Application of chemical trated illite clay for development of ceramics products

Abstract

The chemically treatment by alkali solutions of illite clay, so-called geopolymer method, were studied to show the impact on changes of structure and crystalline phases composition of treated not dehydroxylated illite Quarternary clay, as well as ceramic properties and compressive strength of sintered respective ceramic samples. The degree of activating process were followed by FTIR-spectra, X-ray diffraction and differencial thermal analysis. The low temperature ceramic product was achieved by sintering of alkali solution (KOH or NaOH 1M, 3M, 4M and 6M) activated clay samples in temperature range from 100°C to 700°C . Sintered ceramic samples were characterized by compressive strength, total porosity, bulk density and shrinkage.It is shown that treatment of the illite Quarternary clay by KOH changes illite structure, but not destroyed. Main changes could be connected with changes of O-Al-OH grouping where O is associated with neighbour Si- layer That results into lowering of sintering temperature and development of amorphous (glassy) phase of sintered at 600–700 °C ceramic samples together with growing of total porosity. Consolidated at 600°C ceramic samples have the compressive strength ranged from 16–23 N.mm2. These values increases with growing of concentration of used alkali solution as well as with temperature for NaOH treated samples and is comparable with compressive strength for the respective ceramic products sintered at 900 °C.