engleski

The influence of Tiron on the rheological properties of alumina suspensions which contain waste alumina powder

Ceramic materials are already a well-known and widely used group of technical materials. Convenient properties such as density and strength, high hardness as well as high temperature and corrosion resistance provide the ability to use ceramic materials for many technical purposes. During the green machining of the green body, a certain amount of waste ceramic powder is generated which remains unused. In addition, the waste ceramic powder should be disposed as a non-hazardous waste in a legally prescribed manner. In this paper, the commercial dispersant ‘Tiron’ is investigated for the stabilization of highly concentrated alumina suspensions with three different composition of waste (secondary) alumina powder. The dispersant amount was varied and the rheological curves were recorded, in order to determine the optimal amount of the dispersant. The amount of the dispersant required for the minimum viscosity to obtain stable alumina suspensions with different addition of waste alumina powder was determined to be in range from 0.05 to 0.06 expressed on dry weight basis (dwb %) of alumina powder for each suspension. The viscosity of all suspensions suggests that the waste alumina powder may be used to prepare new ceramic products, like less complex shapes produced via the direct casting process. According to the measured viscosity, the amount of waste alumina powder of 15 % wt., with the optimal amount of the dispersant, indicates possible applications in the production of new ceramics products, with acceptable properties.

alumina suspensions, waste alumina, slip casting, rheology

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