铝离子对油酸钠浮选石英的影响及作用机理

为了揭示铝离子对油酸钠浮选石英的影响，并探讨影响机理，以0.038～0.074 mm的石英纯矿物为研究对象，进行了油酸钠浮选石英试验，并从Zeta、溶液化学和红外光谱分析角度对影响机理进行了分析。结果表明：①在无Al³⁺活化的情况下，油酸钠对石英没有捕收能力；Al³⁺过量会消耗油酸钠，进而影响对石英的捕收。②在有Al³⁺活化的情况下，油酸钠适宜在偏碱性矿浆中捕收石英，提高油酸钠的用量有利于石英浮选回收率的提高。③在矿浆pH=8，Al³⁺浓度为3×10^-4 mol/L，油酸钠浓度为6.25×10^-4 mol/L情况下，石英的浮选回收率可达93.4%。④未加入Al³⁺时石英在pH=2.0～12.0时表面带负电，因而阴离子捕收剂油酸钠不能使石英上浮；Al³⁺的活化使石英表面的Zeta电位明显上升，大约在pH=3.8～9.2时石英表面的Zeta电位为正值，石英表面吸附的Al³⁺成为石英吸附油酸钠的活性点，从而提高了石英的可浮性。⑤石英浮选回收率较高时溶液中Al³⁺主要赋存状态是Al(OH)_3（S），铝离子羟基络合物的含量很低，说明Al(OH)₃沉淀是活化石英的主要成分。⑥石英+油酸钠的红外光谱曲线与石英的红外光谱曲线相似，只是吸收峰的强度有所减弱，出现的也仅为Si-O键的特征峰。石英+Al³⁺+油酸钠的红外光谱曲线上新出现了-CH₂-的伸缩振动吸收峰和弯曲振动吸收峰，以及-CH₃和-C=O-的伸缩振动吸收峰，这些都是油酸根的特征峰，说明油酸根在石英表面发生了吸附。

Effect and Mechanism of Aluminum Ion on Quartz Flotation in the System of Sodium Oleate

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.