Abstract: In view of the problem of high aluminum content in iron concentrate after high alumina iron ore separation at the present stage， Northeastern University has developed a new efficient amphiphilic chelation collector DTA-2， iron increase and aluminum decrease reverse flotation test was conducted using a magnetic separation concentrate after suspension roasting as research object. The results showed that at room temperature， natural pH， with DTA-2 as the collector and starch as the inhibitor， via one roughing one cleaning one scavenging reverse flotation process high-quality flotation product with TFe grade is 66.80% and Al₂O₃ grade is 3.26% can be obtained. It was found that， the internal structure of limonite is relatively loose， and there are many gangue minerals； around larger the iron oxide particles there are many alumina-based gangue minerals （larger than 1 μm）， fine-grained iron oxides and alumina-based gangue minerals are aggregated into magnetic aggregates， resulting in many impurity occur in concentrate； the coarse-grained alumina mineral particles of the concentrate have fine particles （less than 1 μm） dispersed iron oxide particles， and quartz， kaolinite， mica， feldspar minerals and iron oxide minerals entering the magnetic separation concentrate ore entrainment of particulate monomers into the concentrate results in higher levels of concentrate impurities. The practical problem of high aluminum content in magnetic iron concentrate after suspension roasting is solved by flotation method. The test results have reference significance for the study of iron and aluminum reduction of high alumina iron ore.

Key words: Iron increase and aluminum decrease, Amphoteric chelator collector DTA-2, Reverse flotation