New perspectives in iron ore flotation: Use of collector reagents without depressants in reverse cationic flotation of quartz

Abstract

The reverse flotation of the iron ore with etheramine collector is significantly impacted when the iron-bearing silicates and the kaolinite are present in the silicates gangue mineral complex. This paper aims to propose a new amidoamine collector N-[3-(Dimethylamino)propyl]dodecanamide for iron ore reverse flotation with a potential of removing the iron oxides depressant. The contact angle and electrophoretic mobility measurements as well as the flotation experiments were performed on the pure quartz, kaolinite and hematite samples to compare its effect with the etheramine which is widely used as collector in reverse flotation of iron ores. Infrared spectroscopy was performed to study the adsorption of the amidoamine collector on the surface of the minerals studied.Amidoamine collector showed a significant selectivity towards quartz while the flotation of hematite and kaolinite were inhibited at pH 10 without the presence of a depressor. A total floatability of quartz was explained by increased contact angle from 10° to about 50° without impacting significantly the contact angle measured on the hematite (9.4° to 17°). Surface hindrance effect caused by the structure of the N-[3-(Dimethylamino)propyl]dodecanamide collector on the hematite surface is the most suitable hypothesis concerning the high selectivity regarding the iron ore reverse flotation process.