Abstract: To achieve efficient purification and preparation of high-purity iron concentrate,magnetite and quartz were selected
as the research objects. Through pure mineral flotation,artificial mixed ore flotation,and actual ore flotation tests,the optimal
reagent combination and flotation process conditions were determined. The selective adsorption mechanism of the reagents
was investigated using infrared spectroscopy,Zeta potential measurements,and contact angle analysis. In the pure mineral flotation
tests,all four compounded cationic collectors significantly affected the flotation behavior of both magnetite and quartz. Among
them,collector KDL2 exhibited the best performance at pH=6 and a dosage of 150 mg/ L,achieving the maximum recovery
difference of 65. 16 percentage points between magnetite and quartz. In the artificial mixed ore tests,KDL2 upgraded the
TFe grade of the concentrate to 70. 31%,meeting the requirement for high-purity iron concentrate. For the actual ore,a "one
roughing,one cleaning" flowsheet under conditions of 90% passing -0. 074 mm grind size,pH=6,and KDL2 dosage of 1 000
g/ t yielded a high-purity iron concentrate with a TFe grade of 70. 75% and a recovery of 63. 13%. Infrared analysis indicated
that KDL2 primarily interacted with the quartz surface via hydrogen bonding,while only weak physical adsorption occurred on
the magnetite surface. Zeta potential measurements showed that KDL2 shifted the isoelectric point of quartz by 2. 98 units,compared
to only 0. 60 for magnetite. Contact angle results revealed that KDL2 increased the contact angle of quartz to 72. 66°,significantly
enhancing its surface hydrophobicity,whereas the contact angle of magnetite increased only to 24. 12°. These results
demonstrate that the compounded cationic collector KDL2 possesses excellent selective adsorption capability,enabling effective
separation of magnetite from gangue quartz,substantially upgrading iron concentrate grade,and satisfying the production requirements
for high-purity iron concentrate. This study provides theoretical support and technical reference for enhancing magnetite
concentrate grade and achieving efficient reverse flotation purification of high-purity iron concentrate.

Key words: magnetite,cationic collector,reverse flotation,high purity iron concentrate