关键词: 石英, 铝离子, 油酸钠, 活化

Abstract: In order to describe the effect and mechanism of aluminum ion on quartz flotation in the system of sodium oleate，quartz flotation tests in the system of sodium oleate were carried out with 0.038~0.074 mm quartz pure mineral,and the mechanism was analyzed from views of zeta potential tests,solution chemical calculation and infrared spectroscopy analysis.The results showed that ①sodium oleate did not collect quartz without activation of aluminum ion but excessive aluminum ion will have negative effect on collection of quartz because of the consumption of sodium oleate.②With the help of aluminum ion,quartz can be collected by sodium oleate under the alkalescent conditions,and increasing the concentration of sodium oleate can raise the recovery of quartz in flotation.③The recovery of quartz in flotation could reach 93.4% under the conditions of pH value 8.0,Al³⁺ concentration of 3.0×10^-4 mol/L and sodium oleate concentration of 6.25×10^-4 mol/L.④Without aluminum ion,the surface of quartz is negatively charged under the conditions of pH values from 2.0 to 12.0,so sodium oleate,anionic collector,can not float quartz.But when aluminum ion has been added,the zeta potential of the quartz surface becomes positive at pH values from 3.8 to 9.2,and aluminum ion adsorbed on the quartz surface becomes the active point of the quartz adsorbing sodium oleate,which improves the floatability of the quartz.⑤When the recovery of quartz flotation is high,the main form of Al³⁺ in solution is Al(OH)_3(S) and the content of Al（OH）²⁺ and Al(OH)⁺₂ are very low,indicating that Al(OH)_3(S) is the main component which activates quartz.⑥The infrared spectrum of quartz + sodium oleate is similar to that of quartz,and only the intensity of the absorption peak is weakened.The only characteristic peak is the peak of Si—O bond.The infrared spectrum curve of quartz + Al³⁺ + sodium oleate shows the —CH₂— stretching vibration absorption peak,—CH₂— bending vibration absorption peak,and —CH₃ and —C=O— stretching vibration absorption peak,which are the characteristics of oleate peak,indicating that oleate occurs adsorption in the quartz surface.

Key words: Quartz, Aluminum ion, Sodium oleate, Activation