This paper investigates the surface modification of calcite from the Nigde region of Turkey with sodium oleate (SDO) as a modification agent, which is incorporated into the calcite with wet ultra-fine grinding in a laboratory stirred ball mill. The effect of surface modification is evaluated by a floating test, which measures the active ratio (AR), fourier transform infrared spectrometry (FT/IR) and thermogravity analyses (TG-DTA). The results indicate that the hydrophilic surface of calcite becomes hydrophobic after the incorporation of SOD through wet-stirred ball milling. (c) 2011 Elsevier B.V. All rights reserved.