Influence of lithium oxide as auxiliary flux on the properties of triaxial porcelain bodies

High-alumina porcelain with the addition of a Li2O-bearing fluxing agent

“…The results show that the densification process of the bodies is enhanced by the presence of Li 2 O, in a similar way to that reported for triaxial porcelain bodies 10 and bodies for porcelain stoneware tiles. 11 …”

“…8 Bodies of electrical porcelain with a fairly high thermal shock resistance and mechanical strength were developed using 18.5-20.5 wt.% of spodumene and firing at 1380 • C. 9 Good properties for tableware porcelains were attained when the Li 2 O content did not exceed 1.5 wt.%, and these compositions matured at temperatures 100-120 • C lower than standard, triaxial porcelain formulations. 10 The presence of spodumene, when 10 wt.% was added as a partial replacement for sodium feldspar, reduced the firing temperature and the shrinkage of the body mixes for stoneware tiles. 11 The use of lithium-bearing minerals as a liquid-phase sintering aid has also been investigated in other types of ceramics, for example, in mullite ceramics, 12,13 to lower the firing temperature and in alumina ceramics 14 to improve the thermal shock resistance.…”

Rocha com espodumênio como fundente para massas cerâmicas tradicionais

“…Porcelanas triaxias foram analisadas, empregando-se, primeiramente, carbonato de lítio e, num segundo momento, rochas contendo espodumênio. Os autores conseguiram uma redução de 100-120 ºC na temperatura de gresificação e concluíram que os teores de Li 2 O não devem exceder ~1,5%, para não se perder em densificação das peças [14]. O uso de espodumênio, com aporte de 1 a 1,6% de Li 2 O à massa, mostrou-se benéfico para produção de porcelanas de alta alumina, com ganho de densificação, resistência mecânica e diminuição da temperatura de queima [15].…”

Development of a multipurpose tile body: Phase and microstructural development

“…According to available studies in the literature, it is the current trend to employ flux-forming additives, both natural (feldspars, nepheline syenite, zeolites, spodumene, etc.) [8][9][10][11][12] and synthetic (including industrial wastes such as waste glass and fly ash) in order to reduce the peak firing temperature and soaking time of triaxial whiteware bodies and thereby reducing the cost of energy without compromising productivity and product quality. [13][14][15][16][17] These additives may, however, produce a rapid rise in the amount of liquid phase in a short time-temperature interval during sintering, thus providing a narrow firing range and a risk of pyroplastic deformation to the ware unless a careful control of formulations is achieved.…”