In　this　study,　the　effects　of　common　ions,　especially　Ca2+,　on　the　reverse　flotation　of　fluorapatite　and　dolomite　in　acidic　conditions　with　NaOL　collector　were　investigated　using　micro-flotation,　zeta　potential,　contact　angle,　adsorption　analysis,　Fourier　transform　infrared　spectroscopy,　X-ray　photoelectron　spectroscopy　and　density　functional　theory-based　first　principal　calculations.　It　is　found　that　the　dolomite　flotation　recovery　was　enhanced　and　the　fluorapatite　flotation　was　depressed　by　the　addition　of　CaCl2　at　pH　5.　For　dolomite,　in　the　presence　of　CaCl2,　the　solubility　of　metal　ions　was　increased,　especially　for　Ca2+.　The　Ca　and　Mg　sites　exposed　on　the　dolomite　surface,　increased　the　NaOL　adsorption,　thus,　enhancing　the　dolomite　flotation.　However,　the　formation　of　Ca(H2PO4)(2)　species　on　fluorapatite　surface　inhibit　its　flotation.