A feasible strategy for depressant-free flotation separation of siderite from magnesiohornblende using a highly selective collector

Abstract

At present, efficient separation of siderite from Mg-Fe-Al-bearing silicate minerals, especially magnesiohornblende, by froth flotation using conventional collectors is difficult because they have similar surface properties. In this work, polyoxyethylenated laurylamine with five oxyethylene units (POE-5 laurylamine) was used as a magnesiohornblende collector for rejecting magnesiohornblende from siderite effectively during reverse flotation. Batch flotation tests illustrated that POE-5 laurylamine exhibited an outstanding collecting capacity and a high selectivity for the magnesiohornblende flotation rather than the siderite flotation. Much better floatability of magnesiohornblende than siderite was attributed to the larger amounts of POE-5 laurylamine adsorbed onto magnesiohornblende, as demonstrated by XPS results. FTIR and zeta potential measurements further revealed that the combination of hydrogen bonding and electrostatic attraction caused POE-5 laurylamine to strongly attach on the surface of magnesiohornblende compared to siderite, which favored the selective flotation of magnesiohornblende. Consequently, the efficient depressant-free flotation separation of siderite and magnesiohornblende was realized with 0.30 mM POE-5 laurylamine at pH 6.35, in which 92.88% of magnesiohornblende was effectively removed, combined with a high siderite recovery of 95.44% in the flotation concentrate. Therefore, POE-5 laurylamine can be chosen as a potential collector for efficiently recovering siderite from magnesiohornblende during reverse flotation.