Abstract: There are problems of complex technology，serious equipment corrosion，much discharge of three wastes in extracting rare earth from rare earth concentrate.To green and efficiently use rare earth resources，by roasting rare earth concentrate after adding calcium hydroxide，and influence of inhibitor type on floatability of roasted rare earth concentrate (presented by REO single ore) in sodium oleate flotation system were studied.The effect of different kinds of depressants on REO flotation behavior were investigated by using sodium pyrophosphate，calgon，sodium phosphate and sodium silicate as inorganic depressants，citric acid，lactic acid and tartaric acid as organic small molecule depressants，corn starch，carboxymethylcellulose sodium，cationic starch and sodium carboxymethyl starch as organic polymer depressants.The results show that citric acid and sodium pyrophosphate have obvious depression on REO flotation among three types of depressants，calgon and sodium phosphate have weak depression.Sodium pyrophosphate has strong depression at all research pH range，but the depression of citric acid was affected by pH.When pH<8，citric acid has strong depression，but it has weak depression on REO at 8

Key words: Roasting, REO concentrate, Floatability, Citric acid, Sodium pyrophosphate