Low-cost zeolitic rocks are promising substitutes for feldspathic .uxes in ceramic bodies, since their fusibility, modest hardness and high cation exchange capacity (CEC) should improve grinding and sintering. Five large-scale Italian deposits of natural zeolites with di.erent mineralogy were characterised and tested in porcelain stoneware bodies. Their behaviour during processing was appraised and compared with that of zeolite-free bodies. Zeolites increased the slip viscosity during wet grinding, causing a coarser grain size distribution and consequently some drawbacks in both un.red and .red tiles. After overcoming this hindrance by dry grinding of zeolite rocks, the technological behaviour of zeolite-bearing tiles appear to be similar to that of current porcelain stoneware, though with larger .ring shrinkage and residual closed porosity.
Influence of zeolites on sintering and technological properties of porcelain stoneware tiles.
Dondi M;Guarini G;
2003
Abstract
Low-cost zeolitic rocks are promising substitutes for feldspathic .uxes in ceramic bodies, since their fusibility, modest hardness and high cation exchange capacity (CEC) should improve grinding and sintering. Five large-scale Italian deposits of natural zeolites with di.erent mineralogy were characterised and tested in porcelain stoneware bodies. Their behaviour during processing was appraised and compared with that of zeolite-free bodies. Zeolites increased the slip viscosity during wet grinding, causing a coarser grain size distribution and consequently some drawbacks in both un.red and .red tiles. After overcoming this hindrance by dry grinding of zeolite rocks, the technological behaviour of zeolite-bearing tiles appear to be similar to that of current porcelain stoneware, though with larger .ring shrinkage and residual closed porosity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
