VOL 86, No. 3 (2013)

The features of the coagulation structure and technological properties of slip masses for casting ceramics on stands in gypsum molds and under external pressure in polymer molds are shown. The compositions of the masses are given, which make it possible to comprehensively solve the problems of optimizing the characteristics of water systems during the differentiation of casting methods and the structure of porcelain during firing.

The migration of ions of heavy metals (Zn ²⁺, Cu ²⁺, Cr ³⁺, Cr ⁶⁺, Ni ²⁺, Fe ²⁺ and Fe ³⁺) from ceramic bricks containing wastewater sludge from electroplating industries. The regularities of the migration of chemical elements under the influence of various factors (temperature and exposure time, pH of the model medium) in relation to the charge and chemical composition of the masses, as well as the structure and phase composition of materials have been established. The optimal content of sewage sludge in the composition of the masses for obtaining ceramic bricks, which fully meets the requirements of regulatory documents for the migration of chemical elements, has been determined.

The introduction of plasticizers into ceramic masses allows to facilitate the extrusion process, increase the speed of the bar and increase productivity. It is possible with a lower molding moisture to obtain products with a good appearance. The use of grinding intensifiers contributes to a significant reduction in the time for grinding silicate materials and in energy consumption.

According to its physical, chemical and decorative properties, stone casting can be successfully used for the manufacture of internal and external cladding of buildings and structures, paving details, architectural and construction elements, art products and sculptural compositions, as well as in industrial construction under the influence of an aggressive environment.

Studies have shown that clay with a high content of quartz SiO ₂ = 65 - 72%, calcium oxide CaO = 10 - 15% and Fe ₂ O < sub> 3 = 8 - 12%. Due to the crystallization of mullite in the samples under study, the bricks have increased durability. Wollastonite, formed due to the increased content of CaO in the clay, creates a dense framework that prevents changes in the previous volume, i.e. noticeably reduces stresses and shrinkage of ceramic products.

Studied the mineral composition of clay raw materials from 48 deposits of Ukraine, which have industrial application. The influence of the mineral composition of clays on the properties of ceramic materials obtained on their basis has been established. Diagrams are plotted in which areas of the mineral composition of clays with a mass fraction of free quartz from 30 to 50%, suitable for the production of wall and facade ceramics, obtained in the firing temperature range of 950 - 1050 ° C, are highlighted.

The possibility of creating an energy-technological unit on the basis of a kiln for a more complete use of the resulting secondary energy resources, as well as the feasibility of using an exergy method for assessing the efficiency of kilns and recycling of secondary heat, which is a promising direction in solving energy saving issues for ceramic industries, is shown.

In the system of materials datolite - perlite - cullet, low-melting jade glazes with a firing temperature of 950 - 1000 ° C were obtained. The conditions for the formation of high-quality coatings have been established: preliminary firing of datolite and perlite, compliance with the inequality B ₂ O ₃ / Al ₂ O _{3 in the glaze composition}> 2.5, ultrafine slurry.