Abstract: In order to solve the problem of unsatisfactory separation indicators of carbonate-containing hematite,taking siderite and hematite as the research objects and sodium cocoylglycinate + sodium oleate (SCG+NaOL) as the combined collecting agent,a systematic flotation experimental study on the efficient flotation separation of siderite and hematite was carried out. The interaction mechanism between the compound reagent and minerals was revealed through contact angle tests,Zeta potential tests,infrared spectroscopy analysis,surface tension tests and adsorption capacity tests. The results of the flotation test showed that the combined collector sodium cocoyl glycinate + sodium oleate (with a mass ratio of 7 ∶1) has good floatability for siderite but poor floatability for hematite. When the artificial mixed ore (with a mass ratio of siderite to hematite of 1 ∶4) was treated under the conditions of pH= 7 and the dosage of sodium cocoyl glycinate + sodium oleate was 100 mg / L,a foam product with a FeO content of 44. 07% and a siderite recovery rate of 71. 92% could be obtained,and the separation index was 6. 71. Compared with the starch-to-sodium oleate system,FeO grade and recovery rate of siderite increased by 6. 14 and 32. 10 percentage points respectively. Mechanism analysis indicated that the compounding of SCG and NaOL can significantly enhance the solubility of SCG. After the interaction of SCG+NaOL with the two minerals,the hydrophobicity of siderite and the hydrophilicity of hematite can be significantly improved. Meanwhile,compared with the starch +NaOL system,the SCG+NaOL reagent system is simple and can significantly improve the selectivity of siderite and hematite flotation separation. 

Key words: sodium cocoylglycinate (SCG),compounding agent,siderite,hematite,flotation separation