Use of fatty acids with an ethoxylated alcohol for apatite flotation from old fine-grained tailings

This work presents the results obtained during flotation of fine-grained apatite-bearing tailings provided from the Kovdor concentration plant in a laboratory cell and a pilot-scale column. Flotation studies were conducted on a sample containing >85 % particles passing 36 mu m by using tall oil fatty acids in combination with polyoxy-ethylene cetyl ether (2 EO groups) as an alternative for nonylphenol ethoxylates. 45.5 % P2O5 recovery to a concentrate grade of 31.2 % P2O5 from 9.1 % P2O5 feed was achieved after rougher and one cleaner stage in a pilot-scale column using the mixed collector with phosphate modifier and starch as depressor.