂/Al₂O₃ ≈ 3.984, meaning the ratio of silicon to aluminum oxides is approximately 3.98:1. This indicates the kaolin's suitability for mullite formation and its contribution of clay-like properties.        

The primary indicators for Keklitog diabase in the table are SiO₂ and Al₂O₃, with a SiO₂/Al₂O₃ ≈ 3.633. The most notable aspect of the diabase is its high alkali content: Na₂O = 10.14% and K₂O = 2.01%, i.e., a total Na₂O+K₂O = 12.15%. This classifies the material as a high-grade flux former, which can lead to a significant reduction in the firing temperature for obtaining ceramic tiles.

The Tabakkum dune sand exhibits properties of nearly pure quartz. It functions excellently as a filler and structure-forming mineral, providing volumetric stability and strength against shrinkage during firing to the material.

During the heating process to 1000 °C, the structural water in kaolin is removed through dehydroxylation, and the kaolin transforms into metakaolin; at higher temperatures, the mullite phase appears, which increases the product's heat resistance and mechanical strength. Carbonates, on the other hand, decompose, releasing CO₂. In Keklitog diabase, it forms a glassy phase, facilitating the sintering process and lowering its temperature.

Conclusion. This research work provides a detailed account of how the raw materials from the territory of the Republic of Karakalpakstan, based on their chemical-mineralogical composition, can be used in the production of construction ceramic materials. Furthermore, based on the analysis results, it was determined that they comply with GOST requirements and their composition is similar to that of traditional raw materials.

References:

1. GOST 27180-2019. Ceramic tiles. Test methods. – Retrived from: https://meganorm.ru/Data2/1/4293726/4293726326.pdf (accessed date: 05.09.2025) [in Russian].
2. GOST 9169-75. Clay raw materials for the ceramic industry. 1975. – Retrived from: https://meganorm.ru/Data/255/25588.pdf (accessed date: 15.09.2025) [in Russian].
3. Janabaev O.O., Eminov A.M., Niyazova Sh.M., Kalbaev B.A. Physico-chemical studies of diabases of karakalpakstan in the production of silicate construction materials // The American Journal of Applied Sciences. – 2024. – Vol. 6 (06). – Pp. 22–27. https://doi.org/10.37547/tajas/Volume06Issue06-05
4. Kalbaev B.A., Eminov A.M., Janabaev O.O., Toreniyazov M.A.  Study  of Shomishkul  kaolin  for  producing  ceramic  materials  //  E3S  Web  of Conferences. – 2024. – Pp. 02005 https://doi.org/10.1051/e3sconf/202449402005
5. Yangi O‘zbekiston tarraqiyot strategiyasi // O‘zbekiston nashiriyoti. – Toshkent-2023.