Flotation and adsorption characteristics of the most commonly used cationic and anionic collectors with high grade orthoclase were investigated through the electrokinetic potential measurement, microflotation, Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) studies. According to the obtained results, orthoclase had high flotation recovery with amine and oleic acid based (OAB) collector at certain pH ranges no flotation response was observed with petroleum sulfonate at different pHs. In contrast to the flotation recovery differences, the electrokinetic potential measurements, FTIR and AFM analyses presented similar adsorption characteristics for all collectors. The results of electrokinetic potential tests showed that amine had a strong influence on the zeta potential of orthoclase. While amine turned the zeta potentials of orthoclase from negative to positive, sulfonate and OAB collector provided slightly more negative zeta potentials at certain pHs. In the case of FTIR and AFM analyses, each collector-treated orthoclase (CTO) sample displayed similar characteristic FTIR bands of CH2 group and micro topographical collector coated patches with different intensities. However, the interactions of each collector with orthoclase surfaces were altered by rinsing with acetone indicating that the interactions were mostly through the electrostatic forces and/or hydrogen bonding.