Application of galvanic sludge for modification of cerium-containing ceramics with high thermal and chemical resistance
Abstract
Application of galvanic sludge for modification of cerium-containing ceramics with high thermal and chemical resistance
Incoming article date: 11.06.2024The paper presents the results of a study of the effect of galvanic sludge on the basic performance properties of special-purpose ceramics. The basis of the composition of the charge is low-plastic clay, and the functional additives in its composition are boric acid and cerium oxide. Ceramics are produced by semi-dry pressing at a pressure of 15 MPa and a maximum firing temperature of 1050 ° C. It has been established that galvanic sludge decomposes into calcium and heavy metal oxides, carbon dioxide and water vapor during firing. The oxides formed during liquid-phase sintering are part of the vitreous phase, functionally modifying its characteristics. When the content of galvanic sludge in the charge is more than 5 wt. % a developed porous structure is formed in the material, which reduces its main operational characteristics. It was revealed that liquid-phase sintering provides safe immobilization of heavy metals if the content of galvanic sludge in the charge does not exceed 6 wt. %. Practical application of the charge composition, including galvanic sludge in an amount up to 5 wt. %, will increase the resistance of ceramics to high temperatures, temperature changes, acids and alkalis. The use of galvanic sludge in this area will contribute to solving the environmental problem of its processing.
Keywords: ceramics, heat resistance, chemical resistance, liquid phase sintering, galvanic sludge, low-plastic clay, cerium oxide, boric acid