Investigation the calcite hydrophobisation of different grain sizes

This paper presents the investigations of possibility of calcite hydrophobisation. Two samples of calcite of different size classes from the site 'Dobar kamen', Arandjelovac, Serbia, were used in the experimental work. Modifying the surface of calcite was carried out by stearic acid with 'dry' method. Concentrations of stearic acid in the modifying method were as follows: 0.3, 0.5, 0.8, 0.9, 1, 2, 2.5, 3 and 4%. The results showed that a complete hydrophobicity (I0=99.9%) of calcite sample with the medium diameter (d50) 10.87 μm was achieved at concentration of stearic acid of 0.8%, while for the sample with the mean grain diameter (d50) of 29.14 μm, it was achieved at concentration of stearic acid of 3%. These results were confirmed by the microscopic analysis.