Based on the modern ideas about environmental protection, this paper reports a study into the utilization of water-treated waste from heavy metals (using copper(II) compounds as an example) for the manufacture of ceramic building materials. The examined clay minerals from local deposits and the optimal conditions for their heat treatment (at 1,100 °C) have been proposed for the sorption removal of pollutants of inorganic origin from wastewater. The use of wastewater after its treatment makes it possible to address several tasks at the same time: to protect the environment from pollution by technological wastewater, as well as to reuse wastewater in order to resolve the issue of water scarcity. Ceramic building materials were manufactured based on water purification waste (in the amount of 5 %) and clay raw materials. Their structural-mechanical and physicochemical characteristics have been comprehensively studied. Sintering processes begin at lower temperatures, which is why, with an increase in the annealing temperature to 1,000 °C and higher, their strength rapidly decreases. In the temperature range of 600‒1,100 °C, there are possibilities to apply ceramic technology to immobilize heavy metals in ceramic matrices. The prospect of utilizing water purification waste in the technological process of manufacturing inorganic ceramic materials has been shown. The safety of the building materials, manufactured by leaching pollutants from the ceramic samples using various aggressive environments (leaching to 6.4 %, 0.083 mg·cm2/day) has been investigated. The high strength and degree of the copper ion fixation in the structure of polymineral clay have been confirmed while secondary environmental pollution is almost absent

The object of research is low-melting clays of the Kyiv region (Ukraine). The work is devoted to the study of obtaining ceramic materials resistant to low temperatures. Frost resistance is one of the most important characteristics for regions in which ceramic materials are used with frequent temperature transitions through 0 °C. The production of frost-resistant ceramic wall materials is determined by the type of raw materials and technological production parameters. The main technological methods for increasing frost resistance are: the use of less dispersed clays; batch homogenization; formation of raw material without textural defects and prevention of cracks during drying and firing. The work shows that the existing methods for increasing frost resistance can be implemented by reducing water absorption due to the creation of a microporous structure with predominantly closed pores by increased pressure of a semi-dry method of formation. An increase in the pressing pressure leads to an increase in the number of contacts of the molecules of the ceramic mass at the stage of formation. Due to this, the strength of the molded samples at a pressing pressure of more than 30 MPa is higher compared to samples molded by the plastic method. It was also found that an increase in the pressing pressure makes it possible to speed up the drying process of ceramic products, reducing energy consumption for their production. Due to an increase in the pressing pressure to 50 MPa, the strength of samples obtained by semi-dry pressing is 55.4 MPa, while for samples during plastic formation it is 22.9 MPa. Water absorption, on the contrary, for dry pressing is 9.3 %, while for plastic pressing it is 12.2 % at a firing temperature of 1000 °C. It is shown that increasing the pressing pressure is an effective way to improve the quality of ceramic materials based on local low-plasticity clay raw materials. Saving natural and energy resources, developing new sources of raw materials and comprehensive improvement of products with environmental friendliness of production remain important today.

The object of research is the physical and chemical processes of forming the structure and properties of ceramic masses based on local low-melting clay raw materials of the Kyiv region of Ukraine by adjusting the chemical and mineralogical composition and technological regimes. Building ceramic materials are durable, ecological and natural. They provide increased comfort of buildings due to the creation of a favorable temperature and humidity climate of the premises. When using low-melting raw materials in production, there is a need to develop ways and methods to improve the quality of building ceramics. The efficiency of the manufacture of ceramic products largely depends on the processes that occur during drying. This is of crucial importance and affects the quality of finished products and accounts for 10–12 % of the total cost of finished products. Polymineral clay compositions with the addition of natural mineral raw materials are mainly used for the production of construction materials. For effective use of these materials, it is necessary to study their technological properties. Therefore, the question of researching masses based on low-melting clays with high sensitivity to drying, and the use of zeolite-containing mineral rock as an admixture is relevant. This will allow expanding the nomenclature of building ceramics products. Modern physico-chemical and physico-technological methods of research of raw materials and masses based on them during drying were used to solve the task of obtaining ceramic material from local raw materials with the use of a non-deficient natural additive of zeolite-containing rock as an admixture. The conducted studies indicate that the addition of zeolite-containing rock can be used to improve the drying properties of ceramic masses based on low-melting clays. Adding admixture of zeolite-containing rock also increased the compressive strength of finished products, which ensures defect-free transportation of products to other technological operations.

The object of the study is the physical and chemical processes of formation of the structure and properties, intensification of sintering of ceramic masses based on local raw materials (Krynichanska low-melting clay raw materials of the Kyiv region, Ukraine) by regulating the chemical and mineralogical composition and technological regimes. When choosing clay raw materials for specific ceramic technologies, it is necessary to be guided by a comprehensive assessment of the physicochemical properties of clay rock. These can be the granulometric and material composition, including the chemical and mineralogical composition of the clay and impurity components, the presence of amorphous material. The state of order in the structure of clay-forming minerals is also important, the knowledge of which makes it possible to determine the ways of regulating the basic technological properties of clay rock in order to bring them to the required level. Among physical and mechanical parameters, mechanical strength is one of the main criteria for determining the suitability of raw materials for the production of building ceramics. The conducted studies have shown that with an increase in the amount of rotten stone additive introduced from 10 to 20 % of low-melting clay, the mechanical strength of ceramic samples in compression and bending increases. The introduction of rotten stone additive provides an increase in the coefficient of sensitivity to drying low-melting clay raw materials, which has a positive effect on the crack resistance of raw bricks when drying clay rock in order to bring them to the required level. The use of silica materials in the composition of ceramic masses based on low-melting clays as an additive to improve the physical and mechanical characteristics of the finished product has shown its effectiveness. This can be explained by the fact that the nature of the interaction of silica additives, which was used as rotten stone, differs from the interaction of clay minerals present in ceramic raw materials with water. Since silica exists in rotten stone in the form of amorphous silica gel, it helps to improve the structure of clay, makes it monolithic, increasing mechanical strength. The impurities of low-melting oxides, which are part of the rotten stone, contribute to the formation of low-melting eutectic, reducing the refractoriness of amorphous silica and have a positive effect on the sintering process, forming a glass phase.