Розробка методу отримання пористої і фільтрувальної кераміки з можливістю регулювання кількості пор, їх величини і розподілу за розмірами

• Datum: 2023
• Hauptverfasser: Дорошенко, В.С., Квасницька, Ю.Г., Максюта, І.І.
• Format: Artikel
• Sprache: Ukrainisch
• Veröffentlicht: Physico-technological Institute of Metals and Alloys 2023
• Schlagworte: пористий матеріал; кераміка; фільтр; фільтрувальна кераміка; лід; пористість; рідкий метал; вакуумування; регулювання величини пор
• Online Zugang: https://www.metalsandcasting.com/index.php/mcu/article/view/187
• Назва журналу: Metal and Casting of Ukraine

Porous materials – the basis of modern filtering and heat-shielding materials, catalyst carriers, flame arresters and sound absorbers – are made by the introduction of blowing agents, burnable additives or hollow bodies, pressing and extrusion molding. Examples of typical ceramic filters are shown and useful experience of filtering liquid metals with such filters for the foundry and metallurgical industry is noted. As analogues, the most applied methods for the production of porous and filter ceramics are analyzed and a new method for producing such ceramics with the possibility of controlling the number of pores, their size and size distribution is considered. For this, a cryotechnology for the use of granular ice as a blowing agent in ceramic products has been developed. Previously created methods of using granular ice for molding products from sand and ice mixtures served as the basis for a new cryotechnology for pore formation. One of the domestic compositions widely used in metallurgy of refractory concrete mixtures was selected as a prototype. For pore formation, granular ice was used in an amount of 8–90 % by weight of the mixture. Removal of this ice is conveniently carried out by spontaneous melting when the molded product is aged at room temperature or elevated to 40–100 °C. Also, a hydration binder (cement or gypsum) is introduced into the mixture of loose finely dispersed components, which is moistened with the melt of granular ice introduced into the mixture, and as a result of this moistening, the mixture sets and hardens to a monolithic state by the formation of crystalline hydrates. Physical models of the interaction of the mineral with water and ice are considered. When moistening and evacuating a ceramic preform, conditions are created for regulating its porosity both in terms of permeability and in the orientation of through pores.