Flotation Performance And Mechanism Of A Gemini Surfactant On Lepidolite

Lithium,as an important energy metal,is widely used in all walks of life and is known as"industrial monosodium glutamate"and"metal promoting world progress".In view of the characteristics of lepidolite resources and the difficulty in separating lepidolite from feldspar and quartz,three quaternary ammonium Gemini surfactants(codes BAB-12,BAB-14,BAB-16)with different carbon chain lengths containing amphiphilic/hydrophobic groups were prepared,and the effect of their combination with different anionic collectors on the flotation behavior of lepidolite,potassium feldspar and quartz was further investigated.At the same time,the interface mechanism of Gemini type collector and combined collector on minerals was investigated by infrared spectrum analysis,adsorption measurement,zeta potential and contact angle test.The research results are as follows:The results of pure mineral flotation test show that:Compared with the traditional cationic collector dodecylamine(DDA),Gemini collector has a better flotation effect on lepidolite,and its collection capacity is ranked as BAB-12>BAB-14>DDA>BAB-16.At the same time,the reason why BAB-12 has better performance than DDA is explained at the molecular level through quantum chemical calculation:BAB-12 is dominated by double–CH2N~+group,which has stronger chemical reaction and electrostatic adsorption;The combination of sodium dodecyl sulfate/sodium oleate(Na OL)/sodium petroleum sulfonate and BAB-12 has an obvious trend for the flotation separation of lepidolite and gangue minerals at the dosage of 4:1,1:1 and 3:1;In order to further expand the separation effect,in the flotation test of sodium hexametaphosphate,citric acid and sodium silicate,sodium hexametaphosphate showed a strong inhibition on potassium feldspar and quartz,but had a small impact on the flotation of lepidolite.IR analysis and zeta potential results show that BAB-12 collector has strong electrostatic adsorption on the surface of lepidolite,potassium feldspar and quartz,and the combined collector of Na OL and BAB-12 has a strong synergistic effect on the surface of lepidolite,while the effect on potassium feldspar and quartz is weak,mainly physical adsorption,and Sodium hexametaphosphate can be adsorbed on the surface of potassium feldspar and quartz to further inhibit the adsorption of the combined collector,expanding the difference of floatability.The contact angle measurement results show that BAB-12 collector can increase the contact angle of the surface of lepidolite to 83.3°,showing excellent hydrophobicity enhancement ability;The contact angles of the combined collectors on the surfaces of lepidolite,potassium feldspar and quartz were 83.9°,58.1°and 61.3°,respectively.The measurement results of adsorption capacity show that under the BAB-12 collector system,the adsorption capacity of the three minerals on the surface is relatively large.When Na OL is added,the difference between the adsorption capacity of lepidolite and potassium feldspar and quartz on the surface is more obvious,thus realizing the effective separation of lepidolite and gangue minerals.