Abstract: Aiming at the technical problems of high energy consumption and poor separation effect in the flotation process of diasporic bauxite with high silicon content and low Al/Si ratio,a new anionic collector,linseed oil-based citrate (NMZ),was synthesized by citric acid esterification modification using linseed oil as raw material.On this basis,with NMZ as the collector, single-factor experiments were carried out to investigate the effects of grinding fineness,collector dosage,depressant dosage and pulp pH on the desilication effect of direct flotation at room temperature.The results showed that under the conditions of grind ing fineness (-0.038 mm accounting for 80%),pulp pH of 10,depressant Na2 SiO3 dosage of 600 g/t and NMZ dosage of 1 000 g/t,the flotation index of concentrate with Al2 O3 grade of 57.75%,recovery rate of 64.65% and Al/Si ratio of 4.44 was obtained by adopting the closed-circuit flotation process of "one roughing,two cleaning and one scavenging".The Al/Si ratio of the flotation concentrate meets the requirements of DLK4-45 industrial standard.Mechanism analysis showed that NMZ was se lectively attached to the surface of diaspore through chemical adsorption,which significantly improved its hydrophobicity;while its adsorption capacity on the surface of kaolinite was extremely weak,thus realizing the separation of aluminum and silicon.