Mitigating the negative effects of feldspar slime on spodumene flotation using mixed anionic/cationic collector

Due to the prevalent weathering, spodumene flotation is often susceptible to feldspar slime. In this study, the effect of feldspar slime on spodumene flotation in the NaOL and NaOL/DDA systems was studied. The microflotation tests showed that the negative effect of feldspar slime on spodumene flotation could be reduced by using the mixed NaOL/DDA collector with mole ratio of 9/1. The scanning electron microscopic images and the adsorption test results indicated that the decrease of spodumene recovery was attributed to collector consumption by feldspar slime. The mechanism was analyzed by ways of surface tension measurement, atomic force microscopic (AFM) observation and bubble attachment measurements, and the results showed that compared with NaOL alone, the mixed NaOL/DDA collector exhibited a better surface activity owing to a lower value of critical micelle concentration (CMC). The 'spots' formed on spodumene surface were thicker, and the formation of TPC was more likely. In addition, the bubble size was smaller and the bubble-particle adhesion was more possibly to occur in the NaOL/DDA system.