Concentration of carbonate admixture from opalized tuff into one separate fraction

Abstract

White opalized tuff (from the Strmoš locality, Probištip), as a raw silicate amorphous material,contains some quantity of admixtures. The total quantity of admixtures amounts is about 8% mass. Мine powdery ingredientsare homogeneously distributed into the basic silicate mass. Carbonate material is a significant part of presentadmixtures, and it is possible to be separated with controlled milling. Milling parameters (type and time of milling)enables to concentrate the present CaCO3 in granulometric fraction <0.032 m, after 30 min. milling. Reliableevidence about aforementioned separation is shown with simultaneous view of the results of silicate chemical analysis,DT/TG analysis (750–850oC), and sieve-analysis. From the X-ray analysis it is evident that the present carbonatematerial exists in crypto crystal to amorphous state. The space where CaCO3 is hidden, presents the place betweenbasic silicate particles inside the groups, generally with dimensions about 40 to 60 m. The concentration of CaCO3appears when this particle group goes to the process of disintegration.