Common and Different in Latvian Clay Minerals

Abstract

Clays are materials consisting of clay minerals and non-clay minerals. Some applications allow to use raw clay others require to separate clay minerals from non-clay minerals. Clay mineral fraction is considered to be a nanofraction. Description and characterization of 3 different Latvian clay nanosized minerals from 3 different geological periods (clay Liepa from Devonian period, clay Vadakste from Triassic period and clay Apriki from Quaternary period) are summarized. The main mineral in these clays is illite, however the presence of kaolinite is observed and its quantity depends on geological period in which clays formed. Nanosized clay mineral particles were obtained using sedimentation method. Comparison of mineralogical composition, BET nitrogen adsorption, zeta potential, DTA/TG analysis and FTIR spectra is given. XRD phase analysis results were very close to each other and shows that mineral of illite is more than that of kaolinite. BET nitrogen adsorption data shows that clay minerals of Apriki has the highest specific surface area (81 m2/g), whereas clay minerals of Vadakste has it the lowest (43 m2/g). Zeta potential values for clay minerals Apriki, Liepa and Vadakste are-40.9 mV, -49.6 mV and-43.0 mV, respectively. DTA analysis and FTIR spectra show similar tendencies for all 3 clay minerals.