Study On The Recovery Of Nanoparticles From Their Organic System By Using Froth Flotation

Froth flotation is one of the most broadly used separation methods in the mineral processing industry.However,so far,there are not any references on the recovery of nano-particles from organic effluent by using froth flotation.In fact,most catalytic reactions were taken place in organic reagents.The objective of this work was to recover Cu O nano-particles from their organic solution by using froth flotation.Firstly,the foam properties of different kinds of surfactant in different kinds of organic solvents with different water content were studied.The concentration of conventional typical surfactants could not be used to generate a stable foam phase in the non-polar organic solvents.Fluorocarbon surfactants could significantly improve the foam ability and stability of the system compared with hydrocarbon surfactants.Generally,the foam volume slowly increased when surfactant concentration increased to a certain value,for all surfactants in the solution.At the same concentration,the foaming ability of aromatics was better than that of alkane,while the foaming ability of glycerol was better than that of paraffin.In the same solvent,the foam properties of fluorocarbon surfactants was better than that of ordinary surfactants.Secondly,CAB was chosen as the suitable collector for recovering Cu O nano-particles from DMSO due to its good foam properties and capture performance to Cu O nano-particles.Froth flotation was carried out under the conditions of Cu O nano-particles concentration 20mg/L,CAB concentration 3.5×10^-2 mol/L,volumetric air flow rate 130 m L·min^-1,liquid loading volume 130 m L,and pore diameter of gas distributor 0.180±0.010 mm.Then the enrichment ratio and the recovery percentage of Cu O nano-particles reached as high as 20.52and 91.50%,respectively.Finally,the suitable operation conditions of the technology of froth flotation coupled ultrafiltration for recovering nano-sized TiO₂ photocatalysts were determined.The experimental result showed that under the suitable operation conditions of p H7.0,CTAB concentration 0.20 g/L,volumetric air flow rate 15m L?min^-1,and pore diameter of gas distributor 180?m,the enrichment ratio of the recovery percentage of nano-sized TiO₂photocatalysts reached as high as 22.52 and 99%,respectively.Meanwhile,the operating time of the membrane increased by 133%compared to that in independent ultrafiltration operation.Sum up,this work is expected to provide a new insight into the effective recovery of nano-catalysts from the downstream industrial effluent,and to facilitate the industrialization of froth flotation in green catalytic industry.