Fundamental Study on the Recovery of Lithium Niobate from Slicing Dust by Flotation Method

Abstract

In order to recover lithium niobate (LN) from slicing dust, flotation separation of YAG from green carborundum (GC) has been investigated by using dodecylammonium acetate (DAA) as a collector.
The zeta potential of LN was negative at pH above 2.8 in the presence of potassium nitrate. The floatability of LN with DAA was high in the weakly acidic to the alkaline pH range and decreased remarkably with decreasing pH in the pH range less than 4. The floatability of LN could not be activated with multivalent anions, such as sulfate ions, but it was activated by fluoride ions, resulting in high flotation recovery in the acidic pH range. The activation with fluoride ions may be caused not only by the increase in negative charge on LN surface (enhancement of electrostatic adsorption of DAA), but also by the chemical interaction between fluoride ions adsorbed specifically and DAA. LN was selectively floated from GC by using corn starch as a depressant in the presence of fluoride ions at pH 2 to 4.