Hydrophobization of calcite by wet method using stearic acid

Abstract

In this paper, the results of the modification of calcite with stearic acid using the wet method are presented. In the experiments, natural limestone with a high content of calcite (greater than 95 %) was used as the starting material. The calcite surface was modified with different amounts of stearic acid - 1, 2, 3 and 4 %. The products were haracterized by thermal analysis (DTA/TGA), polarization microscopy, IR analysis and by the evaluation of a floating test. The results of the floating test showed that hydrophobicity of the calcite surface increased with increasing the amount of stearic acid on the calcite surface and that the hydrophobicity reached over 99 % when the concentration of stearic acid was 2 %. Thermal analysis showed that at initial concentrations of stearic acid of 2 %, surfactant molecules are chemisorbed at calcite surface.