Abstract: In this inverstigation,reverse flotation de-silicate experiments have been conducted on iron ores with new cationic collectors.The test results indicated that the collector(CS ₂∶CS ₁=2)is equal to the dodecylamine,but the selectivity is better in the range of pH 6～12.The reverse flotation tests on the magnetic concentrate have also shown that the new combination collector obtains the equal iron concentrate grade with dodecylamine,but the iron recovery increases 8.32%.The combination collector also have good adaptabilition to the hard water,the iron concentrate grade can still keeps above 69%,and the recovery keeps above 90%.